Solar PV battery options

These are the battery control parameters within the Solis

Cheers appreciate that Graeme 👍

Cheers Graeme I notice your equalising voltage is lower at 57.5 and will change mine to that.

Sorry I'm little bit confused as to where you have max charge set to 57v? On the Solis settings or bms?

jeez just goes to show you dont know what is underneath the shiny casings of these off the shelf batteries

One cell failing means the the charging voltage is therefore split across 14 rather than the original 15 cells. If cells were around 3.45v and one failed, it would add 0.25v to each other cell, and if the BMS failed to trigger shutdown based on one cell and only shutdown based on total pack voltage, it could keep charging !!!

I understand that part. The BMS in these batteries is pretty good from what I've seen. Each cell is monitored and each cell has temperature probe also, so it should have noticed that one is a runner i think there is more to it.

Get the biggest battery you can afford. 2.4kWh is nothing. With 4.8kW system running at full blast it will only take half an hour to charge it fully. My daily consumption is close to yours. I do work from home for over 10 years, have 4.5kW system and 10kWh battery was not enought for me hence I upgraded to 20kWh.

I have east west, 6.6 and a 5 kw battery. I work from home and use about 20kw a day.

Even wfh I recommend a battery. Without a battery u will never get any work done, cause every time sun shines u will run around trying to turn stuff on...and when a cloud passes over you will run around turning it all off. Good luck.

I wanted to build a system that was ‘future proofed’ with the ability to add a battery down the line. However I just found out the company I got a very good quote from, only install single phase inverters. with the excess going to my hot water.

I know you could install a battery later into this system which would have a built in inverter. But there is an added cost. One I checked was €7K for a 5KW battery which had a built in inverter.

how much of a deal-breaker should I consider this? Anyone have a single phase inverter and wish they had gone with a hybrid inverter instead?

But all is not lost. You can add a separate Storage Inverter onto which you can add batteries. Look at the Sofar ME3000, onto which you can also attach a DIY 10kW battery bank for about €1500 (see other thread)

Thanks both.

You are right, I’m mixing up my terminology. What I meant was that my installer is going to provide a standard inverter, not a hybrid.

Which I suspect is why the price is reasonable ~€5.5K (after grant) for 4.9KW system plus eddi.

But it sounds like even if I go with a standard inverter that I could easily add a battery later anyway, albeit with an extra piece of kit like a Sofar ME3000. Is the €1500 you mention the total price for sofar + battery championc? Or just the battery?

€900 is the cheapest ive been able to find , from The Netherlands , nothing on adverts.