# Buying used Chevy Volt battery modules/pack questions



## Functional Artist (Aug 8, 2016)

A friend of mine wants to upgrade his 48V golf cart from lead to lithium & I suggested to get some Chevy Volt modules.

So, looking around I came across a pack from a 2014 Chevy Volt for ~$1,500.00
...but, the donor car had ~104,000 mi. on it 

What kind of capacity, would the lithium pack, in a car with this many miles on it have left?

Thinkin' about it/doin' some research, a 2014 Volt is advertised as getting ~38 miles on electric before the gas engine kicks in
...so, 104,000 miles divided by 38 miles would be ~2,736 discharge/charge cycles

I know these lithium packs usually are good for 2,000 - 3,000 discharge/charge cycles
...but, what kinda life would these modules have left?

Then, I've seen other packs advertised as coming from cars with ~60K miles on them (~$2,500.00)
...but, once it's removed from the car, they could be selling you/us whatever they have sitting on the shelf

How could someone know for sure, what their getting?
...or even be able to check anything more than the sitting voltage, with a MM, while @ the "scrap yard" before buying a used pack?


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## john61ct (Feb 25, 2017)

I would never rely on the reported history to guesstimate.

Cap test allowed or walk, unless the price is so low you don't mind risking a very short lifespan, like under 10% of equivalent new price.

Then again many are wealthy, and/or much less risk-averse than me


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## JMLee (Jan 26, 2021)

Functional Artist said:


> A friend of mine wants to upgrade his 48V golf cart from lead to lithium & I suggested to get some Chevy Volt modules.
> 
> So, looking around I came across a pack from a 2014 Chevy Volt for ~$1,500.00
> ...but, the donor car had ~104,000 mi. on it
> ...


I own a Volt and have spent a lot of time the researching the failure modes of these batteries. My opinion is the general degradation of these packs at 100k miles is very very low and if the car was scrapped due to the drive battery it will almost certainly be a single cell group (1 of 96) or the temperature sensors. Most likely split into 48V packs these would have !5 KWh capacity or better


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## Functional Artist (Aug 8, 2016)

Another buddy, another question, 
He has a 36V golf cart needing batteries & wants to upgrade to lithium.
What is the highest voltage that can be applied to a 36V golf cart?
I would say that a 36V set of lead acid batteries should/would top out ~40V (13.5V x 3 = 40.5V)

It looks like a 10S (3.7V) Lithium battery would be about the closest match (4.2V x 10 = 42V)
...but, there's not a lot of "high out put" (50A - 100A) 10S battery packs available 

So, I was thinking, would there be any issues with using a 12S (45V 50AH) module out of a Chevy Volt
...but, using a 10S battery charger & only charging it up to ~42V
...so, the voltage range would be ~42V (4.2V per cell) top charge, down to ~33V (3.75V per cell)

Would there be any issues with continuously not fully charging a lithium battery?


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## OR-Carl (Oct 6, 2018)

No, in fact lithiums are happiest if they are not ever charged to 100%. The battery I bought out of a mercedes B series is nominally something like 36kwh, but they were limited to 28kwh by the car's charger - presumably to increase the lifespan.


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## brian_ (Feb 7, 2017)

Functional Artist said:


> It looks like a 10S (3.7V) Lithium battery would be about the closest match (4.2V x 10 = 42V)
> ...but, there's not a lot of "high out put" (50A - 100A) 10S battery packs available


The Chevrolet Bolt has two sizes of modules, all using the same cells of course so the difference is how many are in series. The larger modules are 10S (eight of them) and the smaller modules are 8S (two of them). That means of the 60 kWh pack each large module is 10/96*60 = 6.25 kWh. The Bolt modules must be capable of over 400 amps (to meet the 150 kW peak motor demand at 360 V).


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## morvolts (Jun 19, 2008)

Ive run a 36v motor on 48v chevy Volt packs for quite some time.
Gasp,even using both a Lester 48v charger and a 36v charger.
The 36v charger wont over charge even if left on for 8 hrs,
however need to make sure the pack is balanced.
the 48v charger needs a shutoff nanny. Ive got mine set to 49.2v

Charging to 3.75v is ok but youre leaving a lot of capacity on the table.
Never run them below 3.4v and they will be happy.


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## morvolts (Jun 19, 2008)

I just purchased another Volt pack and it was at 381.6V
thats 3.975V per cell. This is pretty much what the system is charged to at factory settings.
What this shows is that the factory charge is less than 95% of capacity.
3,75V is around 89%


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## john61ct (Feb 25, 2017)

morvolts said:


> the 48v charger needs a shutoff nanny. Ive got mine set to 49.2v


Please post a link - data sheet or for purchase - to what you mean by that?

unless you just mean functionality built into every source that is properly called a charger?

Thanks


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## john61ct (Feb 25, 2017)

morvolts said:


> I just purchased another Volt pack and it was at 381.6V
> thats 3.975V per cell. This is pretty much what the system is charged to at factory settings.


Do you mean the EV manufacturer?

Or the data sheet of the cells themselves?



> What this shows is that the factory charge is less than 95% of capacity


only measured against a "Full" capacity based on a stop-charge spec that is way too high for good longevity



> 3,75V is around 89%


Wut? What kind of cap test is that based on?

Do you mean isolated and well rested?

With most li-ion chemistries at 3.6 - 3.7V nominal, that is usually not much above the Ah capacity midpoint

especially if using 3.4V at rest as your "empty".

I realize specific cells can vary a lot

but measurement methodologies IRL vary a lot more.


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## morvolts (Jun 19, 2008)

john61ct said:


> Please post a link - data sheet or for purchase - to what you mean by that?
> 
> unless you just mean functionality built into every source that is properly called a charger?
> 
> Thanks


its a lester 48v golf cart charger
the chargers with an OBC(3 wire plug) can be used with a charge controller.
Theres so many different models to choose from. Idea is to use what you already have for your cart.


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## morvolts (Jun 19, 2008)

john61ct said:


> Do you mean the EV manufacturer?
> 
> Or the data sheet of the cells themselves?
> 
> ...


Yes Chevy Volt Gen 1


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## john61ct (Feb 25, 2017)

morvolts said:


> Yes Chevy Volt Gen 1


I did not ask that?

Also, not talking about golf carts, have had zero exposure to that world.

Please link to at least one "charge controller" that is separate from the charger.

More than one would be great, and indicate which is better and why.

If you have time, thanks!


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## morvolts (Jun 19, 2008)

john61ct said:


> I did not ask that?
> 
> Also, not talking about golf carts, have had zero exposure to that world.
> 
> ...


this one has worked for use with the golf cart chargers
Keep in mind I use it to control a master relay,so as not to put any real load on it.









12V/24V Red DVB01 Digital Window Voltage Comparator / Voltage Measurement Module | eBay


Find many great new & used options and get the best deals for 12V/24V Red DVB01 Digital Window Voltage Comparator / Voltage Measurement Module at the best online prices at eBay! Free shipping for many products!



www.ebay.com






search for model DVB01,shop for the voltage and price that fits best.

this is also set at 3.4v for low voltage shut off.


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## john61ct (Feb 25, 2017)

morvolts said:


> Keep in mind I use it to control a master relay,so as not to put any real load on it.


Thanks, could you do the same for the master relay handling the 48V power loads?


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## morvolts (Jun 19, 2008)

john61ct said:


> Thanks, could you do the same for the master relay handling the 48V power loads?


yes just use the controller to do pilot duty 
Im using a DPST relay and the DVB01 to turn off the main contactor on undervoltage
and turn off the charger when it reaches a set point at charging.


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## john61ct (Feb 25, 2017)

morvolts said:


> yes just use the controller to do pilot duty
> Im using a DPST relay and the DVB01 to turn off the main contactor on undervoltage
> and turn off the charger when it reaches a set point at charging.


Sorry I wasn't more clear.

Could you please link to the relay/contactor model you control from the DVB01?

How much flowing current at 48V do you think it can abide and still have decent duty cycle lifespan?


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## morvolts (Jun 19, 2008)

john61ct said:


> Sorry I wasn't more clear.
> 
> Could you please link to the relay/contactor model you control from the DVB01?
> 
> How much flowing current at 48V do you think it can abide and still have decent duty cycle lifespan?


Its rated at 400A

several sellers of same product
this one offers 3 yr warranty(cross fingers they are even around in 6 months)









Universal Contactor Solenoid MZJ-400A for Heavy Duty Golf Cart 48V Professional | eBay


Find many great new & used options and get the best deals for Universal Contactor Solenoid MZJ-400A for Heavy Duty Golf Cart 48V Professional at the best online prices at eBay! Free shipping for many products!



www.ebay.com





Important thing is to stop before changing directions.
this will kill the contacts in no time.


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## Functional Artist (Aug 8, 2016)

I came across a low cost BMS for a 12S 44.4V Chevy Volt module (~$20.00 shipped) 
High Quality sealed 12S 44.4V BMS 15A 30A with balance water proof | eBay

Here is more info

*Lithium-ion 12s 15a BMS Board/LiFePO4 PCB 15a 38.4v/18650 Li-ion PCM 15a 44.4v*
Model: DL12S
common Version : common port for charge/discharge 
separate Version : separate port for charge/discharge
We can customize any PCB from 1S to 30S lithium batteries with different current. 

1. Overview
DL12S36V15A PCB is used for 12 series 36V LiFePO4 battery pack.
We can design it for various lithium batteries like LiFepo4, LiMn2O4, and Li-polymer etc.
The main functions are: over charge protection, over discharge protection, over current protection, short-circuit protection, temperature protection etc.
According to the customer request we can develop PCM in different sizes and structures.
BMS manufactured by high quality Mos and IC imported . Keep your battery long cycle serivce life time.

2. Advantage
Use top quality (A-level) protective integrated circuit IC, from the solution of Seiko of Japan.
Strong load ability, constant discharge current 15A, use high voltage resistance, low inner
resistance power Mosfet. The heat sink will greatly help cooling.
IC itself has power balancing function. The circuit is simple and reliable.
Typical voltage detection for each cell. So each battery will be prevented over charged or over discharged. Over current and short circuit protection
function is very reliable. Long time short circuit of the load won't affect the PCB and the battery. Temperature protection during charging and discharging.
Extreme low power consumption. The consumption of the whole device is less than 50uA.
PCB use high anti-corrosion, high water resistance, high impedance ESD conformal Coating.

[Hot Item] Lithium-Ion 12s 15A BMS Board/LiFePO4 PCB 15A 38.4V/18650 Li-ion PCM 15A 44.4V

My questions are:
If connected to a 12S Chevy Volt module via the BMS plug can/will the balance function simply "do it's thing"
...or does it only "balance" while/during charging?

Also, I noticed down in the FAQ section

"2.What is the balance function?
The working principle and function are as followings, when your one cell voltage is up to alarm voltage(Li-ion up to 4.18V, Life Po4 up to (3.6V), then the cell Balance starts to work, balance resistance starts discharge with 35ma(when balance discharge starts to work, BMS will starts a little heat up, which is the normal reflection), the cell is in both charging and discharging status, and others which are not reached to alarm voltage(Li-ion 4.18V, Life Po43.6V)are only in charging status, no discharging, when the fast cell voltage is reached to alarm voltage(Li-ion 4.25V, Life Po43.75V)BMS starts off power protection, all the other cells 
are all in stop of charging, this process will enable your battery charging in balance current, and your battery voltage are in balance status, but when your cell voltage difference are in a big range, then balance can not be functioning.
well"

So, if I'm understanding this correctly, it doesn't even initiate the balance function until the "alarm voltage" of ~4.18V per cell
...but, my charger is set to only charge these 12S modules up to 49,8V (~4.15V per cell) 
...so, it looks like the balance function would never activate (in this situation)


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## rmay635703 (Oct 23, 2008)

Functional Artist said:


> Another buddy, another question,
> He has a 36V golf cart needing batteries & wants to upgrade to lithium.
> What is the highest voltage that can be applied to a 36V golf cart?
> I would say that a 36V set of lead acid batteries should/would top out ~40V (13.5V


We would need to know the controller, some antiques can be WAY overvolted 

Next a FLA 36v lead pack can achieve up to slight north of 45volts directly after charging on a dumb charger, this means that even the wimpiest 36v controller can handle at least 45volts plus a small overhead 

If you look inside the car you might find a Curtis 1204 36/48 volt controller which can handle a full 60 volt FLA pack (75v max) but your charger will need replacement and you need to note the dcdc model as well.

The motor and other components shouldn’t care about the voltage you choose


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## john61ct (Feb 25, 2017)

Functional Artist said:


> it doesn't even initiate the balance function until the "alarm voltage" of ~4.18V per cell


Yes, Daly are not the worst out there for basic protection and reliability.

But if you want longevity, do not use non-adjustable BMS for balancing.

No need to balance every cycle anyway

do it periodically when your monitoring detects it's needed

using a dedicated balancer, a "hobby" balancing charger, or just do it manually with an adjustable power supply.

Top balancing is the default only because it is cheap to automate, IMO bottom balancing is better, so long as your charger has an HVC cutoff based on the ""weakest link" cell level voltage.


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## morvolts (Jun 19, 2008)

Functional Artist said:


> I came across a low cost BMS for a 12S 44.4V Chevy Volt module (~$20.00 shipped)
> High Quality sealed 12S 44.4V BMS 15A 30A with balance water proof | eBay
> 
> Here is more info
> ...


so question is which BMS has an alarm for a low cell.
the $2 8 cell hobby ones consume a lot of power to remain connected.
Thinking of perhaps making and breaking the common to them via a relay controlled thru the key on switch.
Then they would only monitor when key is on.


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## Functional Artist (Aug 8, 2016)

Well, my buddy with the 48V golf cart (converted to Chevy Volt Lithium modules 2- 48V 50AH)
...but, somehow, last week he drained them too low.

* I'm not sure if his low voltage cut-off is not set properly
...or if he just forgot & left the system "on" overnight?

When he brought them to me, they looked like this & showing 37.4V (~3.1V per cell)








Are these still usable in any way?
...or is there anything that "can be done" to make these usable?

** There are (2) of these modules (both showing 37.4V)
...so, they "drained" in balance too


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## floydr (Jun 21, 2021)

You might be able to apply a couple 1" (25mm) ratchet bands around the bottom and slowly recompress the lower and top of the cells slowly let the sit for a while the gases may reabsorb. if that doesn't work apply a low charge @ 1A while slowly compressing the packs back together again to normal size of the pack. A bands around bottom may have prevented the cells from expanding.
What are cell voltages all 3.11V? 3.11V isn't too low for a NMC it is lower than normal.
As long as the cell pouches haven't ballooned to much and there is no sickly sweet smell the modules might be saved.
I have no experience with Volt cells or modules. Just LG Modules from a LG RESU unit which were very low voltage 6 7s modules all under 12V/module.
I used an icharger X8 to recharge them, icharger now makes a x12 version so it would work on a 12s module.
Later floyd


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## Functional Artist (Aug 8, 2016)

No ballooning or sweet smell, just the moderate swelling (as seen in the pic)

Yes, there was a snug fitting 9" metal ban/box "wrapped" around the modules
...but, I removed it to relieve the pressure (I didn't know if they were going to keep expanding or even start ballooning)

* No noticeable change overnight (in cell/module size or voltage level)

Thanks for the reply 

I'll try to re-compress the modules & report back


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## kennybobby (Aug 10, 2012)

The cells were likely overcharged causing them to swell. It's not a reversible reaction so they can't be "repaired".

Why would you remove them from a tightly banded housing intended to _contain_ any swelling?

Good luck getting the "paste back in the tube"


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## Functional Artist (Aug 8, 2016)

I just got more info, the guys kid was running around on the kart 
...& when he brought it back, the meter showed the pack was @ ~25V

The guy tried to "save" the pack by quickly connecting the charger
...but, within a few minutes they heard popping sounds
...noticed that the modules were swelling 
...& stopped charging.

Then, they called me "freaking out" thinking that they were going to "blow up"

So, they were over dis-charged 
...& then, slightly re-charged

* I added the "tightly banded housing" to re-secure/re-pressurize the modules, help protect them & for mounting purposes, after removing the cooling channels
...but, it was not designed to contain "this" kind of pressure
...&/also, I didn't know if they were going to keep swelling to a "bursting point" 
...so, I thought relieving the pressure would be a "good" idea

** I understand that these modules are damaged, I was mainly wondering if they could still be used (like maybe with a reduced capacity)
...or if it was just plain dangerous to re-charge them (adding energy to damaged cells)


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## floydr (Jun 21, 2021)

I recovered 6 lg modules out of a LG RESU10h that were under 12V these are 7s modules testing the batteries/cells out of an LG Chem RESU- 10H system None were bloated just drained real low. I was under the impression that the gases might be absorbed back into the electrolyte. Recharge slowly. monitor the cells.


Functional Artist said:


> I just got more info, the guys kid was running around on the kart
> ...& when he brought it back, the meter showed the pack was @ ~25V
> 
> The guy tried to "save" the pack by quickly connecting the charger
> ...


So cells were around 2V? The Icharger X8 I used doesn't use a regular charge mode until the minimum cell voltage is above 2.5V. The Icharger have a "precharge mode"( not a precharge like an ev would have) that limits the amps the charger put out to .1A I think.
The battery was damaged, how much will take testing to determine.
The controller 40V high low voltage limp mode / with a low voltage shutdown 36V?
I am not an expert, just a hobbyist
Later floyd
PS recharge slowly checking cell voltages and cell temperatures. These modules may be recoverable then again may be garbage now.


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## remy_martian (Feb 4, 2019)

Those modules are not recoverable - they are garbage. Garbage few will take as salvage or even recycling.

Chalk it up to less gasoline money saved by going EV.

Charging risks a fire....you are not going to detect the localized hotspots during charging on a swollen cell. I certainly wouldn't have a kid anywhere near it even if you did succeed in reviving 10% SoC.

I might be interested in rescuing the cooling plates from the dumpster if they're not crushed/bent. Only need a few for study purposes....never seen one in real life.


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## Functional Artist (Aug 8, 2016)

Well, I already put a couple of ratchet straps around (1) of the modules & started re-charging it.

I'm using a 12V "trickle charger" on each of the (4) cell groups.

Group #1 started off @ 12.65V & after 5 min showed 12.74V 
...paying special attention for any sounds, smells or heat (didn't notice any)
...then, used the same procedure with group #2 & #3 (with the same results)

I did this several times until each cell group was @ 13.3V (39.9V) 
...& all still seems good

Then, I moved up to a 48V 2.5A SLA charger (connected to the entire pack)

When I started charging the meter showed 39.9V 
...after 15 min - 40.4V
...15 min - 41.0V
...15 min - 41.5V
...15 min - 41.9V
...15 min - 42.2V
...15 min 42.5V
...15 min - 42.6V (still didn't notice any smells, sounds or heat)


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## Functional Artist (Aug 8, 2016)

Oops, I left off
...now, I'm going to let it rest overnight 
...& re-evaluate the situation, in the morning.


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## floydr (Jun 21, 2021)

How much tension are the ratchet straps under? Will the recompressed module able to fit in the boxes the module was removed from? If you have an AC IR meter check the cells for IR. There may even be a datasheet on the cells/ modules which would give the IR of a new cell. A DC IR check is ok just not as accurate. Does the gas seem to be reabsorbing?
Let them sit after recharge for a month to check for self discharge. I would hesitate to use the modules under a heavy load probably would limit discharge to 1C. Are The modules outside while they sit overnight?
kennybobby and remy- martian Both say the modules are garbage now. They may be right.
later floyd


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## remy_martian (Feb 4, 2019)

That is not something I'd be doing indoors....


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## piotrsko (Dec 9, 2007)

If there is gas in the pouch, it vents, hence the smell. Afaik, they swell because the plates have oxided uncontrollably and loosening the straps and retightened further killed the cells because you now have oxide shorts internally.

You don have enough firefighting equipment for even outdoors.


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## Functional Artist (Aug 8, 2016)

Isn't DIYELECTRICCAR all about learning?
...& experimenting (safely)? (usually "outside" of the manufacturers specifications &/or recommendations)
...& then, sharing the info gathered?

This isn't a nuclear reactor (which, by the way, are perfectly safe "if" maintained "within specified parameters")
...it's just (1) 48V 50AH module
...& of course, "this" is being done outdoors (at least 10 ft from anything flammable or valuable)
(Um...doesn't everyone play with their "mini-nuclear reactor" outdoors?) 








At 9:00 this morning the module was at 42.3V (seems to have settled ~.3V overnight)
...but, when I connected the 48V 2.5A SLA charger, that I was using last night, it wouldn't light up or work at all.
(it was pretty warm when I shut it off last night) 

So, then ~9:15 I tried/connected a 48V 10A Lithium charger (I use this one to re-charge my Elmoto)
...& the meter showed 42.6V
...after 15 min. 43.1V
...another 15 min. 43.5V
...then, another 15 min. 44.4V
...45.2V
...46V
...46.5V
...46.9V
...47.3V
[email protected] 48V (I stopped charging)

Then, when I checked on them, ~2 hours later, the meter showed 47.2V 

So, now I'm going to just let it sit, & monitor it, for the rest of the day  

I have not noticed any physical difference in this module (sight, sound or smell) while performing this procedure
...they do not seem to be swelling any more
...but, they do not seem to be getting any smaller or thinner either


* Also, you'all got me kind of concerned now, because I have (2) of these 48V 50AH modules on my Elmoto
...(1) on my Hell-raiser kart
...(1) on my Land Speeder

** So, what should I expect "if" something "was" to go wrong with these modules? (any examples or videos?)


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## Zieg (10 mo ago)

Well in the world of RC lipos you just don't bother trying to save a puffed lipo, just dispose of it and replace. Of course those are much smaller and cheaper (at most a few hundred bucks).

But here is what can happen with them. Keep in mind these are maybe half the capacity of one of the cells you are working with:





















EV batteries seem to follow a similar M.O.


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## Functional Artist (Aug 8, 2016)

Thanks for the reply, I really appreciate any/all info

Do you know if the Lipo packs, in any of those situations were "puffed" or damaged before having issues?

Also, I'd be (probably others as well) interested in any situations where Chevy Volt, LG Chem., Lithium Manganese packs have exploded or gassed out 

Thanks, again


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## Zieg (10 mo ago)

I'd be honestly surprised if the specific chemistry in the Volt battery caused it to behave significantly differently than whatever those batteries were, at least as far as puffing/fire is concerned. For all we know they might even be the same chemistry.

Off hand, I do recall reading about the adventure the NHTSA had with a volt battery that went up in flames and took a couple nearby cars with it. I guess it got wet and that caused a small short, which allowed the batteries to self-discharge over several days, until it spontaneously went boom. It's s pretty interesting read: Case closed: NHTSA ends Chevrolet Volt fire investigation


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## Duncan (Dec 8, 2008)

The battery that went on fire had massive physical damage! 
I would cycle those cells a couple of times OUTSIDE - then if they responded correctly just use them

I'm overloading my Volt cells by quite a bit (1200 amps)
Just taken the battery out and checked all of the cells - all within 0.01v - with no BMS or balancing

These are a completely different chemistry to the LiPoly fire bombs


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## remy_martian (Feb 4, 2019)

Functional Artist said:


> * Also, you'all got me kind of concerned now, because I have (2) of these 48V 50AH modules on my Elmoto
> ...(1) on my Hell-raiser kart
> ...(1) on my Land Speeder
> 
> ** So, what should I expect "if" something "was" to go wrong with these modules? (any examples or videos?)


You're an above average fabricator, so:








😂

fwiw, my outdoors comment was not aimed at you, because I assumed you had a lick of sense (jury's still out on that one), but at noob followon thread readers. Li-ion experimentation is not an indoor hobby.


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## Functional Artist (Aug 8, 2016)

Well, I've been waiting for hours now, for an "Earth shattering KABOOM!" (JK, just monitoring) 
...but, not a peep 

Follow up info:
2:00 - 47.2V
6:00 - 47.1V
9:00 - 46.9V
12:00 - 46.8V
...& still no sounds, smells or change in appearance


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## remy_martian (Feb 4, 2019)

Looks like you have yourself a $2000 countdown clock
😂


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## floydr (Jun 21, 2021)

Functional Artist said:


> Do you know if the Lipo packs, in any of those situations were "puffed" or damaged before having issues?


Video 2 was an intentional overcharge ( aggressive overcharge stated on the Youtube channel)
Video 3 extremely low voltage 5V for 4s or 6s battery. As experienced drone users they should have never had left the low voltage battery sitting on a counter. or if 5V was cell voltage extreme overcharge

later floyd


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## Duncan (Dec 8, 2008)

Just thinking here
The FIRST thing that you need to do is to pop off the black plastic "lid" and measure each cell - if they are all the same voltage then you are probably ok

The problem when you overdischarge a battery is when one cell hits zero and is then reversed by its brothers - instant death
but a quiet death
the noisy death is when you charge the battery with the dead cells

so when you are doing your recharging of the suspect battery don't just measure the battery voltage measure the cell voltage as well


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## Functional Artist (Aug 8, 2016)

floydr said:


> Video 2 was an intentional overcharge ( aggressive overcharge stated on the Youtube channel)
> Video 3 extremely low voltage 5V for 4s or 6s battery. As experienced drone users they should have never had left the low voltage battery sitting on a counter. or if 5V was cell voltage extreme overcharge
> 
> later floyd


A couple of those videos seemed kinda "staged" to me
...or done "on purpose" just for entertainment (or youtube views)

Like stomping on lithium batteries while their gassing out? WOW!

* I can't find it now but, I remember watching a video of a guy that does all kinds of "bad things" to a Pouch type Lithium battery (Volt or Leaf)
He chopped with hatchet & shot holes in it etc.) 
...& no Earth shattering KABOOM!
...or out gassing


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## Functional Artist (Aug 8, 2016)

Duncan said:


> Just thinking here
> The FIRST thing that you need to do is to pop off the black plastic "lid" and measure each cell - if they are all the same voltage then you are probably ok
> 
> The problem when you overdischarge a battery is when one cell hits zero and is then reversed by its brothers - instant death
> ...


Yes sir, 
The first thing I did, before ever connecting a charger, was to check the individual cell "groups" (3 cells welded together "in series")
...& all 12 cell groups were pretty well balanced, with nearly identical voltage readings

I also, checked the individual voltage of the cell groups yesterday (~6:00 pm) while the battery pack was "resting"
While the whole pack showed 47.1V
...all of the cell groups showed 3.96V (still pretty well balanced)


----------



## Duncan (Dec 8, 2008)

Functional Artist said:


> Yes sir,
> The first thing I did, before ever connecting a charger, was to check the individual cell "groups" (3 cells welded together "in series")
> ...& all 12 cell groups were pretty well balanced, with nearly identical voltage readings
> 
> ...


the three groups are "in parallel" - so they all have the same voltage! - best to simply treat the three as one cell

I am very very impressed about just how little the volt cells vary despite my abuse


----------



## Zieg (10 mo ago)

Oh the one that blew up while charging was absolutely done intentionally. I was just looking for videos showing what a 3.7v lithium pouch cell _can _do (except the Tesla video, which we all know doesn't use pouch cells but just shows the same kind of reaction at a larger scale).

All that said, I have gen 2 Volt cells myself, and would be very happy to hear that their internal chemistry is sufficiently different that it's not possible for them to go up that violently!


----------



## Functional Artist (Aug 8, 2016)

Duncan said:


> the three groups are "in parallel" - so they all have the same voltage! - best to simply treat the three as one cell
> 
> I am very very impressed about just how little the volt cells vary despite my abuse


Yes sir,
The 3 cells are "in parallel" (oops, it's still early) 
...& to be treated as (1) cell 

I agree these LG battery modules are well designed, matched & produced


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## Functional Artist (Aug 8, 2016)

I checked on the module this morning (still sitting out in the middle of the yard)
...& still no noticeable change (sight, smell or sound)
...& the voltage is still at 46.8V (same as ~11:00 last night)

I guess the next step would be to monitor it while dis-charging
...but, before that, I'm thinking I should create a "press" to clamp it together (better)

Like with a couple of 1/8" thick steel plates, on the ends
...with let's say (4) 1/2" rods (2 on each side)

It seems like this would provide a more "even" pressure across the pouches (to help re-compress them)
...& can be more evenly & incrementally increased (plus, I need my ratchet straps back)  

How much pressure can these things take?

Anything I should be watching for?


----------



## Duncan (Dec 8, 2008)

The bottom is clamped with four M6 studs - the top started as a steel band

I would suspect that the steel band would have had a very high "stiffness" and would have resisted a very very high load

I'm reconfiguring my modules at the moment - and I would be very interested in just how "stiff" you find the top of the modules

I would start with some M6 studding and just see how tightening up the nuts works 

Very interested in what you find - I was thinking about using some strapping instead of the steel bands - not sure if that will be "stiff" enough


----------



## kennybobby (Aug 10, 2012)

Functional Artist said:


> Yes sir,
> The first thing I did, before ever connecting a charger, was to check the individual cell "groups" (3 cells welded together "in series")
> ...& all 12 cell groups were pretty well balanced, with nearly identical voltage readings
> 
> ...


This is why folks get scared when reading your posts:
1. not understanding the difference in series and parallel cells to create the "groups" aka Cells
2. considering "nearly identical" as a measurement from which to start charging
3. taking measurements that don't make sense, 47.1/12 is only 3.925 VpC if all are equal
4. assuming it is "pretty well balanced" based on ? data?

which Cell was 3.96 ? If all were then you need a different voltmeter; check, verify, calibrate your voltmeter with a known reference. 

Let the pack sit for a week while you sort out your voltmeter and strap situation, take daily readings of Pack and all the Cells.


----------



## Functional Artist (Aug 8, 2016)

kennybobby said:


> This is why folks get scared when reading your posts:
> 1. not understanding the difference in series and parallel cells to create the "groups" aka Cells
> 2. considering "nearly identical" as a measurement from which to start charging
> 3. taking measurements that don't make sense, 47.1/12 is only 3.925 VpC if all are equal
> ...


Well, I'm human & sometimes (some days more than others) I mis-speak, Oops 
...but, I do "way more" than most folks 
FYI: while I was monitoring or "babysitting" this module I also did:




...so, there are many more opportunities for me to mis-speak  
.
(1) Yes, I know the difference between series & parallel
..but, I think (by now) with the dozens (& dozens) of electrical projects that I "have completed" I'd get some "slack"

(2) I noted that the cell groups were "all" nearly identical in balance
...& none of the cell groups were significantly higher or lower than the others
...by physically checking them, individually (not just dividing 47.1 by 12)
...so, it seemed safe to proceed (with caution, of course)

(3) I just noted the data, as presented by my low cost "free" HF meter(s) (as seen in the pics)
* Thinking about it, maybe the difference was that I had (1) meter constantly connected to the entire pack to monitor pack voltage
...& then, I used a separate (same type free meter) to check the individual cell groups

(4) based on the actual, individual readings, I got directly from the cells 

* I like (you, Brian, Major etc.) better when you'all are more helpful 
...not just criticizing or correcting (not just me but, fellow forum members in general)
...just sayin' 

** I try, test, experiment & learn just about everyday
...sometimes it's what works
...& many times, it's what don't work (like: note to self, don't do that again)


----------



## floydr (Jun 21, 2021)

Functional Artist said:


> my low cost "free" HF meter(s


Nothing wrong with the meter  consistency is more important 
Calibrating the DMMs against a known voltage, check voltage of same battery with both DMMs. This would be good to do every time you change the 9V battery in a DMM. 
I have a few HF meters free ones and a $39 special HF meter. Did buy a dc clamp meter off of ebay.

Later floyd


----------



## remy_martian (Feb 4, 2019)

I used the HF el cheapo freebie in my toolbox (too lazy to go in the house for the HP) to measure my Model S modules just after harvesting them and found big discrepancies of hundreds of millivolts in module voltages. 

A few days later I remembered to bring the HP out and all were within 10mV of each other.


----------



## floydr (Jun 21, 2021)

remy_martian said:


> I used the HF el cheapo freebie in my toolbox (too lazy to go in the house for the HP) to measure my Model S modules just after harvesting them and found big discrepancies of hundreds of millivolts in module voltages.


Could have the battery in the HF DMM have been low? 
Would explain the wide range of module voltages. HF DMM's are good for the price, Just not as accurate as a HP or flukes meter. 
Later floyd


----------



## Functional Artist (Aug 8, 2016)

I've been monitoring the module "on & off" all day.
Started off @ 9:00 am - 46.8V
...11:00 47.1V (getting warmer outside)
...12:00 47.2V (now bright sunshine)
...then, 12:15 I noticed 47V (heavy cloud cover)
...1:00 47V (sun coming back out)
...2:00 46.9V (I put a cover/shade over it)
...3:00 46.9V
...5:00 46.9V
...8:00 46.8V (sun setting)
...10:00 46.6V (after dark)

So, it seems like ambient temperature may affect the voltage level of the module a little bit. 

While monitoring, I made up a "press" (to clamp it together better)
...& also, installed it (~8:00pm this eve)

* This module was "expanded" to ~14" @ the bottom (with the straps off)
...then, after "pressing" I got it down to ~9 1/8" at the top
...& ~9 1/4" at the bottom (they are usually ~9" top & bottom)


----------



## floydr (Jun 21, 2021)

The clamps you made look great and work much better than ratchet straps. how much pressure would you say is on the battery pack? If the gases do reabsorb probably would be wise to tighten the nuts by hand one turn at a time. Even pressure
Later floyd


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## floydr (Jun 21, 2021)

A torque wrench could be used for the final tightening, even to gauge how ftlb/nm of torque the nuts are now at. Also using a torque wrench you can be sure of even tightening of the nuts. Fingers are crossed that the batteries are both recoverable.
Later floyd


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## Duncan (Dec 8, 2008)

So what thread and how much torque?


----------



## kennybobby (Aug 10, 2012)

Well done, that is a nice looking clamp fixture.

The voltage looks to be holding steady is a good sign that maybe there is no internal shorting damage to the current collectors in the cells. 

Give it a week and see how well it holds up, then you can do some load tests to measure capacity, etc. It might work okay for the cart.

One idea to consider, what about backing off the clamp to ~9-1/2" at top and bottom, or maybe 10" at both. This would still be applying clamping force but allow the internal pressure to spread evenly inside the cell packages. If they are tightly clamped to close the gaps, this reduces the volume available for gas and _increases the pressure at the edges and seams_. The plastic bags are tough but the seams would be the weak links. Maybe this is not a good idea since you have already been able to compress them with no leak, and they need to be tight when used in a vehicle to avoid internal motion of the layers.


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## remy_martian (Feb 4, 2019)

Duncan said:


> So what thread and how much torque?


I sense imminent pressure and force calcs...
🤓


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## floydr (Jun 21, 2021)

Duncan said:


> So what thread and how much torque?


Aren't chevy volt batteries/modules in original form held together by 4 long 8mm bolts? Would be simple to make up new end pieces for the modules, you could make new end clamps and plates. Measure the module and two end piece add 15 to 20 mm* of length get new bolts/threaded rods if the OEM bolts aren't available/are too long . Tighten so the module isn't compressed, yet it would be constrained from excessive expanding. Foam insulation on the back sides of the plates to allow for expansion and contraction of the modules?
Expanded/swelled modules would take a different approach as demonstrated by Functional Artist.
*This additional length could be shorter or longer as needed.
Later floyd


----------



## Duncan (Dec 8, 2008)

Four long 6 mm bolts at the bottom and a strip of steel at the top - the steel band is just the right size to tap on or off the top of the modules


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## Functional Artist (Aug 8, 2016)

These modules are actually held together by (4) ~1/4" dia. bolts with 10mm "nuts" on each end.








* I think these bolts are more for compressing the rubber seals that make up the coolant channels, together.
...& if not for these coolant channels I think they would have/could have used the "steel band" around the bottom too.

I have just added pieces of angle Iron, to the bottom ends of modules, to re-secure them
...& they also, provide "flanges" for mounting








I used 3/8" rods to "squeeze" the top of the module together
...& 1/2" rods at the bottom (for additional strength)
I'm not sure about the pressure. I just kept turning the screws until it until it was back to ~9' wide (like original)

* Yes, after I did it, I was thinking, maybe I should have "squeezed" it a little more incrementally
...but, I didn't 
...so, I've just been monitoring it 
...& it's still sitting ~46.7V 

As for the other "slightly puffed" module 
...I did some exploring 








Here is a video


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## floydr (Jun 21, 2021)

Very good video, showed what you were doing as you were doing it. Too many videos only show the end result or the actual work is obscured by something. HF sells a nylon pry bar set ~8 dollars. Would be safer than a metal srewdriver to use as a pointer.
Later floyd


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## Duncan (Dec 8, 2008)

Functional Artist said:


> These modules are actually held together by (4) ~1/4" dia. bolts with 10mm "nuts" on each end.
> View attachment 131894
> 
> * I think these bolts are more for compressing the rubber seals that make up the coolant channels, together.
> ...


Are you sure those rods are 1/4 - I was fairly sure they were M6 - even Chevy has had to move out of the stone age imperial threads


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## Functional Artist (Aug 8, 2016)

Duncan said:


> Are you sure those rods are 1/4 - I was fairly sure they were M6 - even Chevy has had to move out of the stone age imperial threads


Yes, the stock Chevy "rods" are metric (just a little bit smaller dia. than 1/4")

FYI: when breaking down a full Chevy Volt pack, into the individual modules, I've used a 1/4" die to put threads on them "stock" Chevy "rods" after shortening them
...& also, have used 1/4" rod material, to make my own "rods"

5/16" rod material will not fit.


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## Duncan (Dec 8, 2008)

Functional Artist said:


> Yes, the stock Chevy "rods" are metric (just a little bit smaller dia. than 1/4")
> 
> FYI: when breaking down a full Chevy Volt pack, into the individual modules, I've used a 1/4" die to put threads on them "stock" Chevy "rods" after shortening them
> ...& also, have used 1/4" rod material, to make my own "rods"
> ...


Converting a nice M6 thread to an antediluvian 1/4 inch!! terrible!


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## remy_martian (Feb 4, 2019)

I believe the Bolt EV threaded rods are also 1/4" threads, despite the entire car being designed in S Korea.


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## Duncan (Dec 8, 2008)

remy_martian said:


> I believe the Bolt EV threaded rods are also 1/4" threads, despite the entire car being designed in S Korea.


I would be surprised - as far as I know the USA is now the only country still using the old Imperial system!!


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## remy_martian (Feb 4, 2019)

Likely some supplier out there has a special Swiss screw machine tooled to nonmetric-thread the ends of long rods for cheap. 

The LG chem cell holders are definitely not 6mm, but 6.35mm if you wanna be metric 😂


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## piotrsko (Dec 9, 2007)

If they are single point, just move the carriage differently, otherwise just change the threading die. Bolt and nut makers don't care what you order. Pretty sure a 1/4-28 nut fits the Volt hardware enough to work or perhaps it was the other way. I forget stuff after 5-7 years


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## Functional Artist (Aug 8, 2016)

kennybobby said:


> Well done, that is a nice looking clamp fixture.
> 
> The voltage looks to be holding steady is a good sign that maybe there is no internal shorting damage to the current collectors in the cells.
> 
> ...


Thanks! I always appreciate it when the "craftsmanship" gets noticed  
I agree the voltage seems to be holding steady on this module
...& I will try some "light" load tests, soon.

Also, I actually appreciate correction "if" & when I "mess up" (I do not want to spread/post false info)
...just not criticism (maybe it's my "artist" side) 

*As far as, posting & videos, I do so much stuff, that sometimes I forget "how" (or even "why") I did something
...so, I post info & make videos (it's kinda like a digital notebook)

Hopefully, some info I post helps others
...but, I do it mainly for personal reference
...so, "if" or when needed, I can look over the info or videos that I posted (& any helpful &/or corrective responses)

Like, when you helped me figure out the required resistor values, for a pre-charge circuit 
That was SUPER HELPFUL 
...& I've referred back to & re-read that thread many times, since


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## Functional Artist (Aug 8, 2016)

Duncan said:


> Converting a nice M6 thread to an antediluvian 1/4 inch!! terrible!


When breaking down a complete Chevy Volt pack, you have to cut the "stock" rods down to a usable size 
...& then, re-thread the cut end (to make it a "bolt" again) if you want to re-use them

So, I tried a 1/4" die 
...& it seemed to "work" 

* It "bit" onto the material, good
...& seemed to cut some decent threads

Plus, I already had (1) on my toolbox
...& a bunch of 1/4" nuts too

Here in America, we have standard hardware "coming out of our ears".

FYI: our hardware stores have a whole isle of standard nuts & bolts
...but, only like (4) small drawers of the Metric stuff

"If you live on an island, you eat a lot of fish"
...or "work what you have to work with"


----------



## Functional Artist (Aug 8, 2016)

floydr said:


> Very good video, showed what you were doing as you were doing it. Too many videos only show the end result or the actual work is obscured by something. HF sells a nylon pry bar set ~8 dollars. Would be safer than a metal srewdriver to use as a pointer.
> Later floyd


Thanks! 
...another page in "my digital "notebook" 

* I agree using the unprotected metal screwdriver was NOT a good idea 
...or showing a proper/safe practice, for others to follow

Yes, I shall get/use a proper "pointer" from now on  
...good correction


----------



## kennybobby (Aug 10, 2012)

What is the voltage reading today? Before you start doing load testing, let it sit for the week after you took it off the charger to see how well it holds with no load. This will give you an idea of the self-discharge rate.


----------



## Functional Artist (Aug 8, 2016)

As for, the 2nd slightly puffed module (that I dissected) I've been thinking of ways I can maybe re-use some of these cells 
...& also, maybe do some "testing" on some of them, too

Like:
I have previously thought about making/testing a 14S batt pack, out of these type cells
...because the 12S modules are actually 44.4V (nominal) 
...with a top charge of ~50V

Which is kind of "lackadaisical" for a 48V system

FYI: the top charge voltage of (for example) a 48V SLA batt pack is ~54V
...& so, by only using a 50V (top charge) batt pack I'm/your "missing out" on the power (& capacity) of them extra 4V

So, I was thinking that maybe, I could use/try (14) of these cells to create a (14S) 48V ~15AH batt pack
...that would have a top charge voltage of ~58.1V (4.15V x 14 = 58.1V) which would be a HUGE boost, over a 50V or even a 54V pack
...& then, try/test it on one of my karts with a little MY1020 48V 1,000W motor (ie. light load test)

* I usually get ~30 min of good "run time" using (4) 12V 12AH SLA's
...so, I'm thinking that I should be able to get a bit more "run time" out of a 48V 15AH Lithium pack 

** Yes, I remember these cells may be/are "damaged" 
...but, this is/would be "only a test"  
...& I have them "at my disposal" 
...so, let's do learn some stuff from them  

The peak Amperage draw of a 48V 1,000W motor is ~30A 
...but, I've seen them draw well over 100A (in other "tests") 

The average draw is usually ~20A (1,000W/48V=20.83A)
...but, once you're up to speed, they seem to draw a little less (like maybe ~15A)

*** As far as I understand, these 48V ~50AH modules, are made up of 36 - 3.7V (nom) ~15.5AH cells
...& when they connect (3) of these cells "in parallel" it creates a 3.7V (nom) ~50AH cell group
...& then, when (12) of these 3.7V (nom) ~50AH cell groups are connected "in series" it creates a (3P12S) 48V ~50AH Chevy Volt Module, like the ones we are working with.

(Wow, that was a lot of info, hope I explained everything "understandably" & didn't "F" anything up)

So, anyone have any thoughts/ideas on a good way to re-connect these cells?


----------



## Functional Artist (Aug 8, 2016)

kennybobby said:


> What is the voltage reading today? Before you start doing load testing, let it sit for the week after you took it off the charger to see how well it holds with no load. This will give you an idea of the self-discharge rate.


I put the ratchet straps on Tue Aug 9 
...& started re-charging it with a 12V "trickle charger"
...then, on Wed, I topped it off to 48V with the 48V charger

* The 48V reading was with the charger connected
...& when disconnected, the module showed 47.8V

The next morning it had "settled" to 46.8V
...& according to my "data" it has been holding pretty steady at ~46.8V since

I just went & checked it this morning Sunday 
...& it in now reading 46.7V

So, it's been sitting for (4) days now
...& seems to still be holding pretty steady  

* Observation, 
The daily temps, around here, have been in the upper 80's all week
...but, today is much cooler (current temp is 63*)


----------



## kennybobby (Aug 10, 2012)

A single cell would be a good candidate for a load test. 

Charge it up to 4.xx volts or whatever top end you desire to test, then put a load on it to drain it down to your low limit. 

Monitor the current and voltage during the test keeping track of the time in minutes (6 or 30 minute intervals) also. 

Depending upon the test current, things will be slow to change during the early part of the test, but will be rapidly changing as the cell reaches the end, very rapid, meaning your time period between measurement samples will be in 6- or 30-seconds rather than minutes.

From that data you can calculate the discharge capacity of the cell to compare with the spec rating, find out how well they have held up.


----------



## kennybobby (Aug 10, 2012)

For connecting cells at the tabs, go check out Ripperton's motorcycle thread where he built his pack. He drilled or punched holes in all the tabs, then made clamping plates to hold the tabs together with screws. Just have to be very careful at all times when handling hot cells around metal tools, work surfaces, etc.


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## Functional Artist (Aug 8, 2016)

kennybobby said:


> A single cell would be a good candidate for a load test.
> 
> Charge it up to 4.xx volts or whatever top end you desire to test, then put a load on it to drain it down to your low limit.
> 
> ...


OK, sounds like a good start

I could probably use a 5V cell phone charger, for charging (1) single cell
...but, what to use as a "load"?

It seems like even a small motor would be "too much"
...how about maybe a small 12V (automotive turn signal) incandescent light bulb?
...or?


----------



## Functional Artist (Aug 8, 2016)

kennybobby said:


> For connecting cells at the tabs, go check out Ripperton's motorcycle thread where he built his pack. He drilled or punched holes in all the tabs, then made clamping plates to hold the tabs together with screws. Just have to be very careful at all times when handling hot cells around metal tools, work surfaces, etc.


Which thread, he has a bunch of them? 
..."clamping plates"?

I have NOT re-charged the 2nd module
...this is the one that I dissected into individual cells (2nd video)

All cells have been holding steady at 3.2V, for a few days now
...& I was not thinking of re-charging, until the cells were reassembled into a pack & re pressurized
...or for "other tests" 

* As for the single cell load test, I think that cell should be "constrained" or lightly pressurized (like in the "stock" module configuration) while re-charging & dis-charging


----------



## kennybobby (Aug 10, 2012)

i like to use old stove eyes from the thrift store. They are low resistance and can get glowing red hot without breaking. They will work even when plopped into a bucket of water if needed to dissipate heat.

If they have a resistance of ~8 Ohms, then wire 4 in parallel to create a load of ~2 Ohms. Then the load current for one cell would be about 2 Amps (it will decrease as the voltage drops, hence the need for periodic monitor/recording). If you want higher current then add more eyes in parallel.











Ripperton's racing motorcycle thread, i think it has an index in the first post to help find items of interest.


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## Functional Artist (Aug 8, 2016)

Update, 
module #1 of the "slightly puffed" packs is still holding steady at 46.8V (for ~7 days now)
&
I've been working on building a 14S 48V 15AH module out of 14 of the cells from module #2

I installed a 48V 50A circuit breaker, as a re-settable fuse
...& to be used as a "main cut-off switch" too

I also, installed a voltage meter, for monitoring & data collection purposes  








Here is a video of how it was done


----------



## Functional Artist (Aug 8, 2016)

Module #1 of the "slightly puffed" Chevy Volt modules has been sitting @ 46.8V (steady) for ~8 days now.

Now, I figured it was time for a light load test
...so, I removed the 48V 100AH batt pack off of my ElMoto
...& installed it 








Then, I took her for a nice slow & leisurely ride (~20 - 30MPH)
...& tried to mostly keep it in the ~20A - 30A range
...but, I saw it jump up to ~50A a couple of times

I took a pic of the PZEM-051 power meter, before I started off 
...& it showed 46.93V (pretty close to the 46.8V that the MM has been showing)








So, I rode her around for a while
...& ran her down to 44.5V

These modules are listed as 2kWh 
...so, I figured 500Wh used, was a "nice round number" for this test  








I checked several times during the ride (& after the ride & then hourly) for swelling, sounds, smells 
...& all seemed OK 

When I parked it ~7:00 this eve, the meter showed 44.50V
...then, after an hour ~8:00 this eve, the meter showed 44.67V
...at 9:00 44.65V
...at 10:00 - 44.65V
...& at 11:00 - 44.65V

Now, I'm not going to charge it
...or dis-charge it
...& just monitor it, for a day or so


----------



## remy_martian (Feb 4, 2019)

Hopefully, you're not gunna get lazy and fail to pull the pack out of your test mule in the event it lights off while charging.


----------



## piotrsko (Dec 9, 2007)

We aren't saying you can make this a one off case. We ARE saying it is a rare occurance that you will be sucessful. Dendrites are funny that way and are really hard to replicate consistently.

This site used to be full of don't do this at home scenerios. Batteries may have gotten safer, or people smarter.


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## remy_martian (Feb 4, 2019)

Those funny dendrites also grow with time because of the intense electric fields they produce...

I would never fully trust that pack for that reason alone, but exploiting it being serviceable is a bit of skill mixed with luck. That luck changes with time.


----------



## Functional Artist (Aug 8, 2016)

I started off explaining the situation & asked? 
"Are these still usable in any way?" 
..."or is there anything that "can be done" to make these usable?"



piotrsko said:


> We aren't saying you can make this a one off case. We ARE saying it is a rare occurance that you will be sucessful. Dendrites are funny that way and are really hard to replicate consistently.
> This site used to be full of don't do this at home scenerios. Batteries may have gotten safer, or people smarter.


I'm not doing anything amazing, I'm just performing some tests
...& sharing the data collected.

* Kinda like, I heard of this guy that put an old forklift motor in a car (& some folks said "you can't do that")
...then, some guys started overvolting them old forklift motors, that they put in their cars (again, you can't do that")

Some of them DIY electric cars with old forklift motors, just putted around (described as like driving a brick)
...but, they DID work

Then, some guys started upping the voltage (from 36V or 48V up into 100's of volts) on them old forklift motors
...& some guys ended up burning them up (some burned up many motors) until they tried different things 
...like, advancing the timing (& started being more successful)

Some folks (Duncan) overvolt them
...& then pump lots & lots of Amps thru them old forklift motors (kinda successfully)

Those were not "one off" situations, folks just tried different things (hopefully safely)
...& ain't we ALL glad that they "shared the data"  

Now, something that "couldn't be done" is "common place" 
...or even old news

As far as batteries go, IMO there is a BIG difference between the OEM batt packs specifically designed & produced for use with cars
...& someone that just ordered a bunch of lithium battery cells (Winston, A123, 18650's etc.)
...& assembled a battery pack with a potentially "mismatched" wide range of cell differences 

* Think like how resistors are "matched" or "binned" (to be within a certain range of each other)
...IMO battery cells should be closely matched, as well (like the OEM manufactures, that build batt packs do)



piotrsko said:


> If there is gas in the pouch, it vents, hence the smell. Afaik, they swell because the plates have oxided uncontrollably and loosening the straps and retightened further killed the cells because you now have oxide shorts internally.
> You don have enough firefighting equipment for even outdoors.


So, are these "oxide internally shorts" AKA dendrites?
...& would these dendrite formations be kinda like the "sulficating" that happens in Lead Acid batteries? (I believe this is when sulfur coats the lead plates inside of the battery)

So, lets discuss these dendrites
...how do they form?
...what do they do?
...can their presence or abundance be detected in a cell?


----------



## kennybobby (Aug 10, 2012)

i wish i could remember which episode, but Jack Rikard discussed dendrites over on EVTV.me, sharp copper dendrites grow on the anode sheet and puncture thru the plastic separator sheet and short into the aluminum current collector sheets of the cathode.


Also there is an episode where he shows video of the fire department at his shop after some cells caught fire while charging after being drained too low in one of his conversions. i don't remember if the cells had shown any signs of swelling, they were big prismatics not the pouches.
[edit: Talking to Paul he remembered that Jack had 2 fires, one LiFePO4, the other was a Better way pack.]


btw no lithium cells are made with vents to atmosphere (such as found on Pb acid), they are all sealed air tight. The relief valves (aka burst vents) are there to open in the event of swelling to prevent an explosion.


----------



## Functional Artist (Aug 8, 2016)

remy_martian said:


> Hopefully, you're not gunna get lazy and fail to pull the pack out of your test mule in the event it lights off while charging.


Of course, the pack is off of the bike & back in the middle of the yard (for monitoring)







...& the
The voltage settled to 44.4V (by the next morning)
...& has been holding steady since (for a couple of days now)  








* Also, I think that maybe, some of the "gasses" may have re-absorbed, because when I went to mount the module, on the bike, the lower brackets moved a bit
...& the bolts were only finger tight (they were "good-n-tight" when I "clamped it together, the other day)


----------



## remy_martian (Feb 4, 2019)

I see you left the pipes on the bike. Maybe you should build one of these for it: Electric Dodge Charger Concept's 'Exhaust' Is As Loud as a Hellcat V8. Here's How


----------



## Functional Artist (Aug 8, 2016)

You say:


remy_martian said:


> Those funny dendrites also grow with time because of the intense electric fields they produce...
> I would never fully trust that pack for that reason alone, but exploiting it being serviceable is a bit of skill mixed with luck. That luck changes with time.


I say:
So, lets discuss these dendrites
...how do they form?
...what do they do?
...can their presence or abundance be detected in a cell? 

Now, you want to discuss the "artistic choices" I made when building my ElMoto?

* IMO an old motorcycle just doesn't look the same, without them chrome pipes 
...& they don't weigh mush
...or take up any usable space


----------



## floydr (Jun 21, 2021)

Functional Artist said:


> ...how do they form?
> ...what do they do?
> ...can their presence or abundance be detected in a cell?


Dendrites form from disolved copper*/Lithium** being redeposited as elemental metals and potentially penetrating the SEI separator in the cells.
They can cause shorts, increased internal resistance, self discharge, increased heat. Internal resistance can be checked with an AC internal resistance meter (any of the YR103x+ models, SM8124A, RC3563 I use a YR1030+) increased internal resistance can be caused by increased dendrites. One would need a datasheet on the cells or a few good cells to tests to get an aveage IR of the cells.
* copper foil dissolves at very low voltages. How low does a cell need to get before this starts?
** unclear which penetrates the SEI I would imagine copper 
later floyd


----------



## remy_martian (Feb 4, 2019)

In a cell, think of it as a form of electroplating driven at a microscopic scale by high electric fields when a point defect initates them. 

Snowflakes, lightning bolts, and Lichtenberg figures (fractal wood burning) are all examples of dendrites forming in different media as the result of high e-fields.


----------



## Functional Artist (Aug 8, 2016)

I've been trying to learn more about Lithium-Ion batteries & these "dendrites" 
Here are a few things I found, that seemed to pertain:

"A Li-ion battery usually contains an anode made of graphite and a cathode made of lithium transition metal oxide. Under normal operation conditions, the lithium ions transfer between two electrodes for energy storage and release, giving the name Li-ion battery to this type of rechargeable battery. However, numerous Li-ion battery safety incidents have been reported, raising public concerns.

Among the reported incidents, internal short circuits caused by lithium dendrite formation were one of the reasons for battery failure. A Li-ion battery operating under abnormal conditions, such as overcharging or lower temperature charging, can lead to a harmful phenomenon called lithium dendrite growth or lithium plating. Lithium dendrites are metallic microstructures that form on the negative electrode during the charging process. Lithium dendrites are formed when extra lithium ions accumulate on the anode surface and cannot be absorbed into the anode in time. They can cause short circuits and lead to catastrophic failures and even fires. Several Samsung Galaxy Note 7 batteries caught on fire in 2016, and the investigation revealed the mechanism that lithium dendrites caused an internal short circuit. Capacity fade is another potential hazard of lithium dendrite growth. The lithium dendrite reacts with the electrolyte, causing it to decompose and triggering the loss of active lithium inside the battery. The capacity loss is an accumulating effect along with the gradual lithium dendrite growth."
Battery Power Online | A Look Inside Your Battery: Watching the Dendrites Grow
&
"Testing should be carried out at the appropriate level (cell, bank, string, module, battery, etc.) to confirm that the safety features being relied upon are working as expected to prevent not only the obvious hazards of overcharge, overdischarge and external shorts, but the more subtle internal short formation due to usage beyond their capabilities. When cells are used beyond their specifications, formation of lithium dendrites (overcharge) and electrolytic dissolution of copper with copper deposition on anode, cathode and separator (overdischarge) can become nucleation sites for further dendritic growth (internal shorts) that can result in localized heating, separator breakdown, imbalanced cell impedances and finally thermal runaway of cells".
https://www.sciencedirect.com/topics/engineering/lithium-dendrite

The common factor, that I noticed in both articles was: "operating under abnormal conditions" 
...& "due to usage beyond their capabilities" (basically, not used within the manufacturers recommendations &/or specifications)

Also, it seems like, there are several different Lithium battery chemistries, being used for different applications

So, I'm NOT speaking for or referring to ALL types of Lithium batteries, just specifically these Chevy Volt, LG Chem. LI-Mag type modules
...but, wouldn't manufacturers (like LG Chem.) have known about & took this dendrite issue into consideration, when choosing chemistries & designing huge battery packs to specifically motivate passenger vehicles?

So, (& I'm just asking) "if" these dendrites "are" such an issue (with this specific type of chemistry) then, why hasn't the many folks who have "operated these modules under (very) abnormal conditions" 
...&/or "(way) beyond their capabilities", had & reported more "catastrophic" issues? 

Like, Duncan's Device, EV engineering's S-10, numerous drag racers etc.

Again, keep in mind "I'm just asking" 
...& trying to understand more about the situation


----------



## remy_martian (Feb 4, 2019)

Dendrites aren't an issue until they become an issue
🤓

Dendrite formation is a form of electroplating. Needles produce very high e-fields, which is why they stay needles/whiskers, though they may branch.

LG Chem and others have specifications in terms of operating temperature and charge/discharge rates and levels. Most vehicle manufacturers adhere to those specs. 

Others, like Tesla, recognize they may be growing dendrites due to aggressive charge/discharge, so the cells are fused and the dendrite growth rate is minimized by design while abusing cells.

Didn't @Duncan identify and replace a "weak" cell or two, or am I thinking of someone else?


----------



## Functional Artist (Aug 8, 2016)

remy_martian said:


> Dendrites aren't an issue until they become an issue
> 🤓
> Dendrite formation is a form of electroplating. Needles produce very high e-fields, which is why they stay needles/whiskers, though they may branch.
> LG Chem and others have specifications in terms of operating temperature and charge/discharge rates and levels. Most vehicle manufacturers adhere to those specs.
> ...


OK, "Most vehicle manufacturers adhere to those specs" yes, that's going "by the book"
...but, in our DIY use situation "when" do they become an issue, is the question?

Here in the DIY world, one of the first things we do, when re-purposing OEM battery packs, is to remove the BMS or "factory installed safety system" 
...& (many times) re-configure them into "custom" packs, with a different voltage or capacity or physical lay-out & even use different sizes & lengths of cables & connectors etc.) than the manufacturer specified

So, we've "changed the equation" a bit (or in some cases, a lot)

Now, it seems like we're back to (just for example) Duncan (& other racers) who are not operating these type of battery packs "within them manufacturers specs" 
...&/or/also, the "novice" DIY'ers who Um...may have over dis-charged the Chevy Volt Lithium module in their golf cart

So, IMO it seems important for us to test, learn, understand & share, which specs (low voltage limit, high voltage limit, ambient temp. &/or internal temp., dis-charge rate, re-charge rate etc.) can be extended (& how far)
...& which ones should not (& why)

I don't think many of these questions are "in a book" (or in some cases have even been contemplated by the manufacturer)
...& as such can't be easily answered just by "them manufacturers specs"


----------



## kennybobby (Aug 10, 2012)

Do you have the cell datasheet--can you post a copy or link here for everyone to view?

Without that, how can you assume that anyone has operated outside the specs?

Cells are chemical reactions, so the chemistry determines specific performance and results. 

Some reactions are reversible, such as the normal charge and discharge within the operating region; and other reactions are not reversible such as from overcharging and under discharging. Swelling of a pouch cell is an indicator of the gas produced by the irreversible reaction of chemical breakdown in the electrolyte that can occur from either OC or UD.

As a friend of mine would say, an education is a big ticket luxury item, whether you pay up front for tuition to take college chemistry classes, or you learn the hard way from the school of hard knocks, either way it is expensive.


----------



## Functional Artist (Aug 8, 2016)

Well, looking around, I found this: (from 2014)

"It looks like the LG pouch cell part number is KC313x3, where x3 is the 3p of the KC313.
There are 13 current collectors coming off of each end of the jelly roll soldered/welded to a header adjacent to the external tab (hence the 13 in the part number). "
2012 Chevy Volt Battery:

Um...it looks like you have or had the data sheet for these cells (KC313)
...so, (if you still do) maybe you can post a copy or link here, for everyone to view?  

*The thread link(above) is kinda old (& long)
...but, has lots of Chevy Volt battery pack discussion & info


----------



## remy_martian (Feb 4, 2019)

Sure would be nice if Veronika (@D&VsEVJeep) would come play in our sandbox, tell us we're idiots 😂


----------



## floydr (Jun 21, 2021)

What do the pouch cells you recovered from the second battery pack have printed on them if anything. Many have a LG part number
later floyd


----------



## Functional Artist (Aug 8, 2016)

floydr said:


> What do the pouch cells you recovered from the second battery pack have printed on them if anything. Many have a LG part number
> later floyd


Well, I built another 14S 48V 15AH battery pack, out of cells #14 thru #28
...but, trying a different (& I think, improved) terminal connection method.  













Yes, there is printing on, (1) side of, every cell
Here is what's on cell #29
















& (another example) here's cell #30


----------



## floydr (Jun 21, 2021)

The LG part no. is LGZ P1.5B. LG battery part numbers usually begin with LG but not all. I doubt that a data sheet is available for us mere mortals. I think the other two line are shift and date codes. Would be nice to at least know the IR of a good cell and the bloated cells to compare to make an educated guess of the damage done. AC IR checking is more accurate than DC IR checking. Doubt it really matters which IR method is used. 
later floyd


----------



## floydr (Jun 21, 2021)

I would use a BMS on the battery even if you just use it to monitor individual cell voltages, some of the newer smart BMS's have IR of the cells, seen a couple that had resistance of the balance/voltage sense wiring not that you would be checking the IR of the cellswhile using the vehicle. The Ant BMS's I have use 4 10K thermistors, plus two on the PCB. So you can keep track of voltage and temp of your cells. Balance can be turned off or set to a high inbalance. It only balances when you charge the battery, since Volt cells are closely matched the balance function wouldn't be active much. Most smart BMS's have the much the same functions. Some are better than others.
Later floyd


----------



## Functional Artist (Aug 8, 2016)

Functional Artist said:


> Module #1 of the "slightly puffed" Chevy Volt modules has been sitting @ 46.8V (steady) for ~8 days now.
> 
> Now, I figured it was time for a light load test
> ...so, I removed the 48V 100AH batt pack off of my ElMoto
> ...


Update:
The "pressed together" 48V 50AH module, that I did the "light load" test on, has been sitting at the exact same 44.4V for (3) full days. (Fri., Sat & Sun)

* The 44.4V data was taken, using my HF MM 
...& the 44.65V measurements were taken when the module was still on the bike, using the onboard power meter. 
(that's why there's a slight difference)


----------



## Duncan (Dec 8, 2008)

remy_martian said:


> Dendrites aren't an issue until they become an issue
> 🤓
> 
> Didn't @Duncan identify and replace a "weak" cell or two, or am I thinking of someone else?


Just some Chinese aftermarket cells - I killed some and some just died
The Chevy Volt cells have been fine


----------



## Duncan (Dec 8, 2008)

floydr said:


> I would use a BMS on the battery even if you just use it to monitor individual cell voltages, some of the newer smart BMS's have IR of the cells, seen a couple that had resistance of the balance/voltage sense wiring not that you would be checking the IR of the cellswhile using the vehicle. The Ant BMS's I have use 4 10K thermistors, plus two on the PCB. So you can keep track of voltage and temp of your cells. Balance can be turned off or set to a high inbalance. It only balances when you charge the battery, since Volt cells are closely matched the balance function wouldn't be active much. Most smart BMS's have the much the same functions. Some are better than others.
> Later floyd


NOT convinced a BMS is useful
Two functions
(1) To warn me if a cell fails - I use a simple "Batt Bridge"

(2) To "rebalance" and "save" a failing cell - not at all convinced that is at all useful!!
IMHO if a cell is failing then it is going to fail - all that rebalancing does (slightly) postpone the inevitable

After six years of abuse (with ZERO re-balancing) my Chevy Volt cells are still within 0.01 volts of each other


----------



## Functional Artist (Aug 8, 2016)

Duncan said:


> NOT convinced a BMS is useful
> Two functions
> (1) To warn me if a cell fails - I use a simple "Batt Bridge"
> 
> ...


I'd have to agree. (these modules don't seem to need continual balancing)
I've been running Chevy Volt modules (without a BMS) on my ElMoto for ~5 years now, without any issues.

The Low voltage cut-off in the speed controller is set to ~36V (~3V per cell)
...& the Top charge cut-off is set to ~49.8V (~4.15V per cell) & is controlled by the charger.

Have you ever "tested" your Batt-Bridges? (to make sure that they actually work)
I could NEVER get the ones that I made to work properly.
How many are you using (1 per module) to monitor your pack?
Now, in 2022 isn't there something better? (more advanced)


----------



## kennybobby (Aug 10, 2012)

What happens in the event of UnderVoltage of a cell(s) in the Pack due to over discharging, is there a Turtle mode, such as a warning before shutting off the main contactors?

Does the Low voltage cut-off in your motor controller just immediately shut Off? In a car this could put the driver in a dangerous situation.

Evidently the LV C/O of the motor controller was not adequate for the job of protecting the cells from damage.

If you are racing on the drag strip then no BMS is necessary because YOU are the BMS. This is diy EVs.

But if you are making or selling a battery pack for inexperienced folks to use in a car or golf cart, then some protection, e.g. BMS, is required for human safety (and liability reasons).


----------



## Duncan (Dec 8, 2008)

Functional Artist said:


> I'd have to agree. (these modules don't seem to need continual balancing)
> I've been running Chevy Volt modules (without a BMS) on my ElMoto for ~5 years now, without any issues.
> 
> The Low voltage cut-off in the speed controller is set to ~36V (~3V per cell)
> ...


I use one batt bridge for the whole pack - and the circuit is dead simple - even I can't get it wrong

When I had the Headways I used one Batt Bridge for each "string" - (four strings) worked fine detected the cell failures


----------



## Functional Artist (Aug 8, 2016)

kennybobby said:


> What happens in the event of UnderVoltage of a cell(s) in the Pack due to over discharging, is there a Turtle mode, such as a warning before shutting off the main contactors?
> 
> Does the Low voltage cut-off in your motor controller just immediately shut Off? In a car this could put the driver in a dangerous situation.
> 
> ...


I seem to be making you "cringe" (a lot) I'm sorry, that's NOT my intention.

I always try to "think things thru" before doing them 
...& "if" any "red flags" appear, I DO NOT proceed (without further research & analysis)

Also, I'm NOT just "Willy Nilly" telling everyone "you don't need a BMS" just go "rogue"
I'm just sharing some of "my" experiences 
...& some of the data that I've collected (with a bit of personal commentary, here & there)

Yes, on my bike & karts, I'm the BMS
...& it's my responsibility to "keep an eye on things"

Maybe the newer golf cart SC's have a "turtle mode"
...but, most of the older ones, that I've see do not. (they just shut the system "off" at a pre-set level)

I helped the guy, who over-discharged & "puffed" his modules, with the Lithium conversion
...but, this spring he (unbeknownst to me) upgraded his SC & apparently, didn't set anything.

* I agree, for some (probably most) folks, the system should be set up as "idiot proof" as possible

Can you suggest an inexpensive BMS (or a couple of options) that would provide "inexperienced folks" with "some protection"


----------



## Functional Artist (Aug 8, 2016)

kennybobby said:


> But if you are making or selling a battery pack for inexperienced folks to use in a car or golf cart, then some protection, e.g. BMS, is required for human safety (and liability reasons).


So, (for example) something like this:
12S 36V 3.7V 3.2V Lithium100-200A Smart Battery BMS Board 485 BT APP CAN PC IP65 (~$250.00)
12S 36V 3.7V 3.2V Lithium100-200A Smart Battery BMS Board 485 BT APP CAN PC IP65 | eBay

But, check out the instillation instructions, IMO most folks "wouldn't have a clue" 
...or couldn't connect something like this themselves (& be successful) 
...plus, at ~$250.00 (about 1/2 of the retail cost of a 12S 48V 50AH module) 
Um...
So, the initial cost seems prohibitive, for your average golf cart DIY'er
...& then, it would probably have to be installed by a professional 
(if you can even find one, that would "tackle" something like this)

* Also, Orion (& others) makes & sells BMS's 
...but, FWIU they cost even more.


----------



## remy_martian (Feb 4, 2019)

Found this just now in my travels:

"The compression of the separator was found to adversely influence the charging performance of the Li-ion battery. When the compression ratio reaches 40 %, the charging performance of the battery decreased significantly."

I don't have access to the full paper, unfortunately:



https://www.sciencedirect.com/science/article/abs/pii/S2352152X22012531


----------



## Functional Artist (Aug 8, 2016)

"compression ratio"? 
...reaches 40% of what? (cell thickness, separator thickness)

Do you know if this info pertains to pouch cells?
...the cylindrical type of cells?
...or like them (exploding) cell phone batteries?

As far as these Chevy Volt modules, it seems like the compression ratio is determined by the thickness of the plastic frames, that they are housed in.


----------



## Functional Artist (Aug 8, 2016)

Functional Artist said:


> Update:
> The "pressed together" 48V 50AH module, that I did the "light load" test on, has been sitting at the exact same 44.4V for (3) full days. (Fri., Sat & Sun)
> 
> * The 44.4V data was taken, using my HF MM
> ...


Another Update
The "pressed together" (gray) (12S) 48V 50AH module been sitting at the same 44.4V for (7) days now.

So, I went ahead & charged it up (fully this time) to 49.1V 
...& then, let it sit all day (& it pretty much stayed at ~49V)

Then, that eve, I mounted it back on the bike & took it for a ride 

* I got on it much more this time (meter showed over 300A a few times) & went faster (~45 - 48 MPH)

Started off with ~49V in the module
...drained it down to ~44V
...racked up 1,000Wh (used)
...but, it looks like I only went ~12 miles


----------



## Functional Artist (Aug 8, 2016)

It seems most info (that I've found) on Lithium (or Copper) Dendrites, just kinda refers to lithium batteries "in general"
...but, (I'm finding that) there are many different types, shapes, chemistries & materials of lithium batteries available
...& IMO there has to be differences, both pluses & minuses, for different ones & in different use situations (still talking about Dendrites & their potential growth)

Here is some interesting info on Dendrites & visuals of their growth


----------



## remy_martian (Feb 4, 2019)

I don't have access to the full paper, so cannot answer your questions.


----------



## Functional Artist (Aug 8, 2016)

kennybobby said:


> Do you have the cell datasheet--can you post a copy or link here for everyone to view?
> 
> Without that, how can you assume that anyone has operated outside the specs?


This video has some interesting info on Chevy Volt modules

In it he mentions that the Idaho National Lab has been doing tests on these modules (a few years back)
...& also, that the info is public (maybe they have cell data or have tested individual cells & published that data)





* He also, discusses the differences in dis-charge curves between Lipo cells & these Li Mag cells

** Now, I understand why many of you guys have "balked" at the idea of using the voltage reading, of a pack, as a fuel gauge. 
It seems that LiPo cells have a very flat discharge curve (which has its benefits)
...but, the voltage reading, at any given time, wouldn't/couldn't really tell you anything.

Whereas these Chevy Volt Li Mag cells, have a more linear dis-charge curve
...& as such the voltage reading, at any given time, "is" a reflection of what's left in the pack.

*** That linear dis-charge curve also explains why my ElMoto's top speed is ~50MPH when the batt pack is fully charged (~49V)
...but, it will not reach 50MPH when the batt pack is at 50% charge (~44.4V)


----------



## Functional Artist (Aug 8, 2016)

Another Update on the "pressed together" (gray) (12S) 48V 50AH module 

After the 2nd dis-charge test, the meter showed 44V
...then, it "settled" to 44.75V & sat there for several days 

Before charging, just to be sure, I checked the individual voltage of all 12 cell groups (all registered at 3.74V)
...then, I went ahead & charged it up (fully this time) to 49.5V
...& then, let it sit all day (at ~49V)

Then again, just to be sure, I checked all 12 cell groups (all registered at 4.07V)

So, everything still looks "OK"
...so, last eve I mounted it on the bike (again) 
...& took it for another ride

* I didn't get on it as much, this time 
...but, still "zipped along" 
...kept up with traffic
...& went top speed (~45MPH)

Started off with ~49V in the module
...drained it down to ~44.5V
...racked up another ~1,000Wh (actually 1,017)
...& this time I went ~14 miles 





I checked on it this morning 
...& the pack registered at 44.8V

Then, I checked each 1/2 of the module
...& they registered at 22.4V (in each side)

Then, I checked all 12 cell groups individually
...& they all registered at 3.74V (each)
&
As a "quadruple check", I connected my digital balance meter 
...& it showed 22.4V in each side of the pack


----------



## Functional Artist (Aug 8, 2016)

floydr said:


> The LG part no. is LGZ P1.5B. LG battery part numbers usually begin with LG but not all. I doubt that a data sheet is available for us mere mortals. I think the other two line are shift and date codes. Would be nice to at least know the IR of a good cell and the bloated cells to compare to make an educated guess of the damage done. AC IR checking is more accurate than DC IR checking. Doubt it really matters which IR method is used.
> later floyd


What do you guys think of this method for checking the internal resistance of a battery cell or pack?
...it seems like it could be done (successfully) by the average DIY'er
...or I'm open to "better" suggestions


----------



## Functional Artist (Aug 8, 2016)

I want to check the internal resistance, of one of the cells (group) in this "slightly puffed" module
...& be able to compare the resistance reading, to a non-"puffed" module.

Would something like this be a better (more accurate) choice?
It's listed as a "RC3563 Internal Resistance Meter" (~$80.00)
Test parameters - AC resistance & DC voltage
RC3563 Internal Resistance Meter Lead Acid Lithium Battery Tester USA SELLER! | eBay 

I found a video about it 
...& showing it in use


----------



## floydr (Jun 21, 2021)

Functional Artist said:


> Would something like this be a better (more accurate) choice?


Yes, read this thread on second life storage forumhttps://secondlifestorage.com/index.php?threads/ir-meter-recommendations.10361/#post-71300 look for wolf he is a very knowledgeable member in that forum on IR meters. i would go with one of the YR1030+.YR1035+ meters but they don't seem to be available from sellers in the usa at the moment
later floyd


----------



## Functional Artist (Aug 8, 2016)

I mounted a "fresh" 48V 50AH Chevy Volt module on my ElMoto & gathered some data
...so, we can compare any differences between this "fresh" module & the "slightly puffed" module.


----------



## Functional Artist (Aug 8, 2016)

I ordered a RC3563 Battery Tester 
...& did some testing on the "slightly puffed" module 
...& on a "fresh" module 
...& recorded a bunch of data

The Voltage readings were very consistent
...but, the Internal Resistance readings that I got were (I'd have to say) inconclusive.

Here is the "slightly puffed" module data








...& the "fresh" module data









Let me know what you guys think
...of the meter
...of the data
...or if I'm doing something wrong


----------



## Functional Artist (Aug 8, 2016)

Why can't I get consistent Ohm readings from this RC3563 Battery Tester.

When I tested a battery (20) times
...& got (20) different readings


----------



## floydr (Jun 21, 2021)

Things I noticed with my YR1030+ IR meter
1) The meter tests more consistently when it is more than 50% charged
2)I have three different probes to test with a) sliding tester for small 18-20mm cylindrical cell under 80mm long. b) free hand probes for testing larger cells, c) Pliers action ones like you have. 
a1)The sliding one is the most consistent but slow
a2) the fee hand probes are much faster and once you get the hang of applying the same pressure every time almost as consistent. When you have thousand of cells to check it makes a difference.
a3) The Plier probes I have only used on large prismatic cells seem to work. haven't used the probes much
3) apply the probes in the same way, same pressure every time. when the voltage readings and the IR readings start to bounce around, Charge the meter 
IR meters help more when you know what the original cell/ battery IR was when new.
if you have a resistor Ω check it and see what the meter read It should read ±10% of the Ω of the resistor.
later floyd


----------



## Functional Artist (Aug 8, 2016)

floydr said:


> Things I noticed with my YR1030+ IR meter
> 1) The meter tests more consistently when it is more than 50% charged
> 2)I have three different probes to test with a) sliding tester for small 18-20mm cylindrical cell under 80mm long. b) free hand probes for testing larger cells, c) Pliers action ones like you have.
> a1)The sliding one is the most consistent but slow
> ...


Well, I tested a 10 Ohm 1W resistor, a couple of times.

The first time, I got 9.579 Ohm's








The second time, I got 9.580 Ohm's








...& the third time, I got 9.583 Ohm's








Hmmm...(3) different readings (real close but, still different)


----------



## kennybobby (Aug 10, 2012)

Does it give a tolerance rating on the resistor package, e.g. 5% ? If so then the value could be anywhere from 9.5 to 10.5 Ohms.

The value is also dependent upon temperature. Hold the resistor between your fingers and body heat will warm it up and the resistance will increase. Put one in the refrigerator or freezer to chill it down, then measure and the resistance will be lower.


----------



## Functional Artist (Aug 8, 2016)

kennybobby said:


> Does it give a tolerance rating on the resistor package, e.g. 5% ? If so then the value could be anywhere from 9.5 to 10.5 Ohms.
> 
> The value is also dependent upon temperature. Hold the resistor between your fingers and body heat will warm it up and the resistance will increase. Put one in the refrigerator or freezer to chill it down, then measure and the resistance will be lower.


Yes sir, this resistor has a gold (4th) color band 








...& according to the package gold = 5% (tolerance)








So, 9.58 Ohm's is within 5% of the rated 10 Ohm's  

Any comment on the (pretty consistent) 0.5XX (M) Ohm readings, I got, on the battery cell groups?
Also,
What does the (M) on some of the Ohm readings that I recorded, designate?


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## floydr (Jun 21, 2021)

Capital M stands for megaohm 1000000Ω, small m stands for Milliohm 1 Milliohm = 0.001 Ohm
Later floyd


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## Functional Artist (Aug 8, 2016)

Ok, it was a small (m) that I saw when checking the battery's
...so, their readings seem to be in Milliohm's (0.001 Ohm)
&
When I checked the resistor, there was no (m)
...so, their readings are in (full) Ohm's

Can you explain what the difference between a Milliohm & an Ohm?
...& why it's important when "testing" whole batteries & also, individual cells (or groups)?


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## piotrsko (Dec 9, 2007)

Pretty sure a color banded through hole resistor will be whole ohms.


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## floydr (Jun 21, 2021)

Functional Artist said:


> Can you explain what the difference between a Milliohm & an Ohm?


Milliohm 1 Milliohm = 0.001Ω 1ohm = 1000mΩ 


Functional Artist said:


> why it's important when "testing" whole batteries & also, individual cells (or groups)?


 If you know the internal resistance of a good cell (here a datasheet is best ) a baseline to compare the cells/modules with. Lower is better. The IR of a module should be the sum of the IR of the cells in a module. plus the resistance of the connections. When building a module/pack you want to have the same IR for each cell as close as possible. Again lower is better. Matched Cells in parallel matched parallel groups in series.
later floyd


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## Functional Artist (Aug 8, 2016)

Looking over/comparing the data between the "slightly puffed" 12S3P 48V 50AH Chevy Volt Lithium battery module
...& a "fresh" 12S3P 48V 50AH Chevy Volt module.
















The "slightly puffed" module seems to have a 0.009V difference, between the cells
...& the IR seems to be pretty consistent in the 0.5 (m) Ohm's range. 
&
The "fresh" module seems to have a 0.007V difference between the cells
...& the IR also, seems to be pretty consistently in the 0.5 (m) Ohm's range.

So, not much difference (according to these readings) between this "slightly puffed" module & a "fresh" module
...so, far anyways


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## floydr (Jun 21, 2021)

Charge the puffed 12s to the same voltage as the fresh module and take voltage/ir measurements again of the puffed 12s. SOC should be the same when comparing the two modules. But looks good so far. May not have been much damage at all. 
later floyd


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## remy_martian (Feb 4, 2019)

The gas to inflate the cell did not come from a bean burrito....something had to be displaced.


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## Duncan (Dec 8, 2008)

remy_martian said:


> The gas to inflate the cell did not come from a bean burrito....something had to be displaced.


If I'm remembering this correctly the inflation went away when the cells were gently clamped

So the gas left solution?? - and then slowly redissolved??

I would have bet good money that those cells were knackerred - but it looks as if THIS TIME they survived


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## piotrsko (Dec 9, 2007)

The vents for overpressure aren't one shot then fail, they close and reset, or at least in my 2011 pack. I've had the sweet electrolyte smell a couple of times when I was pushing 4.19 v @ cell couple of years back. Nothing since but I haven't popped the compression strap to check and my range test road got closed....


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## kennybobby (Aug 10, 2012)

Any pictures of the vent? Where is it located?


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## Functional Artist (Aug 8, 2016)

floydr said:


> Charge the puffed 12s to the same voltage as the fresh module and take voltage/ir measurements again of the puffed 12s. SOC should be the same when comparing the two modules. But looks good so far. May not have been much damage at all.
> later floyd


I charged the "slightly puffed" module up 
...& made sure the "fresh" module was fully charged too

* I used the same 48V 10A charger on both modules 
...& I noticed, that the "slightly puffed" module charged up to 49.0V when the green light (on the charger) came on
...but, the "fresh" module charged up to 49.2V, before the green light came on.

Now, I'll let them sit/settle/rest
...& just check on them, periodically


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## Functional Artist (Aug 8, 2016)

kennybobby said:


> Any pictures of the vent? Where is it located?


Um...I don't see any vents


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## Functional Artist (Aug 8, 2016)

I was thinking about having some "WARNING" stickers made up, for these modules
...maybe something like this:








...or does it need something more dramatic like "...or Violent Eruptions May Occur"


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## MarkDoronin (8 mo ago)

Functional Artist said:


> I want to check the internal resistance, of one of the cells (group) in this "slightly puffed" module
> ...& be able to compare the resistance reading, to a non-"puffed" module.
> 
> Would something like this be a better (more accurate) choice?
> ...


thanks for this video. It made it clear to me what to look out for. And about whether or not to buy non-new batteries, I'm more inclined to answer - no, if you buy only new batteries.


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## piotrsko (Dec 9, 2007)

Imho Warning label needs to mention potential death results.

Vent should be hole near negative tab or so I have been told anecdotally 8 years ago


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## Duncan (Dec 8, 2008)

MarkDoronin said:


> thanks for this video. It made it clear to me what to look out for. And about whether or not to buy non-new batteries, I'm more inclined to answer - no, if you buy only new batteries.


Hi Mark
The overall experience with "New" batteries is not good - as in a couple of orders of magnitude WORSE than buying batteries from a crashed EV

The auto makers have a very very expensive and effective system for ensuring that their batteries are all good and nearly identical - people selling "new" batteries to the public do NOT have that sort of system


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## Functional Artist (Aug 8, 2016)

piotrsko said:


> Imho Warning label needs to mention potential death results.


The Chevy Volt modules have this warning sticker on them








The entire battery pack cover has this sticker on it








...& even the connection panel, on the end of the pack, has basically the same sticker









Maybe add the "lightning strike guy" symbol (to left top of sticker)
...& maybe the Do Not Touch "hand" symbol too  

Here would be the Warning Sticker info for a 14S 48V module 
...& also, a 16S 60V module


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## Duncan (Dec 8, 2008)




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## piotrsko (Dec 9, 2007)

Your pack has them mine didn't. Has even less now, but I have a high voltage sign I removed from a weed pile next to a transmission line on the tonneau cover over the battery


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## Functional Artist (Aug 8, 2016)

piotrsko said:


> Your pack has them mine didn't. Has even less now, but I have a high voltage sign I removed from a weed pile next to a transmission line on the tonneau cover over the battery


I was just showing what warning stickers GM uses on these packs (as a reminder)  

I (so far) only use the individual 12S 48V modules 
...&/or (now) the 14S 48V & 16S 60V modules, that I built

The "warning" sticker idea was mainly to list the "specs" of these individual modules (right there, on the module, in plain sight)
...& also, the specs that MUST be maintained (...or "Violent Eruptions May Occur")

I don't think a "High Voltage" label is appropriate, for these small (48V & 60V) modules (or anything under ~72VDC IIRC)
...but, I think the "lightning strike guy" symbol would be appropriate (shock hazard)
...& the Do Not Touch "hand" symbol too (again, shock hazard)


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## kennybobby (Aug 10, 2012)

Why are there 2 threads talking about the same thing--why not just let the oldest one fade away and just concentrate on the latest one. Too much stuff jumping around between threads.


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## Functional Artist (Aug 8, 2016)

Because they are (2) different situations
...& I thought it would be difficult
...& also, found it to be confusing, to test, post results & discuss these different modules, in the same thread.

This thread (the oldest) is supposed to be about "stock" 48V Chevy Volt modules.

The newer thread is about the DIY modules, that I made out of some cells, harvested from Chevy Volt modules.

* The "limits" for a 12S 48V module are ~36V - ~49.5V
...whereas the "limits" for a 14S 48V module are ~42V - ~58.1V
...& the "limits" for the 16S 60V module are ~48V - ~66.4V


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## Functional Artist (Aug 8, 2016)

Functional Artist said:


> I charged the "slightly puffed" module up
> ...& made sure the "fresh" module was fully charged too
> 
> * I used the same 48V 10A charger on both modules
> ...


*1 month update*
I've been monitoring the (2) 12S3P 48V 50AH Chevy Volt modules weekly
...& it's been about a month so, I figured I'd post an update.

The "slightly puffed" module seemed to have dropped, just a bit to 48.9V (in the first week, right after charging)
...& the "fresh" module has been holding steady at 49.2V


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## Functional Artist (Aug 8, 2016)

The voltage levels of both the "slightly puffed"
...& the "fresh" 48V 50AH modules has been sitting nice-n-steady, for quite a while now at 49V & 49.2V (recorded using the red MM)

So, for a deeper look into these modules, I started monitoring them with a "double" Cell Checker.

The "slightly puffed" module shows:









So, the "slightly puffed" module seems to have a .02V difference between the module halves
...& only a .03V difference between "all" of the cells

The "fresh" module shows:









The "fresh" module seems to have a .01V difference between the module halves
...& only a .02V difference between "all" of the cells

* FWIU "if" there was any Dendrite growth or Internal Resistance issues
...there would be some kind of "RED FLAGS" in these voltage readings
...especially "over time"
...but, I'll continue monitoring them 

The first ~3 minutes, of this video, shows using the Cell Checkers to "test" the voltage levels, of these (2) modules.


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## Functional Artist (Aug 8, 2016)

*End of the year Update*

I took another voltage reading of my battery modules on 12/31/22








The "slightly puffed" module seems to be holding pretty steady at 49.32V








...& the "fresh" module also, seem to be holding pretty steady at 49.56V


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