Grid Tied Si-6048 and 2 new LiFePO4 Relion RB48v300 in parallel to replace 8 Fullriver DC400-6 in series?

[Swen G]

Hello everyone!

One of our Fullriver DC400-6 just recently died and we are looking to replacing our battery bank. I have contacted a DC battery supplier and he had some Relion RB48v300 around, that a customer had ordered but then did not need. So i am thinking about going from AGM batteries to LiFePO4. I contacted SMA-US, but they only gsend me a PDF showing a few "approved" batteries, and not a single LiFePO4.
So i guess what i am asking is: Does anyone know whether i can run a SI-6048-US and a Sunny Boy with two RB48v300 to get more Ah?

 

[snoobler]

Welcome to the forum.

There's fundamentally no difference between a "dumb" AGM battery that can't communicate with an inverter and a LFP battery that can't talk to the inverter either. The only way they communicate is via their voltage.

16 cell LFP (RB48v300) and 48V AGM have almost perfectly overlapping operating voltage ranges.

Your AGM can run from 42V to 58.8V.

LFP can run from 40V to 58.4V.

As long as you can program the charger for an absorption of about 57.6V and a float no higher than 54.4V, then there is no reason you can't use those batteries.