Charging 12v 100amp LiTime Lifepo4

[markhodges78]

I have a 12v 100amp LiTime Lifepo4 and a Cellpro power lab 8v2 40 amp charger and I was wondering if anyone has any experience charging with this charger. I have charged many small lipo and lifepo 4 batterys with this charger but nothing with a built-in BMS just wanting to know how to set my charger up to charge this battery

Thanks in advance

 

[sunshine_eggo]

I have a 12v 100amp LiTime Lifepo4 and a Cellpro power lab 8v2 40 amp charger and I was wondering if anyone has any experience charging with this charger. I have charged many small lipo and lifepo 4 batterys with this charger but nothing with a built-in BMS just wanting to know how to set my charger up to charge this battery

Thanks in advance

Normally:
14.4V with 0.05C cut off (5A)
13.5V float if needed in a cyclic power system. If storing, no float needed.

Not knowing how this charger will react to having the BMS cut off charging due to over-voltage protection, I would charge to 13.8V @40A to normal termination. I presume it will cut off around 4A. Then charge at 13.8V @2A for the shorter of 1) as long as it will accept current or 2) 24 hours.

After that charge to 14.4V @ 40A. You may find it's already full.

The idea is to use the extended lower voltage charge time to allow the BMS to balance any significant cell issues.

 

[markhodges78]

Normally:
14.4V with 0.05C cut off (5A)
13.5V float if needed in a cyclic power system. If storing, no float needed.

Not knowing how this charger will react to having the BMS cut off charging due to over-voltage protection, I would charge to 13.8V @40A to normal termination. I presume it will cut off around 4A. Then charge at 13.8V @2A for the shorter of 1) as long as it will accept current or 2) 24 hours.

After that charge to 14.4V @ 40A. You may find it's already full.

The idea is to use the extended lower voltage charge time to allow the BMS to balance any significant cell issues.

Which C/? termination would I use my options are C/3, C/5, C/10, and C/20?

 

[sunshine_eggo]

Based on my interpretation, C/20 is the same as 0.05C.

 

[markhodges78]

Sorry wanted to give you a little more detail

 

[markhodges78]

if you want i can give you the link to the software and you can see all the settings that's available without the charger ?

 

[sunshine_eggo]

C/20 is correct.

 

[markhodges78]

C/20 is correct.

Thank you for all your help it's much appreciated..

 

[markhodges78]

Ok So I cant set the Termination to C/20 the charger with not let me for that preset it will only let me use C/10 and below but here are the results from the first discharge and charge..
I discharged the battery over a 12 hour period and the charger ended the discharge with 11.215 volts in the battery. Pulling out 90.1928amps pulling a max of 8.7 amp load. It started out pulling around 2 amps and worked up to 8.7. The BMS did not end the discharge the charger ended it.. The charging took 4hours and 48 minutes at a charge rate of 20amps putting in 95.6481amps at 14.174 volts the charge was ended by the BMS but I'm not sure why because 14.174 isn't over voltage protection is it ? any ideas out there ?

 

[sunshine_eggo]

Ok So I cant set the Termination to C/20 the charger with not let me for that preset it will only let me use C/10 and below but here are the results from the first discharge and charge..
I discharged the battery over a 12 hour period and the charger ended the discharge with 11.215 volts in the battery. Pulling out 90.1928amps pulling a max of 8.7 amp load. It started out pulling around 2 amps and worked up to 8.7. The BMS did not end the discharge the charger ended it.. The charging took 4hours and 48 minutes at a charge rate of 20amps putting in 95.6481amps at 14.174 volts the charge was ended by the BMS but I'm not sure why because 14.174 isn't over voltage protection is it ? any ideas out there ?

From first post:

Not knowing how this charger will react to having the BMS cut off charging due to over-voltage protection (we know it won't kill it now), I would charge to 13.8V @40A to normal termination. I presume it will cut off around 4A. Then charge at 13.8V @2A for the shorter of 1) as long as it will accept current or 2) 24 hours.

After that charge to 14.4V @ 40A. You may find it's already full.

The idea is to use the extended lower voltage charge time to allow the BMS to balance any significant cell issues.

BMS protect cells. It cut off because one cell is likely hitting high limit and triggering protection. Battery is out of balance. My recommendations above were to avoid what you experienced and give the BMS more time to balance before the first hard charge as I described.

 

[markhodges78]

I would charge to (13.8V) @40A to normal termination. I presume it will cut off around 4A. Then charge at 13.8V @2A for the shorter of 1) as long as it will accept current or 2) 24 hours.

Oh wow I completely misread the (13.8V) @40A to normal termination.

BMS protect cells. It cut off because one cell is likely hitting high limit and triggering protection. Battery is out of balance. My recommendations above were to avoid what you experienced and give the BMS more time to balance before the first hard charge as I described.

Do you recommend a full discharge and a slow recharge and how can I avoid this in the future if charging at 20 amps. Sometimes when I get back from a fishing trip I only have about 8 hour before I have to head back out

Thanks Mark

 

[sunshine_eggo]

Holding the battery at elevated voltage will allow the BMS to balance continuously.

Does your charger have a power supply mode where you can specify constant voltage and max current? Many RC chargers have this feature to test electric motors.

The full discharge for discharge's sake will waste time. The bulk of balancing occurs at and above 13.6V, which will only be at the tail end of charging. If you want to burn off only ~5-10Ah and then charge slowly, that might help.

Once the batteries are balance, regular charges to full should serve to maintain balance.

 

[markhodges78]

Holding the battery at elevated voltage will allow the BMS to balance continuously.

Does your charger have a power supply mode where you can specify constant voltage and max current? Many RC chargers have this feature to test electric motors.

The full discharge for discharge's sake will waste time. The bulk of balancing occurs at and above 13.6V, which will only be at the tail end of charging. If you want to burn off only ~5-10Ah and then charge slowly, that might help.

Once the batteries are balance, regular charges to full should serve to maintain balance.

It does have a Constant current setting

 

[sunshine_eggo]

I would be concerned it would let the voltage increase and trigger BMS protection. Constant voltage is needed.

 

[markhodges78]

I do have this which has a built-in power supply 0-15 volts what are you thoughts on using this ?

 

[mikelamay]

OP, was this ever figured out? I have a LiTime 100 mini and its doing same thing. Im going to get a CV/CC power supply and charge based on Sunshines advice.


Surprised I dont hear more on this issue with BMS cutting creating a quick voltage spike ~16volts.