Recently, I upgraded my 32 x Lead Acid batteries for 3 x PylonTech 3.5 LiIon batteries, which was a straight replacement operation.

I was going to sell the Lead Acid batteries for whatever I can get for them (less than 2 years old), but then the thought occurred to me: why not use them?

I have 2 5kVA Axpert inverters, each with 12 x 270W solar panels, and my thinking is to put the new Pylon batteries feeding the one inverter, and the old Lead Acid batteries feeding the other inverter.

The only problem I can see is that with the Axpert inverters, I can’t set the battery types / switching voltages individually; they copy across automatically; so I’d need to be careful with the settings.

Anyone have some thoughts?

1 hour ago, Peter_DM said:

I have 2 5kVA Axpert inverters, each with 12 x 270W solar panels, and my thinking is to put the new Pylon batteries feeding the one inverter, and the old Lead Acid batteries feeding the other inverter.

If the inverters' outputs are paralleled, then there has to effectively be only one battery, so the actual batteries would have to be paralleled. But paralleling lead acid and LFP, especially 15S LFP, isn't going to work.

What you could do is split the loads, putting half on one inverter and half on the other, keeping the systems separate. That solves the problem of the separate settings.

But then it will be like a computer with two hard drives; you've forever running out of space on one when you have space on the other, and you wish you could just make one big hard drive. I think you'd hate having to manage the loads all the time.

Edited February 14, 20197 yr by Coulomb

11 minutes ago, Coulomb said:

But paralleling lead acid and LFP, especially 15S LFP, isn't going to work. 

Right. Cause at 54V a Pylontech battery is switching off already on overvoltage, while a lead-acid bank is hardly getting a good float 🙂

Thank you both for the replies.

I guess I'm not going that route.