Using Lithium LiFePO4 battery in a "ELK M1 Gold" system?

[mkg]

Did anyone consider replacing the lead acid battery (ELK 1280) in "ELM M1 Gold" system with a lithium (LiFEPO4) battery?
If yes, which battery will you recommend as a suitable replacement?

Thanks!
--Mike

 

[dwalt]

I would be careful. The charging circuit in the Elk M1 is designed for a lead acid battery. Charging a Lithium battery is very different.

 

[pparisi]

To be clear.. LifePO4 is not the same as lithium and the difference is critical.

Most LifePO4 batteries come with a BMS installed so they can be charged with a normal SLA charging circuit and swapped in to replace SLAs, which isn't true of all lithium batteries, an ordinary lithium battery requires a charger.

I've done upgrades to LifePO4 from SLAs (exact same batteries as the M1 uses actually) for UPS systems, and other similar systems no issues. (lawn mowers, toys etc)

I can't see there being an issue doing this with an M1 as long as you get a one with a good quality BMS and don't oversize it. honestly don't know why this isn't "standard" now with all M1s being sold the extra lifespan is great to avoid customer complaints about failing SLAs.

Next time I have to deal with a failed M1 battery I'll be replacing it with a LifePO4.