Can i use a 24V Lifepo4 charger for 24V Lion?

[edrift.eu]

I will repair several LIFEPO4 batteries with S8 LIFEPO4 block 3.3V. They are charged with a voltage of 29.33V = Thats 3,7V per LIFEPO4 cell.

A 7SP Lion/LiPO (samsung och Panasonic cells) will need a max charge voltage of 29,4V. That is almost EXACTLY THE SAME!

What i know from charging is mostly from this source:
http://www.powerstream.com/LLLF.htm

Will if work to safely to charge 7SP Lion on a 29.33V (1.8A) That is 0,01V LESS that a normal Lion charger would charge at per cell.

The only "problem" i can think of is that neither the charger or the BMS might not turn of at all since the battery would never be 100% full.

Keeping a battery connected to a charger, probably at a slow constant current of 0,1-0,2A will it harm the battery in any way?

 

[flippy]

Yes you can, voltage is the same so no problem.


And disconnect after charging. Do not leave floating for days on the charger.

 

[dogman dan]

agreed, no problem. FWIW, lifepo4 can take overcharge better than nmc or lipo, or other types of li ion. I've seen lifepo4 set up to charge to 4v, though 3.8v seems to be the max for most.

 

[redilast]

agreed, no problem. FWIW, lifepo4 can take overcharge better than nmc or lipo, or other types of li ion. I've seen lifepo4 set up to charge to 4v, though 3.8v seems to be the max for most.

Yes I have not researched the chemical reason for this, but LiFePo4 can "bleed" off excess voltage. I've charged them to even 4.20v and they just settled down to around 3.4v after a few hours (I don't recommend doing this regularly though). Normal 4.20v charge voltage Li-ions can become dangerous and unstable with such a high 0.5v overcharge.

 

[eva-michael]

Can use 8S LiFePO4 29.2V charger to charge 7S Li-ion. Charge curve of LiFePO4 and Li-ion are similar which is quite different from SLA battery.

 

[eva-michael]

agreed, no problem. FWIW, lifepo4 can take overcharge better than nmc or lipo, or other types of li ion. I've seen lifepo4 set up to charge to 4v, though 3.8v seems to be the max for most.

Some years before, many bms builder will set single cell over charge protection voltage to 3.8-3.9V. LiFePO4 can handle this voltage without problem and this will make LiFePO4 cells have more time to balance all cells during charge step. But many users don't know and worry about it 3.9V single cell charge protection. Then they set it to 3.75V, just to make users fell more comfortable.
Also Winston battery also confirm their LiFeYPO4(LiFePO4) cell can use constant charge 3.65-4V.

 

[dogman dan]

Agreed. charging lifepo4 to 4v is not a great idea. Most stop at 3.8v or lower.

But a slight overcharge for lifepo4 is no problem. 3.5 v is full, if it holds an overcharge to 3.8v overnight, great, it means your cells are in superb shape. Soon as you ride 10 feet, the voltage will always drop to 3.5v or less. Any more is just surface charge.

Don't overcharge lithium cobalt or lithium manganese like that!