LiFePo4 in standby service

[Glock24]

I'm considering using small LiFePo4 batteries to replace VRLA batteries in a UPS. I've searched about this but I can only find info about max charging or float voltages, but nothing about proper voltage for long standby use.

From what I know lithium batteries don't like sitting at 100% or too low charge for long periods of time.

In an UPS the battery would not be cycled regularly, instead it would sit at whathrver voltage you set as charged for long periods of time, many months probably.

What voltage would be suitable in thus scenario so ghd battery does not get damaged?

 

[fatjay]

The voltage curve for LFP batteries is extremely flat, you really can't trust it to give accurate readings. The best indication is what the BMS says. And yes, you need a BMS, otherwise there can be bad things that happen.

Personally, I would not use a LFP battery in a UPS application. That being said, I'm using one now, but it's a temporary situation and not for extended use.

LFP is best stored at 30-50% for extended periods, which is the opposite of useful for UPS applications.

 

[740GLE]

Floating at 3.35v or 3.40v “shouldn’t” kill the cells.