# First Post: Question about Chevy Volt battery



## Yabert (Feb 7, 2010)

Welcome. You are right about nissan VS chevy Volt cells except on one thing.
For 12 cells in serie (45V nominal) you only need one 300$ Zeva BMS16 for chevy Volt or Nissan cells.
It's what I've done in my smart, but I've also do this for solar system.
In my Smart I linked* the cells tabs between parallele cells**, but for a 48V solar battery, I linked the cells by the BMS connector (orange on pic). So, two cells link togeter can be consider as one cell.
13 small wires and two large conductors at each end of the battery. This work well if you are sure than no more than 1A will ever flow in those small wires who is generally the case with high quality LG chem cells of the Volt battery.


*Weld with a TIG, but it's too complex and not need for a simple solar battery.
** same exact voltage before connecting them.


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## Murphy (Aug 20, 2019)

Yabert said:


> Welcome. You are right about nissan VS chevy Volt cells except on one thing.
> For 12 cells in serie (45V nominal) you only need one 300$ Zeva BMS16 for chevy Volt or Nissan cells.
> It's what I've done in my smart, but I've also do this for solar system.
> In my Smart I linked* the cells tabs between parallele cells**, but for a 48V solar battery, I linked the cells by the BMS connector (orange on pic). So, two cells link togeter can be consider as one cell.
> ...



I'm not getting this. How are you using a 16 cell bms to balance 24 cells? on two different packs?


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## Immo1282 (Jul 12, 2019)

If you connect two cells in parallel - a BMS will just treat it as one, larger cell instead of two distinct cells. It's pretty much accepted to be fine to do this for cells of the same origin and past cycles etc.


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## Murphy (Aug 20, 2019)

Immo1282 said:


> If you connect two cells in parallel - a BMS will just treat it as one, larger cell instead of two distinct cells. It's pretty much accepted to be fine to do this for cells of the same origin and past cycles etc.



If I have six or seven of the 48v packs, that still works out to over $900.. and I'd still need a bms for the 7th pack.


Is there a cheaper alternative? The way this is looking, I might have to pass on the volt pack and find cells I can parallel and then series.


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## Duncan (Dec 8, 2008)

You can simply parallel the volt modules AND the cells inside them

The connector on the top of each module has wires to each cell (actually there are already some in parallel) 

You just connect the modules using the nice bolt on connections and use the connectors to parallel up the cells

From memory a 48 volt module is actually 12S x 3P (internally connected)

So four of them would end up 12S x 12P - and would need one 12S BMS


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## Yabert (Feb 7, 2010)

Exactly as Duncan describe. 12S + XXP
In the case of a 16 kWh Volt pack that mean 8 pack of 45V and so 12S 24P (24 cells in paralel or differently, 8 groupe of 3 cells in parallel). 45V 360Ah instead of 360V 45Ah 
At the end, only one 12S BMS


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## swoozle (Nov 13, 2011)

If you are willing to play with CAN, you can use the stock Volt BMS slaves to monitor and balance your pack even if configured as 45V in parallel. TomDB's SimpBMS might even do it. 
The one caveat is that each slave must be fully populated with modules to work correctly. If you are using the whole pack then you have no problem.


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## Ocean (Dec 20, 2016)

I purchased several Chevy Volt complete packs (16kwH, like what you are considering) - mainly for use in my Bradley EV project, and also a couple for a Chevy S10 Conversion.

I ended up with extra 12s units (2kWh) and 6s units (1kWh) and I am using them both in my Off Grid solar energy systems - the 12s units in parallel (3 of them for 6kWh's in a 48v system) and the 6s units also in parallel in a different system (24v system)

I do not have any BMS. I have noticed that they actually keep within 0.01 or 0.02 voltage pretty darn good.

However, if any of them needed adjustment, I would simply use a power resister to drain down a little voltage, or use a small power supply to lift it up, on individual cells.

I have not really needed to do that so far, and I am running off grid with deep cycles almost every day.

I agree it's a sacrifice that you have to run a lower voltage and therefore higher amperage.

Also, in order to realize the full potential of your Chevy Volt batteries as a 12s unit, you must be able to program your inverted to have a LBCO of 36 - 38 volts (3v x 12s = 36 volts which is a safe / conservative LV for the Chevy Volt modules). Most inverters only go down to 42v. You might check yours, or you may end up with great batteries but you can use only half their potential.

On the other hand, if you look on Ebay for Tesla batteries, you may come across some 7S Tesla modules, which were designed by Tesla for Mercedes for their B-Class Hybrid. Those modules are awesome, because they have a high voltage of 29.4 and a low voltage of 21. I use them in my 24v system and they are a perfect drop in. I bulk to 29.2 and float at 28.8. They perform excellent. They are 3kWh each. If you put two in series they would be a perfect fit for any standard 48v system. Or, of course, 2p x 2s for 12kWh's. A bit more expensive than the Volt's, but still pretty good.

Both the Chevy's and the Tesla's are awesome. In fact I find the Chevy's to be a little more even with themselves as far as cell balance.... but I haven't balanced them (the Tesla's) yet because they are still within .02 or .03 of each other and I never really push them to their limits.

If you are willing to manually keep and eye and balance your batteries once in a while, they will serve you amazing. Virtually no sag starting motors - and I run a 1.5hp deep well pump that pulls almost 3kw continuous.

I actually had a situation with one of the 12s Volt modules where one cell was very low - about 2.5 volts. I let it sit that way for a couple years. Finally I decided to just try and balance it. I put a 4v DC supply on it, and watched the voltage slowly go up. Eventually I balanced that cell with the others. I then tested the unit with a couple cycles to see if the cell would maintain balance with the rest. It did. I finally integrated it into my 48v system and so far so good. Been a few months now... crossing my fingers maybe I will go check one of these days soon... But I think something must have fallen across the cell - maybe a stick or twig or something - and slowly drained it down - every other cell in the pack is good. They hold a balance really well IMO... and dang only 30k on that car! I would grab it up if I could use it! Again, will your inverter go that low? Down to 36 or 38v LBCO?


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## vauron (Sep 25, 2016)

Thanks, swoozle, you've given me new hope!


I have a complete Gen1 that I have yet to take apart. I want to use the whole thing to power my electrified Delorean. As the motors are in-wheel, the entire space taken up by the original PRV V6 engine is available for the battery. After relocating the front third of the battery to the car's frunk (which will no longer have the gas tank inside the front wishbone), by pure luck the T-shaped remainder fits perfectly in the lower half of the engine bay, leaving enough space above the battery to use the Delorean as a pickup or whatever.


It is easy enough to connect the wiring and cooling of the front third in the frunk back to the rest of the battery in the rear. So the battery as a whole should therefore have no idea what hit it, either electrically or cooling-wise.


So if I understand you I should be able to use the Gen1's original BMS without modification, right?


That would be a fabulous labor-saver.


Here's the skateboard half of the Delorean in my driveway.







And here it is in my garage.







The Volt battery is between the body (background) and the skateboard (foreground). Let me know if these two images don't show up.


So can I do this, easily?


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## Joshie225 (Jul 31, 2019)

I'm doing the same thing as Ocean, running without active BMS and manual balancing. I monitor the cells with a Tenergy 5-in-1 Battery Meter 

If I had a 48V system I would be using Gen 2 Leaf modules. 

I have a 24V nominal system and am running 7S as 6S drops the voltage out of my inverter/charger's operating range. While the Volt pack you've found is a great value the welded construction and 12S arrangement may be a deal breaker if your inverter won't accept the 12S voltage range. I chose Ford C-Max Energi cells so that I could rearrange them into 7S connection which is not so easy with Leaf modules which are of course 2 cells each and 8S again takes me out of my inverter's happy place. There are 84 cells in the 7.6kW C-Max Energi pack. I put 14 cells from the pack in a 24V eGo scooter and the remaining 70 cells (6.3kW) in the home backup power system.


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## Murphy (Aug 20, 2019)

Ocean said:


> I purchased several Chevy Volt complete packs (16kwH, like what you are considering) - mainly for use in my Bradley EV project, and also a couple for a Chevy S10 Conversion.
> 
> I ended up with extra 12s units (2kWh) and 6s units (1kWh) and I am using them both in my Off Grid solar energy systems - the 12s units in parallel (3 of them for 6kWh's in a 48v system) and the 6s units also in parallel in a different system (24v system)
> 
> ...



My inverter only goes down to 42 volts but I think I'm going to pass on the Chevy battery and hold out for a Nissan Leaf or something similar. I do not like the idea of running an 8000 watt inverter that cost $4300 at low voltage.. Going to opt for something I can configure into 13s or 14s and a configuration that only needs one BMS.


Thanks for your detailed experience, that helped a lot..


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## Ocean (Dec 20, 2016)

Sounds like a good plan! Again, have a look on ebay at those Mercedes B-Class Tesla Batteries.... 7S units 3kWh each. These are a perfect drop in for 24v systems and 2 of them in series would be a perfect drop in for 48v systems - giving a low of 42v (14s x 3v) so two of them would give you 6kWh and you could double that with two strings in parallel.... good luck!


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## Off the grid (Feb 10, 2017)

Murphy said:


> Ocean said:
> 
> 
> > I purchased several Chevy Volt complete packs (16kwH, like what you are considering) - mainly for use in my Bradley EV project, and also a couple for a Chevy S10 Conversion.
> ...



I have 2 radian inverters and 14 model s modules 
The inverter turns off at 36v i have the gen come on at 38v. No problem


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## jlanman (Dec 23, 2012)

I live in Florida and have a situation similar to yours. I looked into using batteries in my converted Ford Ranger for backup when the grid goes down. I backed away due to cost and complexity. I elected to continue to use my gasoline generator. (The energy density of fossil fuels is hard to beat.) Based on your stated usage of1000 watts it wouldn't take much of a generator. I believe you might find one for about the same cost as you're considering paying for batteries. It would also eliminate the risk of depleting the batteries before the grid is restored.


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## Murphy (Aug 20, 2019)

Off the grid said:


> I have 2 radian inverters and 14 model s modules
> The inverter turns off at 36v i have the gen come on at 38v. No problem


 The specs in my Radian 8048 say it shuts down at 42 volts. How do you come all the way down to 36 volts and is that even wise to do? That's a lot of current and heat to be generated.


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## Murphy (Aug 20, 2019)

jlanman said:


> I live in Florida and have a situation similar to yours. I looked into using batteries in my converted Ford Ranger for backup when the grid goes down. I backed away due to cost and complexity. I elected to continue to use my gasoline generator. (The energy density of fossil fuels is hard to beat.) Based on your stated usage of1000 watts it wouldn't take much of a generator. I believe you might find one for about the same cost as you're considering paying for batteries. It would also eliminate the risk of depleting the batteries before the grid is restored.


 1000 watts is just average, not actual use. While the home generally sucks about 1000 watts, it will jump up when freezers turn on or the water pump runs or the sump pump runs. These are short duration spikes, but they will over-load anything not capable of 4000+ watts. 

And I haven't even gotten to talking about the mig welder, plasma cutter or air compressor yet. These loads draw 4000, 5000, and even 6000 watts or more on their own, albeit for somewhat short duration as well. 



We do run a generator for normal grid down events which happen three or four times a year here. My 5000 watt Coleman is hooked to a natural gas line. But I hate having to listen to it. 



Most of what I'm doing is in case the grid goes down for an extended period. Terrorist attack, etc. 



I bought the Chevy Volt battery today for $1350 Its in the back of my truck. This doesn't invalidate my desire to purchase more batteries, but it will get me going somewhat. Now I need to figure out if there is a way to turn the 12s modules into 14s modules. I have copper and can fabricate just about anything. I'm wondering if I can rob the 6s modules of a couple plates each and tack them to the end of the 12s modules.


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## Ocean (Dec 20, 2016)

Murphy said:


> 1000 watts is just average, not actual use. While the home generally sucks about 1000 watts, it will jump up when freezers turn on or the water pump runs or the sump pump runs. These are short duration spikes, but they will over-load anything not capable of 4000+ watts.
> 
> And I haven't even gotten to talking about the mig welder, plasma cutter or air compressor yet. These loads draw 4000, 5000, and even 6000 watts or more on their own, albeit for somewhat short duration as well.
> 
> ...


That VOLT battery for $1350 was a great deal.

I don't know anything about the Radian inverters. But, if Off_The-Grid says his Radian inverters shut down at 36v, then most likely yours can too. Specs often tell you the range as Manufacturer Default. However if you look closely, the actual range may be higher. Go into you Low Battery Cut Off (LBCO) setting and see how low you can adjust it.

36v for a 12s Lithium battery is fine because thats 3v per cell. If you look into the chemistry specs you will find the Low value to be about 2.5v per cell and the high value to be about 4.2 volts per cell. Although there is a quick decline once you get down to about 3v, so having a 3v per cell low is pretty safe.

Of course you are running slightly more amps because you are running in a lower voltage range. But, consider that the Lithiums have virtually no voltage sag under heavy load (unlike Lead Acid which has major sag). For example, I have a mere 2kWh 6s Volt Unit running my 24v system, and I can start my 1hp table saw or my mid-size air compressor and watch the volts go down... maybe 0.4 volts. Hardly any sag and it's only barely a 100amp hour battery.

So they will hold their voltage very well under load. This means less intense surges through your inverter, and perhaps the overall average amperage won't be much different comparing for example an 8kWh Lithium pack running 50v @full vs a 8kWh LA pack running 58.4v @full because under heavy load those LA's will sag major where the Lithium's will not.

Anyways, before you go hacking those beautiful VOLT modules apart (which is probably impossible to do neatly - you will see what I mean once you look closely how they are assembled), look closely at your Radian settings to see if you can bring down the LBCO down to 36 volts. Even at 42 volts LBCO you still have great capacity from a large pack of Lithiums.

Also, be aware that those VOLT packs are under compression. And I mean major compression. If you un-bolt the end-caps, the packs will expand dramatically. You must be prepared for it. the tops of the packs are banded together. If you remove the band, the plastic top will be the only thing holding the module together, and it will eventually break. If you want to re-configure the packs physically, you will need Metric Threaded Rod (M6 I believe).

I have done this operation of physically re-configuring the packs and it is a super pain in the ass. But it is indeed doable. Huge (LONG) clamps really help - like wood working clamps. Also threaded rod and strong steel plates like 1/8 x 3/4 x 7 or 8" with a hole on each end. Turnbuckles.

I truly recommend leaving them as they are - just line them up so you can connect them electrically. Parallel each 12s unit. Run a jumper for the two separate 6s units to make another 12S unit and add it to the parallel setup.

OR, sell me the 6s units!!! haha. But then you would be un-bolting the packs and again I don't recommend it unless you really need to. Major expansion.

I hope you find a setting on your Radian to bring down the LBCO that's really the best solution in my humble opinion.

Awesome Find! Have Fun with those beauties!


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## swoozle (Nov 13, 2011)

Ocean said:


> That VOLT battery for $1350 was a great deal.
> 
> ...
> Also, be aware that those VOLT packs are under compression. And I mean major compression. If you un-bolt the end-caps, the packs will expand dramatically. You must be prepared for it. the tops of the packs are banded together. If you remove the band, the plastic top will be the only thing holding the module together, and it will eventually break. If you want to re-configure the packs physically, you will need Metric Threaded Rod (M6 I believe).
> ...


The only compression they are under by the through-bolts is to compress the seals present at each liquid coolant channel running along the sides of the cell modules. Unbolting those to separate the modules and rebolting them is really not a big deal. Rebolting can be done without clamps by using sufficiently long threaded rod and then trimming to length after tightening the nuts down (been there, done that).
The bands at the top really don't do much. They can almost be slid off by hand. I've been running without those with no problem.

Breaking down the modules to the cell level is a whole other story, yes.


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## Ocean (Dec 20, 2016)

swoozle said:


> The only compression they are under by the through-bolts is to compress the seals present at each liquid coolant channel running along the sides of the cell modules. Unbolting those to separate the modules and rebolting them is really not a big deal. Rebolting can be done without clamps by using sufficiently long threaded rod and then trimming to length after tightening the nuts down (been there, done that).
> The bands at the top really don't do much. They can almost be slid off by hand. I've been running without those with no problem.
> 
> Breaking down the modules to the cell level is a whole other story, yes.


Ok... maybe so. I've seen a single 2kWh 12s unit with no banding break at the top, where plastic holds it together. The pouch cells starting to separate at the end. I compressed it back and yes, no problem. But I didn't like seeing it press it self apart. Keeping them compressed like they are designed seems right to me.


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## Duncan (Dec 8, 2008)

There is no real load in the bands - you can slide them off with your fingers - make new ones the required length and slide them back on

The threaded rods are easy as well -


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## Murphy (Aug 20, 2019)

There is a video on youtube called "Chevy Volt Battery Deep Dive" that is incredibly informative.

Here it is:
https://www.youtube.com/watch?v=eWYtq0hxhQg


I just reviewed my Radian's specs again and the other poster is correct, it goes down to 36 volts. I read the chart wrong, the 42 volts was the default setting.

Good to know, now I can leave the 12s packs as they are.


Now back to figuring out a BMS system. Going to have to purchase 7 of them and don't want to spend $4000 on it. 



Suggestions? 

TechDirectClub.com sells BMS controllers for their Nissan Leaf packs. I called them up and they gave me the model number as a 14s SmartBMS JBD-SP15S001. 
When searching for that, I found the website that sells the 12s SmartBMS in various 20a,40a, 60a, and 120 amp configurations. 



Since the Radian can pull 12,000 watts (peak), that 250 amps divided by 7 packs = 36 amps per pack. So I'm thinking a 60amp BMS would do the job well.

I know almost nothing about BMS systems.. Here is what I "think" I know.
1) They make sure all series cells stay balanced by either adding extra charge to one cell, or bleeding off energy from an over-charged cell.


2) They can shut off power from that pack if certain conditions are met like High Voltage, Low Voltage, or High Current or various other undesirable events.


3) Not all BMS's can do what other BMS's can do. This is the part that worries me. I need something appropriate (7 of them) that can provide maximum safety and shut down the pack if something goes wrong.


4) The BMS has to be sized for the AH rating of the pack. The balancing current of the BMS has to fall within a reasonable range of the capacity of the pack. A BMS board that is designed to balance some 18650 cells is not going to be big enough to properly balance a Chevy Volt cell. The Chevy Volt cell has too much energy and a small BMS won't be able to process enough juice to make any real difference.


5) I want something that I can look at with a computer or a stand alone display screen and I DO NOT want to have to use a cell phone, blue tooth, or wifi. I want something that has a hard wire and can be viewed on any PC. 




Point me in the right direction please. You guys know a lot more about this stuff than I do.

I have a Hoffman steel cabinet (NEMA 4x) this battery is going into. The cabinet is 4 feet tall, 20 inches deep and 4 feet wide. Its brand new and its a beast. I paid $50 for it. ( LOL )


Thanks for all the help!


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## Duncan (Dec 8, 2008)

You only need ONE BMS is you paralel up at the cell level

Why do you need a BMS - in my reading about peoples builds I would say that having a BMS has caused more problems than not having a BMS

As far as I can see lithium cells especially the high quality EV ones don't go out of balance 
The "new" cells however do have a high failure rate - about 3% and a "sudden death rate"
EV ones appear to be a lot better 
I have never ever heard of anybody managing to "save" a cell with a BMS - but a BMS will tell you if a cell has failed BEFORE you overcharge it

On that point I have the world's simplest BMS

http://www.evdl.org/pages/battbridge.html

This will tell me that the two halves of my battery are out of balance - which means I need to get the voltmeter out

I am more than slightly abusing my Volt battery (1200 amps) - and I do a check every six months - so far all within 14mV

_Hi Guys
I have been driving with the Volt battery for about 5 months - including some driving on the track
I don't have a BMS - but I do have a Batt Bridge - everything looks OK

So time for my manual battery check
I drove until I got the battery down to my minimum voltage -295v 
Then started disassembling 
( I have to take a few bits out of the way to get to all my cells)
Friday Voltage - 295v (measured by CA)
Saturday - voltage had gone up to 296.9v (measured by CA)

Voltmeter on both sides of pack - both 149.7v (added together 299.4v)

Using my Celllog 8M I checked all of the cells 
max - 3.548v
min - 3.536v
range 12mv
Looking good!

So I charged it
341.6v on the CA
Voltmeter on both sides of pack - both 172.1v - 172.2v (added together 344.3v)

Using my Celllog 8M I checked all of the cells 
max - 4.078v
min - 4.064v
range 14mv

So all looking good!
_


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## Murphy (Aug 20, 2019)

Duncan said:


> You only need ONE BMS is you paralel up at the cell level
> 
> Why do you need a BMS - in my reading about peoples builds I would say that having a BMS has caused more problems than not having a BMS



Its a Chevy Volt battery, you can't take them apart to parallel the cells like you can with a Nissan Leaf battery. 
I understand its better to go with a parallel series config, but the chevy volt pack only allows a series then parallel setup.



Why a BMS? I'm investigating that now, but the pack has its own BMS already built into it so it must be important right?


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## Ocean (Dec 20, 2016)

Murphy said:


> Its a Chevy Volt battery, you can't take them apart to parallel the cells like you can with a Nissan Leaf battery.
> I understand its better to go with a parallel series config, but the chevy volt pack only allows a series then parallel setup.
> 
> 
> ...


Well, I could think that any car manufacturer would build a BMS into their system if they are bothering to build an electric car.... not only to balance cells but to alert the computer if any cell goes bad. They need to get 100k miles out of that battery, with heavy charging and discharging.... so a BMS becomes more important under those conditions I would think... also it's a liability issue if a cell goes bad and / or catches fire while charging etc... so monitoring those cells in a regular "plug and play" car where the user has no access to the battery becomes much more important.

But considering that a Volt battery used as a house battery will never see the kind of loading and quick charging conditions that it sees in a car, as it was designed for - I think it's a pretty safe bet that any imbalance would occur very slowly, and if you are willing to check their cell voltages once in a while, you will be fine....

Of course it's your game and you gotta do what you feel is best!


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## jlanman (Dec 23, 2012)

Murphy said:


> 1000 watts is just average, not actual use. While the home generally sucks about 1000 watts, it will jump up when freezers turn on or the water pump runs or the sump pump runs. These are short duration spikes, but they will over-load anything not capable of 4000+ watts.
> 
> And I haven't even gotten to talking about the mig welder, plasma cutter or air compressor yet. These loads draw 4000, 5000, and even 6000 watts or more on their own, albeit for somewhat short duration as well.
> 
> ...


Thanks for the clarification. I was considering using my truck batteries for the same reason(s). It got complex and costly because my solar inverters are not suitable for charging batteries and I wanted to be able to use the truck when not connected for backup. I probably need to go back to this; as, the world seems to be getting more risky. Fossil fuel is only a good backup alternative, if you can get it.


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## Murphy (Aug 20, 2019)

jlanman said:


> Thanks for the clarification. I was considering using my truck batteries for the same reason(s). It got complex and costly because my solar inverters are not suitable for charging batteries and I wanted to be able to use the truck when not connected for backup. I probably need to go back to this; as, the world seems to be getting more risky. Fossil fuel is only a good backup alternative, if you can get it.


SolarEdge makes an inverter called a "StoreEdge" that integrates the solar panels to the grid and can charge a 350 to 500 volt lithium ion storage battery. They built it to be compatible with the LG Revnu 10kw lithium system. The inverter seamlessly switches from grid power to battery backup, you won't even see your computer blink as it does it in like 20ms. 

Its like $2700 for the inverter system and you can stack the batteries for even more juice.

I have to wonder why they say "Only compatible with LG Revnu"... the Chevy Volt battery floats around the 350 to 400 volt mark so it falls within the range listed in the StoreEdge inverter. The Renvu battery says 400 volts. Heck, I'm wondering if it would even be necessary to open the battery case or just hook up to the terminals? 
Being in Michigan, I got to thinking, I could install the battery(s) under the solar array then run a 5 foot deep trench 75 feet and lay in some pex tubing. Hook that to the batteries, run antifreeze through them, and the earth would keep my batteries at 50 degrees year round. It would warm them in the freezing winter and cool them in the hot summer. 

My current solar system uses a SMA Sunnyboy inverter and it has a feature called "Secure Power". When the grid goes down and it stops making power (anti-islanding), it has a switch I can flip to activate a separate circuit that will provide 2000 watts at 120volts to an isolated household receptacle. I plan on using that 2000 watts to charge my Chevy Volt battery using a battery charger that is compatible with the 12s setup. I'm looking at the Fullriver _FR1_-_RT_ Battery _Charger. 
_


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## Duncan (Dec 8, 2008)

Murphy said:


> Its a Chevy Volt battery, you can't take them apart to parallel the cells like you can with a Nissan Leaf battery.
> I understand its better to go with a parallel series config, but the chevy volt pack only allows a series then parallel setup.
> 
> Why a BMS? I'm investigating that now, but the pack has its own BMS already built into it so it must be important right?


WRONG
You can incredibly EASILY paralel up Chevy Volt modules 
Each module has a plug for the BMS - this plug has a wire going to each of the cells (actually to each already paralleled up set of three) 

A 12S module has 36 cells

If you are paralleling up a series of 12S modules just connect these wires together - and there you are

Sequence
(1) get each module to the same voltage
(2) connect the modules together - so they are EXACTLY the same voltage
(3) connect the BMS wires together 

As far as the "the OEM's do it so it must be important" - this is very true - but their requirements are more stringent than mine or yours

They need 200,000 miles with almost no failures when used in a car by average drivers

You are going to be much more gentle with the cells and you can do what I do

The Batt Bridge will tell you if you have lost a cell


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## Murphy (Aug 20, 2019)

Duncan said:


> WRONG
> You can incredibly EASILY paralel up Chevy Volt modules
> Each module has a plug for the BMS - this plug has a wire going to each of the cells (actually to each already paralleled up set of three)
> 
> ...



The statement wasn't that the cells couldn't be paralleled for the BMS, it was that the cells themselves couldn't be reconfigured in a parallel config. 

The cell tabs are welded so you can't (easily) take them apart and make a 3.7 volt battery with 200AH of capacity. 

The 2014 Chevy Volt is a 3p96s system that breaks down into six or seven 3p12s modules with a nominal voltage of 44.4 volts. 

What I'd like to do is to reconfigure it into 3.7 volt modules with as much amp/hrs as I can get by paralleling the cells.


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## Duncan (Dec 8, 2008)

The paralleling connections only have to take the differences as in milliamps or less - the main current goes through the main connectors


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## ga2500ev2017 (Jun 12, 2017)

Murphy said:


> Its a Chevy Volt battery, you can't take them apart to parallel the cells like you can with a Nissan Leaf battery.
> I understand its better to go with a parallel series config, but the chevy volt pack only allows a series then parallel setup.


That assertion isn't correct. The BMS connector on the top of Volt module gives you access to the individual cells without taking anything apart. The OEM BMS has to have access to the individual cells of the modules to balance them.

You can take as many 12S Volt modules as you wish, parallel them at the power terminals, then connect balance connectors between each cells of the module using the BMS connector. Then using an appropriate single 12S BMS to manage the entire battery pack. Once the balance leads are in place, each of the cells will self balance so that all the paralleled cells will function as a single cell.

ga2500ev


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## Murphy (Aug 20, 2019)

ga2500ev2017 said:


> That assertion isn't correct. The BMS connector on the top of Volt module gives you access to the individual cells without taking anything apart. The OEM BMS has to have access to the individual cells of the modules to balance them.
> 
> You can take as many 12S Volt modules as you wish, parallel them at the power terminals, then connect balance connectors between each cells of the module using the BMS connector. Then using an appropriate single 12S BMS to manage the entire battery pack. Once the balance leads are in place, each of the cells will self balance so that all the paralleled cells will function as a single cell.
> 
> ga2500ev


OK, I don't think I"m confused, but maybe I am.


The 2014 Chevy Volt has 288 cells organized into a 3p96s configuration. There are 96 plates in series and each plate has 3 cells in parallel. 



What I want to do is:
Option 1: Add a plate (or two) to the 12s module to make it a 13s or 14s module, or


Option 2: Just take them all apart and reconfigure them into 13 or 14 modules with a 18p1s configuration. 


This is easy to do with the Nissan Leaf packs because they have screw terminals. But the Chevy packs are all welded funky with a spot welder. 

I'm going to be purchasing two SMA Sunny Island 6048 inverters and they have a maximum voltage range of 41 to 63 volts. 

I already have a Radian 8048 as well but I want to keep it stored as a backup unit.

Since my solar array already has an SMA Sunny Boy inverter, the Sunny Island inverters will play well with it. The Sunny Island units are designed specifically to match up. 


You guys are a wealth of information. Thanks!


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## Murphy (Aug 20, 2019)

Yabert said:


> Welcome. You are right about nissan VS chevy Volt cells except on one thing.
> For 12 cells in serie (45V nominal) you only need one 300$ Zeva BMS16 for chevy Volt or Nissan cells.
> It's what I've done in my smart, but I've also do this for solar system.
> In my Smart I linked* the cells tabs between parallele cells**, but for a 48V solar battery, I linked the cells by the BMS connector (orange on pic). So, two cells link togeter can be consider as one cell.
> ...


So the more I research this, the more I find that your technique for setting up your bms is really nice. A very clean install. 



So when looking at your picture, your Zeva BMS has a resistor board connected to the Zeva BMS input. What is that board? Did you fabricate that custom or have it made or what?


Thanks!


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## WattsUpDoc (Sep 25, 2019)

Murphy said:


> OK, I don't think I"m confused, but maybe I am.
> 
> 
> The 2014 Chevy Volt has 288 cells organized into a 3p96s configuration. There are 96 plates in series and each plate has 3 cells in parallel.
> ...


Hi Murphy,

This thread has gone a bit stale, but I'm working on a Chevy Volt project as well, and working on balancing modules in parallel, so would like to pick it up again if anyone is still interested.

It looks to me like the 12S modules would be perfect for the Sunny 6048 inverters, as they would run about 45V nominal. Keep the cells above 3.4V, and you'll be above the 41V minimum. That corresponds to 326V for the full series pack in it's original configuration. Looking at the discharge curve when running at 10kW, at 3.4V/cell you've pulled out most of the energy, reached the knee of the curve, and wouldn't want to run lower anyway.

https://www.energy.gov/sites/prod/files/2015/02/f19/batteryVolt4313.pdf

So I would put the 12S packs in parallel, connect the individual cells together through the BMS connector (as Yabert has shown), and run one BMS on the connected cells.

My only concern on this design is running too much current through the relatively small BMS wires, in the case where a cell in one pack is particularly low or high. We may want something like Yabert's PCB, but with fuses instead of resistors for safety.


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## vauron (Sep 25, 2016)

I don't right now have a specific question about the Gen1 Chevy Volt battery. However for those interested in it, I have one in my garage that I'm about to put into my Delorean (VIN the first prime after 6666), which is now down to just a frame with no engine, transaxle, or gas tank. (The stainless steel + fiberglass body is strung up elsewhere in my garage waiting to come back down when the frame is ready for it.) This entails the following steps.

1. The cells are down to 3.45V, so 330V total. Beore I start chopping up the battery (see below) I'm planning to charge it very gently to 384V with 8 Cisco 48VDC 0.38A adaptors that I got on eBay for $39 the lot (actually 11 of them, so maybe I'll shoot for the full 400V). Later on I can figure out how to charge them faster but this is fine for the time being. I'm hoping that each of the four modules has a self-contained BMS that will keep each module nicely balanced and that I only need to monitor the modules' total voltages and not their individual cells.

2. It would be great if the whole battery would fit where the PRV V6 engine and transaxle went, but it doesn't quite fit. So I'm going to cut the front "stem" of the T-shape at the natural cut point and put the front module where the gas tank used to sit. The truncated T, consisting of two modules at the back and one module as the rear part of the "stem", turns out to fit very neatly in the engine bay. I just have to design some angle irons that will support the battery so it doesn't flex too much. My friend Michael McClure who used to race Alfa Romeos and own Ferraris is helping me on this.

3. I have to figure out the ideal climate control for the battery. Supposedly it likes a constant 70 °F for maximum life, but for now maybe it will be ok to subject it to a wider range. The Delorean has two radiators, one for the engine and one for the A/C, I need to decide which one to use to keep the battery cool. For the time being I don't care about protecting the battery against cold weather, if necessary I can warm it up in the garage somehow as needed. 

4. A shipment of two in-wheel motors, inverters, and "powerbrain" will arrive shortly from Elaphe Propulsion, maybe even tomorrow if customs clears that fast. Continuous power per motor is 50 kW, peak is 75 kW which adds up to 200 HP. This is an improvement over the 140 HP I was getting from the Peugeot-Renault-Volvo V6 engine.


5. Longer term I plan to add a supercapacitor-based KERS and a ZEF (zero-emission fuel, TBD) range extender. Also whatever aftermarket driver assistance packages are available (MobileEye?). Not sure if the Delorean can accommodate airbags.


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## Duncan (Dec 8, 2008)

My prediction is that you are going to be incredibly disappointed and that your car will be unable to climb a curb 

I hope you prove me wrong


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## brian_ (Feb 7, 2017)

vauron said:


> I don't right now have a specific question about the Gen1 Chevy Volt battery. However for those interested in it, I have one in my garage that I'm about to put into my Delorean...


This Delorean project sounds like it could be the subject of an extensive and lively discussion... which would be a huge sidetrack to this thread. How about starting a separate thread in the _All EV Conversions and Builds_ section?


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## vauron (Sep 25, 2016)

Duncan said:


> My prediction is that you are going to be incredibly disappointed and that your car will be unable to climb a curb.


My bad, I neglected to consider curb-climbing as a use case. 

But how come? Too few amps available from the battery (internal resistance too high?), something about the two motors, something else?


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## brian_ (Feb 7, 2017)

vauron said:


> But how come? Too few amps available from the battery (internal resistance too high?), something about the two motors, something else?


This is now being discussed in its own thread: _*Yet another Delorean conversion*_


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