# Life04 batteries max & min volts



## Elithion (Oct 6, 2009)

evnz said:


> i am unsure what to set as max volts and min volts when i set up the controller for life04 batteries


Is your BMS a Lithiumate BMS? If so, simply click the "LiFePO4" button in the Graphics User Interface. That's it!

Is your BMS a digital BMS, but not not a Lithiumate BMS? If so, talk to the company that makes your BMS, for some suggestions.

Is your BMS an analog BMS? In that case, you don't have a choice: the BMS is preset at the factory for some set of voltages, and you can't change it.


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## evnz (Jul 24, 2010)

Elithion said:


> Is your BMS a Lithiumate BMS? If so, simply click the "LiFePO4" button in the Graphics User Interface. That's it!
> 
> Is your BMS a digital BMS, but not not a Lithiumate BMS? If so, talk to the company that makes your BMS, for some suggestions.
> 
> Is your BMS an analog BMS? In that case, you don't have a choice: the BMS is preset at the factory for some set of voltages, and you can't change it.


I am trying to find out the volts not if or what bms i have please what is the volts the manufacture give 4 max and 2.8 min. 
If i go to low or to high i will kill them


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## ElectriCar (Jun 15, 2008)

I have Calb cells and charge to 3.4V which is a full charge. Discharge to around 3 minimum. Operating them in a tighter range as I understand it will lengthen their life. Not pushing them towards their limit also makes it less likely they'll be damaged if you're running sans BMS.


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## Elithion (Oct 6, 2009)

*Re: LiFeYPO4 cells (not Life04 batteries) max & min volts*



evnz said:


> the manufacture give 4 max and 2.8 min.


Then those aren't Life04 batteries, as you said; they are instead LiFeYPO4 cells (Thundersky type).



evnz said:


> If i go [too] low or [too] high i will kill them


Yes you will. And the only way to ensure you don't, is to use a BMS that:


knows the voltage of *each *individual cell, and
is able to *directly *stop your charger and your motor controller, to prevent over-charge and over-discharge (with no need for human intervention).
As an added bonus, a good BMS will allow you to use most of the energy in your pack, and to do so safely.

Here: pick one, buy it, have someone who knows what they're doing install it correctly, test it, and then breathe easy.

Concerning your original question: either the BMS is preset for Thundersky cells, or it comes with instructions on setting up the limits for Thundersky cells.

(Please understand that, without a BMS, anyone who tells you "use these limits for pack voltage", is responsible for the day that you *will *fry cells -- and _may _burn up your EV--, and then you'd be right to come back and blame them for it.)

Reference: Low voltage cut-off: a false sense of security, and CCCV chargers: a false sense of security .


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## ElectriCar (Jun 15, 2008)

*Re: LiFeYPO4 cells (not Life04 batteries) max & min volts*



Elithion said:


> Then those aren't Life04 batteries, as you said; they are instead LiFeYPO4 cells (Thundersky type).
> 
> 
> 
> ...


Sounds like you're saying if I buy your BMS and it shorts and frys a battery like BMS's have done many times that you'll warranty my battery and replace it? And I don't mean just one battery but any battery as long as I have your BMS because it won't allow them to go bad? That's BS and you know it!


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## DIYguy (Sep 18, 2008)

evnz said:


> Hi to all i am unsure what to set as max volts and min volts when i set up the controller for life04 batteries can you please give me your max and min and if you have bms or not
> Thanks
> Owen


Absolute Min Voltage *at no load*, should be set no lower than # of batteries x 2.5. I would bump this up a bit to likely 2.8, or even 3.0. Again, little energy below this point. If you have a Soliton and limp mode, you set a specific current level at a low voltage level to prevent heavy draw when limping home. Of course these are individual cell numbers and must be multiplied by number of cell.

If you can program min voltage under load you have to come up with a number you are comfortable with. Batteries will give out max energy at 1/2 of their nominal voltage. So, for LiFePo4, that is 1.6 volts. Again, I would move this up for battery protection I would say about 70% of your nominal. You could go a bit more if you are comfortable with the C rate specs from you particular brand.

Max charge voltage for a LiFePo4 cell is 4.2 volts. Above this level, damage results. NO ONE CHARGES TO THIS LEVEL! Again this is somewhat dependent on charger characteristics, and brand of battery. I think CALB's are recommended to about 3.6 and TS/Winston perhaps 3.8. reality is, very little energy is stored above about 3.5 for CALB and maybe 3.6 or so for TS/Winston.

Remember that these are battery settings, not motor settings. You will need to limit voltage to your motor if it is DC and your pack has a higher voltage than the motor can take. 

I'm sure some people could take issue with above numbers . . but these are general recommendations and will keep you safe.

If you give more detail, like brand and size of battery and also charger, it could be helpful to zero in on best settings.


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## DIYguy (Sep 18, 2008)

*Re: LiFeYPO4 cells (not Life04 batteries) max & min volts*



Elithion said:


> Yes you will. And the only way to ensure you don't, is to use a BMS that:
> 
> 
> knows the voltage of *each *individual cell, and
> is able to *directly *stop your charger and your motor controller, to prevent over-charge and over-discharge (with no need for human intervention).


Oh baloney. It may be one way, but it is not the only way. BTW, op asked for Controller settings. . . not weather he should buy a BMS. 

This guy represents a BMS company.

Bit of advise, if you use a BMS, DO NOT ALLOW IT TO SHUT DOWN YOUR CHARGER without an additional, redundant end of charge control. This is a potential problem to burn your car to toast.


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## rwaudio (May 22, 2008)

*Re: LiFeYPO4 cells (not Life04 batteries) max & min volts*



DIYguy said:


> Oh baloney. It may be one way, but it is not the only way. BTW, op asked for Controller settings. . . not weather he should buy a BMS.
> 
> This guy represents a BMS company.
> 
> Bit of advise, if you use a BMS, DO NOT ALLOW IT TO SHUT DOWN YOUR CHARGER without an additional, redundant end of charge control. This is a potential problem to burn your car to toast.


I agree, the terminology that people use is misleading! Some people will choose to go BMS free, others will choose a BMS, there is no right answer, but people should be given honest options.

It seems that there is no middle ground, people are either like Jack R who think BMS's burn down cars and as soon as you install one you are on a countdown to distruction. Others (like Elithion) use terminology that implies you MUST use a BMS or you will have the same outcome as Jack predicts just for different reasons.

On topic though, I have my Soliton1 set to 130v no load min voltage (2.82v per cell) and 110v full load min voltage (2.39v per cell) I'm running a 46S3P pack of A123 20Ah pouches.

The A123's are very stiff cells with minimal sag, so the pack is basically dead before I run into these limits.


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## GizmoEV (Nov 28, 2009)

*Re: LiFeYPO4 cells (not Life04 batteries) max & min volts*

Remember that your controller will be reading the battery voltage at its (the controller's) terminals not at the battery terminals so under load the controller will think the batteries are at a lower voltage than they really are.

I found that having my controller's low voltage set to 2.8Vpc that it would surge quite a bit under full throttle so I lowered the cutoff voltage and now it works just fine. I'm currently using 2.15vpc even though I also watch my Ah counter to make sure I'm not running my pack into the ground. If your controller has regen I would set the high end to 3.5-3.6vpc. Chances are unless you live at the top of a long hill you will never be able to regen more energy in than you took out just pulling out of your driveway and driving a mile or so. At least that is my experience.


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## Elithion (Oct 6, 2009)

*Re: LiFeYPO4 cells (not Life04 batteries) max & min volts*



ElectriCar said:


> if I buy your BMS and it shorts and [fries] a battery like BMS's have done many times ...


That is just a myth, and I wish you would act responsibly and stop perpetuating it.

Show me damage to a vehicle that has a BMS, and in all likelihood I'll be able to show you a vehicle damaged by a shoddy installation. The installer blamed the BMS instead of themselves (at best out of unawareness, at worse out of desire to hide their errors). I see that over and over, will all BMS brands; not just hobbyist, but "professionals" as well. Believe me, I have seen horrors.


People who install a BMS but don't hook it up so that it can shut down the charger and all the loads
People who hook the BMS to just some of the cell, or ignore the fact that the BMS hasn't been connected correctly and is only able to see only part of the pack
People who bypass the BMS just so they can get home
People who destroy a cell board and then use it anyway, pretending they didn't damage it
People who build dangerous packs, with B- connected to chassis, and in which a bus bar is so close to the chassis, that a short occurs at the first bump, and the arching can't be stopped
People who don't tighten the power connections, and, when they get loose, they arc and start fires
People who use badly built AC power cords, which catch on fire
People who do not install safety disconnects, and can't open the battery circuit in case of problems
So when the vehicle is damaged, what do you do? You look to see if there is a BMS in there, and, if so, case closed: "the BMS did it".


Honestly!


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## ElectriCar (Jun 15, 2008)

People on this site, more than one, have commented about boards failing to shut off and destroying cells. 

Regardless of who is at fault, I don't think they are a wise solution yet. I know you're financially tied to the success of your system thus your reply. I do think a BMS could be a good thing but I also know electronics fail from time to time. I know, I've repaired electronics for a couple of decades in an industry. 

Since there seems to be no way to fool proof them at this time, I don't think they're the way to go, for me anyway. 

Lastly, many here have discussed just spending the money one would use for a BMS and buy a few extra cells. There are other methods of monitoring that we've come up with that works without fail so far. I've only read about one individual here monitoring without a BMS having batteries fail for no reason. I bought one extra cell and it's still on the shelf, $250 worth.


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## Elithion (Oct 6, 2009)

Thank you, W.T.
I do appreciate the way you chose to word your latest post, in the spirit of cooperation, as we are fellow EV enthusiasts.


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## ElectriCar (Jun 15, 2008)

If it's determined that I need a true BMS, I know you guys make one of the best out there. I'm just gun shy a bit at this point.


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## evnz (Jul 24, 2010)

Thank you all for your coments 
My set up
Sol 1
Warp 11
45 x 100 ah winstons
In a bedford j1 (6mlongx1.7mwidex2m high


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