8s Lifepo4 BMS on Li-ion Cells?

[grosen84]

I received 4 of these batteries for free and I'm hoping to use them as the start to a solar generator. They're 8s li-ion batteries, epoxied into these enclosures. I can't break them down without destroying the plastic, since they're siliconed together. Is there a difference, other than cut off voltages, between lifepo4 bms and li-ion bms? Could I use a lifepo4 bms on these batteries until they're eventually replaced with lifepo4 cells? I know I'll be losing out on capacity with lower operating voltages but I'd like to build a 48v system and not have to rebuy components later. Also, I did some searching but was unable to find any info on these. If someone is familiar with them please let me know. The person who had them previously wired up one of the connectors to the balance leads, so I can wire a BMS in, also curious about the 13 or so other wires coming off the board...

 

[MisterSandals]

I know I'll be losing out on capacity with lower operating voltages

This becomes dangerous on the low voltage end.
What BMS? Smart?

 

[MurphyGuy]

Sure, that will work. No problem on the high side as a LiFePo4 BMS won't allow the lithium ion cells to charge past 3.6 volts or so.. But on the lower side, the lithium ion cells will be damaged by the time the LiFePo4 BMS cuts off because the LiFePo4 chemistry has a much lower bottom end.

 

[grosen84]

This becomes dangerous on the low voltage end.
What BMS? Smart?

Haven't decided on which all-in-one I'll use, but could I theoretically set it to protect the low voltage aspect? Probably get a few daly bms's. On the flip side, is there an all-in-one that would accept near the full voltage from these batteries? I'd run 2s2p as independent units.

 

[MisterSandals]

Probably get a few daly bms's

If you do not own the BMS yet, why not just get a smart BMS or a dumb one specifically made for your battery chemistry "(lithium ion" is not necessarily specific).

 

[grosen84]

If you do not own the BMS yet, why not just get a smart BMS or a dumb one specifically made for your battery chemistry "(lithium ion" is not necessarily specific).

The other issue is the total voltage. My goal is to get a 48v inverter, but their input seems to be limited to less than the full voltage on a 3.7 based 16s battery. 3rd issue is I can't find these batteries, at all. I tried googling international rectifier, infineon, the model number, everything I could find on it. I almost wonder if they were used to run equipment for the rectifier company, not actually retailed. So unless I destroy one looking for a label on the pouch, I don't know the specific chemistry.

 

[Nick0016]

Use an smart BMS like JKBMS which you can configure for LifePo4/Li-Ion/LTO and if needed customize the upper/lower voltages...