Adventure in LiFePO4

[timholmesjr]

I currently have a 48 kWh homebuilt battery from Gen 2 Nissan Leaf cells connected to an 8k Outback Radian and monitored by a Batrium BMS. The system has been running for about 3 years with no issues. I have been debating playing with LiFePO4. In particular the EVE 280 Ah cells. What is the voltage range that most people operate the EVE cells within to minimize degradation? Also asking what BMS I should use is a controversial topic, but if I am starting from scratch with the current hardware config is there an obvious candidate or two I should evaluate? It seems the JBD is popular on the forum. I am still combing through all the posts, so I apologize if this has been covered in detail. Thanks in advance for any help.

 

[sunshine_eggo]

LFP doesn't work like our NMC. They behave more like lead acid in terms of charging. You can't target SoC range by voltage.

Two main options:

Fast charge to 3.55-3.65V/cell, 30 minute absorption, 0.05C tail current.
Slow charge to 3.45V/cell, 2 hour absorption, .02C tail current.

Fast charge will get you rated cycle life.
Slow charge may improve cycle life and top out in the high 98% SoC range.

IMHO, if you have a reliable well designed NMC system, there should be a very compelling need to switch to LFP.