# SE/TS charging and general handling questions



## JRP3 (Mar 7, 2008)

As some of us are getting close to having our SE/TS cells in hand I thought it might be good to get some general cell knowledge stuff cleared up, at least for me.
1. With the TS cells there is a recommendation to initially charge each cell to 4.25 volts to "set" the chemistry and activate the cells. Is the same true of the SE cells which list a 3.6 max voltage? From what I've read current doesn't matter as long as it's under the maximum safe limit.

2. I've heard that fully charged cells should not be unstrapped as they can swell and separate. Is this true, and is there a time limit, i.e., moving cells around and then strapping them back down as opposed to letting a charged cell just sit on the shelf unstrapped?

3. Are there torque numbers for the terminal bolts?


That's all I've got for the moment.


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## Technologic (Jul 20, 2008)

JRP3 said:


> As some of us are getting close to having our SE/TS cells in hand I thought it might be good to get some general cell knowledge stuff cleared up, at least for me.
> 1. With the TS cells there is a recommendation to initially charge each cell to 4.25 volts to "set" the chemistry and activate the cells. Is the same true of the SE cells which list a 3.6 max voltage? From what I've read current doesn't matter as long as it's under the maximum safe limit.


Not that I'm aware of JRP3. Seems like 4v is ok for the initial charge though



> 2. I've heard that fully charged cells should not be unstrapped as they can swell and separate. Is this true, and is there a time limit, i.e., moving cells around and then strapping them back down as opposed to letting a charged cell just sit on the shelf unstrapped?


They can swell a tiny amount from my experience with the SE... I don't know about a time limit, but I'd say 1-2 weeks I started noticing a tiny bit of swelling



> 3. Are there torque numbers for the terminal bolts?


No but I wouldn't go over 60 lbs (probably much less) The posts on the SE are meant to screw into the battery, you don't use the nuts provided to attach the terminals usually.


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## dimitri (May 16, 2008)

> 1. With the TS cells there is a recommendation to initially charge each cell to 4.25 volts to "set" the chemistry and activate the cells. Is the same true of the SE cells which list a 3.6 max voltage? From what I've read current doesn't matter as long as it's under the maximum safe limit.


No such thing as "activate". They come about half charged, so you just charge them up to whatever HVC your charger is set for and that's it.
DO NOT CHARGE OVER 4.0V , TRUST ME  
After 3.8V voltage rises super fast, especially if your charger is still at high current at the time, within a minute you can go from 3.9 to 4.5 and it will swell a little.



> 2. I've heard that fully charged cells should not be unstrapped as they can swell and separate. Is this true, and is there a time limit, i.e., moving cells around and then strapping them back down as opposed to letting a charged cell just sit on the shelf unstrapped?


While it may or may not be true, I would not charge them until I get them all installed first, then do a first charge. What's the point of connecting all cells and charging them if you have to take them apart again later to install? They can sit for months in the state they were shipped, no need to charge them right away.
I had cells unstrapped for few days while working on battery trays, no swelling.




> 3. Are there torque numbers for the terminal bolts?


They come with a book, it should be in there, but I don't have mine handy. I just gently used my impact wrench, stopping after a few "knocks" ( scientific terms  ).

Some advise from personal experience:
- realize that each cell has a tad different capacity and maybe a tad different SOC at first, so first cell will always reach HVC sooner than others. When that happens your charger better be at low current and you better have shunts/balancers installed. If not, shutoff your charger ASAP...

- always use lock washers to prevent post bolts from coming loose


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## JRP3 (Mar 7, 2008)

dimitri said:


> No such thing as "activate". They come about half charged, so you just charge them up to whatever HVC your charger is set for and that's it.
> DO NOT CHARGE OVER 4.0V , TRUST ME


This is a direct contradiction to what I've read elsewhere, what other's have claimed the instructions specify, and what Dave Kois from evcomponents/poweredby dc, is saying. Specifically, initially charge the cell to 4.25. Some have connected all cells in parallel and used a power supply set to 4.2 volts to do this initial charge.
Check out this EVDL post on the subject:
http://www.evdl.org/archive/index.html#nabble-to24179211
So there is some contradicting information out there.


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## dimitri (May 16, 2008)

JRP3 said:


> This is a direct contradiction to what I've read elsewhere, what other's have claimed the instructions specify, and what Dave Kois from evcomponents/poweredby dc, is saying. Specifically, initially charge the cell to 4.25. Some have connected all cells in parallel and used a power supply set to 4.2 volts to do this initial charge.
> Check out this EVDL post on the subject:
> http://www.evdl.org/archive/index.html#nabble-to24179211
> So there is some contradicting information out there.


The only way to explain this practice is "initial balancing" , the goal of which is to make sure all cells are on same SOC level, but voltage level itself has no significance other than being "max safe voltage". You will get same results by charging all cells to 3.8 or 3.9 or 4.0 or 4.1 .... you get my point 

I personally considered this parallel initial charge, but IMHO its not practical unless you have a 4V 20-100 Amp power supply. Charging 40+ cells in parallel with less than 20 amps is an excersise in futility  , it would take too damn long.... didn't you wait enough to get these cells already ? 

I probably read as much as you before spending this kind of money, and I am not aware of any technical or physical reason for "activation charge".

OTOH, I read quite a bit of bullshit typically associated with new and expensive technology, which usually comes with a sense of mystery an awe 

Not saying I'm an expert or anything, but my cells never seen over 3.8V and they work just fine, except one cell got to 4.25V during initial charge because I was stupid enough to risk initial charge without shunts/balancers, and that cell is a little swollen now, although still works fine, but I suspect this will be the first cell I will eventually need to replace, since its usually the first cell to reach LVC. Draw your own conclusions


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## dimitri (May 16, 2008)

Also, instructions for any rechargeable battery of any chemistry or type usually state that you must perform a "full charge" before using it. Now, "full charge" does not mean "max safe voltage", does it?

Its simply a logical statement to prevent some idiot to attempt to use the battery out of the box, not get expected results and sue the manufacturer. Its in the same ballpark with "this coffee is hot" label in McDonalds 

"full charge" can mean different things to different people. Some consider battery at "full charge" when its at "max safe voltage", but others like me consider it when battery has enough energy stored for my needs, and my personal experience puts "full charge" at 3.8V per cell.

I don't mean to sound like an ass, but LiFePo4 has way too much mystery and confusion around it, which goes away very quickly once you start using them every day. 

JRP3, don't feel bad , I was just as paranoid as you are after plunging so much money into it 

Who knows how long they will last, right? Maybe there is some "magic" in charging to 4.25V to make them last longer? But I personally think its baloney or perhaps a conspiracy to make people destroy their cells so they will buy more after 1 year warranty expires, how's that for a theory?


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## JRP3 (Mar 7, 2008)

Ok I posted a link to the wrong thread 
Try this one:
http://www.nabble.com/TS-LiFePO4-initial-charge-to22981597.html


> when you get the TS batteries, it will come with an instruction sheet that says it needs to be 4.2 volts, to seat chemistry.
> I used a power supply at about 20 amps for the 90 aha





> m gol is correct, when you first charge the batteries they are suposed to be charged to 4.2v to activate all the material in the cells according to TS
> 
> Dave Kois
> Powered By DC, LLC
> www.poweredbydc.com


Now I realize the voltage doesn't matter as far as balancing is concerned, but if TS is recommending the initial 4.2 volt per cell charge I doubt they are doing it to have their cells die prematurely. They had enough problems with that in the past and there are too many competitors out there now fighting for our lithium dollars.


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## dimitri (May 16, 2008)

I just read that whole thread, then pulled my TS book and the green sheet and read every word.

IMHO, people take Chinese translation too literally. My conclusion is the same as I stated before, there is no such thing as "activation charge". Volatge of 4.25V that is stated in the docs is simply "max safe voltage" , not meant as "full charge" voltage.

There is no indication anywhere in the docs that first charge is of any significance or importance, all it says is that battery comes half charged and needs to be fully charged before use, doh!

I'd love to see some independant technical analysis and explanation of "material activation" in LFP cells, until then I think its bunch of BS.

Think about it, if it was such important procedure, would they leave it to the customer? Hell no, that would be a huge liability for them. If such procedure was required, they would state it in huge red letters all over the doc.


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## dimitri (May 16, 2008)

Why not make it fun and let everyone chime in with their interpretation of TS documentation. I just scanned this from my doc. This is the part that people mention in that other thread JRP3 linked above. 

I even left original Chinese, maybe someone fluent can give us their interpretation.

My personal interpretation is that 4.2V is mentioned simply as indication of max charge, a voltage level that is not to be exceeded, not that "you must charge to 4.2V to activate it".

Your thoughts?


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## tomofreno (Mar 3, 2009)

JP3,

I asked the same question about 3.6V versus 4.2V for SE versus TS on the Yahoo Thundersky user group. No responses yet. There was a good discussion on charging cells there a couple weeks ago with folks with a year or so experience chiming in.

Charging a LiFePO4 cell involves incalcating or inserting lithium ions into the graphite anode. I don't see where there would be any kind of "activation" involved in this process. The swelling is because lithium ions are a bit larger than the space between carbon atoms in graphite so there is strain and swelling introduced during charging, especially if overcharged. 

It doesn't seem worth the risk of overcharging and damage to set your bms or shunt regulators to bypass at 4.2V. Lots of folks say the voltage really increases fast once you reach 4.2 to 4.25V. Maybe because you've "stuffed" about as many lithium ions as you can into the anode, so resistance starts climbing fast. I've never read of a problem with undercharging other than a bit less range, and there seems to be very little difference in stored energy charging to the higher voltage. That said, Dave Kois has quite a bit of experience with these cells and I have zero.

I bought SE cells. I plan to set the shunts at 3.6V, maybe 3.55V. I don't understand why SE says the charging voltage is 3.6V, but I'm sure not going to exceed what it says right on their spec sheet. Maybe they just want to lower risk of customers overcharging and destroying cells and coming back to SE for warranty claims. I figure all I loose is a few miles range, better than a cell or more.

Tom


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## JRP3 (Mar 7, 2008)

dimitri said:


> My personal interpretation is that 4.2V is mentioned simply as indication of max charge, a voltage level that is not to be exceeded, not that "you must charge to 4.2V to activate it".
> 
> Your thoughts?


If that's the only mention of the 4.2 voltage I'd be inclined to agree with you.


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## JRP3 (Mar 7, 2008)

tomofreno said:


> It doesn't seem worth the risk of overcharging and damage to set your bms or shunt regulators to bypass at 4.2V.


I would only charge single cells or cells in parallel if going that high, not count on a BMS.


> I bought SE cells. I plan to set the shunts at 3.6V, maybe 3.55V. I don't understand why SE says the charging voltage is 3.6V, but I'm sure not going to exceed what it says right on their spec sheet. Maybe they just want to lower risk of customers overcharging and destroying cells and coming back to SE for warranty claims. I figure all I loose is a few miles range, better than a cell or more.
> 
> Tom


This was my initial thought on the lower rating for the SE cells, and somewhat contradicts the need to charge the TS cells to 4.2 since I doubt the chemistry is that radically different.


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## JRP3 (Mar 7, 2008)

Some more info supporting the interpretation that charging to 4.2 is not necessary:


> http://www.diyelectriccar.com/forum...onggest-high-capacity-p130324.html#post130324
> Hello JRP3,
> SE material is different with TS/TK. So the working voltage range is also different.
> 
> ...


So if the cells have already been charged an discharged I see no reason for a "4.2 volt activation charge" for the TS/TK cells.


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## Grant_NZ (May 28, 2008)

Interseting...

Whats so different about the chemistry make up of SE cells compared to TS? Does 0.5v either way make the battery any better or worse? Seems a bit of a "here nor there" situation


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## JRP3 (Mar 7, 2008)

The newer chemistry, basically a finer compound I think, is more energy dense, which is why we are seeing 100ah cells in the old 90ah sizes, and 180ah cells in the same size as the older 160ah cells, and allows higher C rates.


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## dimitri (May 16, 2008)

JRP3 said:


> The newer chemistry, basically a finer compound I think, is more energy dense, which is why we are seeing 100ah cells in the old 90ah sizes, and 180ah cells in the same size as the older 160ah cells, and allows higher C rates.


I can see how a finer compound makes better density and C rates, but its still the same LiFePo4 chemistry, right? Chemistry of the battery determines cell voltage, so finer compound does not explain different voltage levels.

IMHO, the change in posted voltage levels is just a result of real life usage reports, longer tests, etc. Manufacturers may have realized that charging over 3.8V increases risks of overcharge, so they changed their docs to minimize warranty claims on overcharged cells.

Of course my experience so far only been with TS, so its just a theory, but even with TS cells there is about a minute of charging between 3.8V and 4.2V, so for any practical purpose they might as well state 3.8V as a max charge voltage.


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## JRP3 (Mar 7, 2008)

Though I do agree the new voltage range may just be a more accurate representation of the true working range, to be accurate I don't think it's only the particle size that is different. They are using the new Aleees formula:
http://www.aleees.com/en/product/LFP-NCO.htm


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## bblocher (Jul 30, 2008)

I agree with Dimitri after spending time with my cells as well. There is too much mystery being added to these cells, and perhaps by those who are stuck in the LA era not wanting to move to the new technology. 

They are really quite simple, and a simple BMS is all that is needed. However I disagree on cell level monitoring not being needed. I feel this is a must. It doesn't matter how well balanced your pack is, some of the cells will still reach shunt voltage sooner than others. To keep the cells safe you two options at this point. Stop charging, or get rid of the energy in the cell that is full (there are multiple ways to do this).

From my experience, anywhere between 3.6v and 3.8v is a good /shunt voltage. I wouldn't go any lower, however. These cells hold voltages really well until the last bit of the charge cycle. If your charger starts cutting back amps too soon, it will take an exteneded period of time to reach full charge. Some chargers only allow set amounts of time at different charging states as well, leaving you with a paritally charged battery. My rule of thumb after some time learning the cells is to go with 3.8v if you have the ability to back off the charger. If you're going the risky path with no charger communication, keep it low (3.6v or lower), but I strongly recommend a charger integrated solution where your high voltage is monitored.


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## Grant_NZ (May 28, 2008)

bblocher said:


> I strongly recommend a charger integrated solution where your high voltage is monitored.


Hi bblocher, what chargers would you recommend that would do this? Thanks


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## bblocher (Jul 30, 2008)

Any charger that accepts some form of input for cuting back should be able to be used. The most common method is using the temperature probe input. There are quite a few out there (Zivan, Manzanita Micro are two well known brands). Basically these chargers commonly have a temp input for LA batteries to compensate for climate changes. For LiFePO4 you wouldn't use this option as is, so we can take advantage of that and use it to cut back the charger in the case of high voltage instead.

The charger is looking for a resistance measured across the input terminal for the probe. Each charger will be different, some testing is required to find the resistance range the charger will accept. Once you find a resistance that pulls the charger down to a level you want in a high voltage scenario you can work that into a simple circuit that places the resistor across the charger input.

This is how Dimitri has been doing it for awhile now. I'm getting ready to remove my TS BMS from it's high voltage monitoring duties (extremely buggy) and replace it with this solution.


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## dimitri (May 16, 2008)

To be honest, there is one little caviat in Zivan's integration of temp probe input. When triggered, it does not pull back, it just stops rising and levels on whatever voltage/current that was present at the time. So, if for some reason ( very significant pack imbalance ) one cell trips the HVC while charger is still in high current phase, it will remain in high current and quickly overrun the shunting ability and overcharge the cell.

This situation is virtually impossible if your pack is reasonably balanced since charger will be in low current phase by the time first cell gets to HVC. 

This is why initial balancing is absolutely critical and if done in series then you have to sit next to the pack and watch those LEDs like a hawk  to make sure first one comes up after charger has slowed down.

Once initial balance is done, then BMS will keep the pack balanced and you can sleep in peace while your pack is charging 

Ideal charger with BMS input should immediatly drop to low current when first cell trips HVC.


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## bblocher (Jul 30, 2008)

Thanks Dimitri, that's good info. Looks like I need to get to work then on an inline charger regulator solution then so we can protect the cells using any charger and not have to worry about how they implement the thermal probe logic.


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## JRP3 (Mar 7, 2008)

Brian, have you considered running wires from the cells to a remote board and larger heatsink? I ask because in my setup, and probably others, some of my cells will be buried so I couldn't see the leds and some may not have enough room on top to fit the heatsink or have good airflow around it.


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## bblocher (Jul 30, 2008)

JRP3 said:


> Brian, have you considered running wires from the cells to a remote board and larger heatsink? I ask because in my setup, and probably others, some of my cells will be buried so I couldn't see the leds and some may not have enough room on top to fit the heatsink or have good airflow around it.


The larger heatsink really isn't required, these are rated for how much the module is limited to from the power resistor. The boards can be mounted remotely or on the cell.


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## JRP3 (Mar 7, 2008)

bblocher said:


> The larger heatsink really isn't required, these are rated for how much the module is limited to from the power resistor. The boards can be mounted remotely or on the cell.


I was thinking more along the lines of all the modules mounted on a single larger heatsink but I guess there is no real benefit to that.


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## tomofreno (Mar 3, 2009)

It is my understanding that evcomponents has a circuit similar to what you describe Brian. I was told it decreases the current output of a Manzanita charger when a cell high voltage signal is received (they made it for use with the Elithion bms). I am trying to order the lithium voltblochers, a Manzanita, and this circuit from them. I also plan to glue a thermal cutoff fuse to each board, and daisy chain them together with a relay to shut off the charger if a board exceeds 200 F as an extra safety precaution. Maybe I should wait and order Voltblochers after you finish this next revision 

Tom


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## JRP3 (Mar 7, 2008)

I thought the Elithion BMS also balanced cells as well as controlled the charger.
http://www.evcomponents.com/ProductDetails.asp?ProductCode=BMS


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## tomofreno (Mar 3, 2009)

It does. I didn't say it did not. It only shunts 0.1A though. The maker assumes you are starting with a well-balanced pack, and it does not become significantly unbalanced during charging/discharging.


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## dimitri (May 16, 2008)

tomofreno said:


> It is my understanding that evcomponents has a circuit similar to what you describe Brian. I was told it decreases the current output of a Manzanita charger when a cell high voltage signal is received (they made it for use with the Elithion bms). I am trying to order the lithium voltblochers, a Manzanita, and this circuit from them. I also plan to glue a thermal cutoff fuse to each board, and daisy chain them together with a relay to shut off the charger if a board exceeds 200 F as an extra safety precaution. Maybe I should wait and order Voltblochers after you finish this next revision
> 
> Tom


My understanding is that Manzanita was updated to recieve the BMS signal and slow down, the BMS board itself doesn't do anything other than pass the signal, which is the same that any other BMS can do just as well. My BMS does it and Brian's upcoming version would do it. You just need to know the signal specs ( NO/NC, high/low, etc. ). There is nothing special about the way Elithion BMS works, its a nice system according to its documentation, like you said it has too low shunting current IMHO, and yet to be proven quality/support wise, but overall a good addition to the market. You couldn't buy it yourself due to seller's support cost, so we can thank Dave Kois for making it "semi affordable" for us DIY crowd.


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## dimitri (May 16, 2008)

bblocher said:


> Thanks Dimitri, that's good info. Looks like I need to get to work then on an inline charger regulator solution then so we can protect the cells using any charger and not have to worry about how they implement the thermal probe logic.


Brian, have you considered that inline regulator might mess up "smart" chargers by introducing voltage drop and current limiting into the circuit? I suspect that Zivan and Manzanita type chargers will sense abnormal behavior and could go into the error mode shutoff. I think inline regulator was meant for "dumb" chargers.

Also, considering cost and complexity of a good 20A-30A inline regulator you might as well make the whole charger, its not too far off. See the DIY Charger thread here and a link to another forum, most of the DIY charger complexity lies in same functions that you describe as "inline regulator".

I don't see a point of designing $150-$250 device that requires separate charger purchase, when you can expand it into the whole "smart" charger for another $100-$150.

Am I off target here?

Given Zivan temp probe limitation I described, its still an excellent choice for LiFePo4 combined with simple BMS.


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## bblocher (Jul 30, 2008)

Figures, six responses later I haven't received an email saying there were any updates. 

I'm definately not an expert on chargers. For any charger, here is what I'm thinking might happen as the current is limited.

Constant Current Stage:
Here the charger modifies voltage to maintain a set # of amps going into the batteries until the voltage reaches the desired level. Technically you shouldn't see any modules shunting at this point unless your pack is far out of balance. Either way, once the resistance is added this will drive the voltage up moving the charger to the next phase anyway.

Constant Voltage Stage:
Here the charger maintains the desired voltage and as the cells equalize to this voltage the amperage will continue to drop. The charger will look for the amperage falling below a certain value, or on some chargers, a certain amount of time maximum is also checked against. If the current limiting device maintained at least 2 amps, the modules could still shunt enough energy to keep up and the charger shouldn't consider this a complete charge.

This is my theory on how any charger would behave, regarldess of it having external inputs. 

Thoughts? I haven't lot more R&D to go, but it sure would be nice to open up the options on which chargers we can use when going the LiFePO4 route. 

I didn't consider making the full charger, but will keep that in mind. I was hoping to make more of a black box that had a pretty wide range of volt and amp allowances. Hook it up and go, leaving the configuration and prettyness on the charger side. I'm not sure what I'll do yet.

I just realized how off topic this has gotten, sorry all.


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## Lordwacky (Jan 28, 2009)

I have been emailing with Dave Kois about the Manzanita and Elithion BMS. As far as I can tell the manzanita doesn't interface that well with the Elithion. Just HVC is available. This is mostly due to the Manzanita and Elithion using different communication busses. However he is developing an add on package that will interface with the controller and the BMS making the mazanita a full blown smart charger. This add on package will also include a 7inch LCD touch screen for real time system monitoring etc. I do not know what the status of this system is but it sounded like it isn't that far out.

I'm a member of the 1st SE bulk buy and I've decided to also go with the Elithion BMS for 2 reasons, its fully featured and the addon package will be available giving me the functionality I want in a BMS. 

I ordered 48 180 ahr cells and the BMS price for that setup is $2100, which adds 43.75 per cell, which is admittedly quite steep. The add on package has been quoted to me to cost an additional $850 adding another $17.80 per cell. so my total cost for the BMS system will be $61.55/cell. I have to admit this is much more then I wanted to spend, but this is the system that Dave uses in his builds and has had good luck with it and frankly there just aren't other feasible options out there right now. 

Hopefully cheaper solutions will be coming out soon that have the same functionality.


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## tomofreno (Mar 3, 2009)

> My understanding is that Manzanita was updated to recieve the BMS signal and slow down, the BMS board itself doesn't do anything other than pass the signal


My understanding from Dave is that they made a separate circuit to perform this function. It is included with their new display Lordwacky referred to, and can be purchased to use with the Elithion and the display Davide offers for it. Dave thought they could also make it work with Brian's voltblochers. I agree the Elithion seems to be a good bms, but it is more than I budgeted for a bms, and it seems that the voltblochers/current decrease circuit/Manzanita should work well. I can combine this with a TBS gauge to read V,I,SOC for considerably less than an Elithion would cost. Btw Dimitri, do you sell your bms? If so where can I find info on it?

Tom


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## dimitri (May 16, 2008)

> Btw Dimitri, do you sell your bms? If so where can I find info on it?


In Classifieds section, here is the link 



> Hopefully cheaper solutions will be coming out soon that have the same functionality.


Cheaper solutions have been available for a while now. Also, charger cost should be included in cost comparison.

So, if we add $2000 Manzanita cost to your example it will become $100 per cell for Charger/BMS combo.

Lets compare with my BMS offer :
- Zivan NG3 - $1000
- Paktrakr with 6 remotes - $600
- 48 BMS modules - $960 ( before forum member discount )
- head unit to integrate HLVC with charger and controller - $80

Total $2640 / 48 cells = $55 per cell.

There you go, almost half the cost of Elithion / Manzanita combo.

Obviously PakTrakr does not have fancy LCD screen, but its a proven system and works great ( although has a limit of 40-48 cells ), but we don't even know what the future LCD module from Elithion will do and how well it will work, so its hard to compare.

To go even lower cost, just get simple VoltBlochers and Zivan or Elcon PFC or any other decent charger and you will have enough protection as long as you set your high / low limits within safe margins, which will of course result in a bit lower range, but its a tradeoff.


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## Lordwacky (Jan 28, 2009)

dimitri said:


> In Classifieds section, here is the link
> 
> 
> 
> ...



I wasn't trying to be insulting or dismissive of your product/future product. I did say that in my post that the elithion system had the functionality that "I" wanted. I didn't really elaborate on what "I" wanted. I'm sure your paktrakr/BMS/Zivan is a good system but from everything that I've read it didn't really have the functionality I was looking for. While I completely a agree that as far as a pure BMS system goes, yours seems to be perfectly acceptable. I read your classified add when you posted it and I was very tempted to go with your setup and may have if you were willing to support the Manzanita charger.

I was just trying to post some concrete figures on the forum so readers can get an idea of what one of the options actually costs. 

These are the reasons I choose the system I did. I recognize that these are all nice to haves and I realize I paid a high premium for them, probably too high.

1) Manzanita is more powerful more universal charger then the Zivan chargers, my charge time at 156V will at least a x3 faster then with the NG3 (I ordered a PFC 30) but as you point out more expensive

2) Manzanita can charge at either 110V or 220V with virtually no effort to switch back and forth. Admittedly I did like the NG5 which does both 3 phase 208 and single phase 220, but opportunity charging (110V) would be a problem. I have 3 phase at my build location (parents house) so it would have been nice to use it.

3) I would not have bought the Elithion system if evcompnents wasn't coming out with the add on, the add on package is what sold me. Elithion is not developing this system, evcomponents is developing it, and it sounds like it is a full blown "carputer" that will allow me to expand its capabilities. it will allow me to data log, possibly add things like a VSS,TACH,GPS all into the one system. These were all things that I wanted to add and it turns out that EV components is getting me halfway there already. I'm not saying it has all that off the self, but since it is a full blown carputer system with windows xp OS it has more flexibility then the paktrakr interface.

Now all that having been said. Dave did say that they were planning on stocking the new Volt Blochers with LVC and HVC when they came available. He did not say when that would be and he did not mention to me that they would try to integrate those with their carputer system as well. If I had known that I may have decided to wait, but I didn't know that at the time.

So I'm sorry if I offended you by saying no other feasible options are out there, that is not true.


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## dimitri (May 16, 2008)

Dude, where did you get the idea that I took any offense?  Absolutely not! In fact it was nice that you broke down component costs by cell, etc. I just wanted to "correct" the statement that cheaper systems aren't available, but you are right that "same features" cheaper systems are not available, so it all comes down to what features people are ready to pay for. 

I am not pushing my BMS by any means, at the time I offered it there weren't many alternatives, but today there are and in the future may be even more, its all good.

I never used Manzanita myself that it why I wasn't comfortable selling my BMS to be used with it. I am sure anyone with some skills can easily hook up my modules to Manzanita charger, its not a rocket science.

I do feel, however, that Manzanita products are grossly overpriced and my crystal ball tells me they will have lots of competition very soon  , that is just my opinion, no offense to Manzanita or their customers.

I can't wait for EV Components to publish specs of their upcoming Carputer, I think that would be an awesome addition to DIY EV market.


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## dimitri (May 16, 2008)

bblocher said:


> Thoughts? I haven't lot more R&D to go, but it sure would be nice to open up the options on which chargers we can use when going the LiFePO4 route.


Brian,

during constant voltage stage inline regulaltor will introduce some voltage drop, so when charger senses max voltage it will not be correct battery voltage. Charger will stop too soon, I think.

Also, do you plan to control IGBT with PWM or analog signal? Analog might cause too much heat loss, and PWM might throw off charger's voltage sensors.

I might be totally wrong though, perhaps some testing is in order


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## Elithion (Oct 6, 2009)

Lordwacky said:


> As far as I can tell the manzanita doesn't interface that well with the Elithion.


Actually, it does OK. It takes an opto-isolator (or relay) between the Lithiumate BMS output and the Manzanita charger RegBus input. You also have to turn off a few DIP switches on the charger to allow it to turn back on.

Schematics and details are here:
http://liionbms.com/php/bms_manzanita_micro.php
which should be of help to anyone interfacing to the PFC charger, regardless of the BMS used.

D'de
________
Green Crack


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## Elithion (Oct 6, 2009)

tomofreno said:


> [The Elithion BMS] only shunts 0.1A though. The maker assumes you are starting with a well-balanced pack, and it does not become significantly unbalanced during charging/discharging.


If I may:
*) It's actually 0.2 A
*) Chances are that you'd be fine with 0.2 A http://liionbms.com/php/wp_balance_current.php "How much balancing current do you need? "
*) You can always add Balance Boosters, which bring that up to 2 A

D'de
________
Ultimate fighters


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