Solar battery buying guide

Thinking about adding battery storage like the Tesla Powerwall to your solar energy system? Our buying guide will help answer your questions to help you decide if it is worthwhile for your set-up.

Have a question about solar batteries? Leave your comment below.


7 posts were merged into an existing topic: State Solar Programs for PVs and Batteries

Looking for battery storage system for home with three phase power (and grid connected as form of back-up).

I’ve had a quote for a Fronius system - but it is quite small.

Tesla has upgraded the controller for its PoweWall 2 (the Backup Gateway 2) to enable up to 10 Powerwalls to be connected on-grid for a three phase home.

Question: are there any other contenders?


Much of this is probably elementary to you, but could be informative and helpful non-the-less as you get past the intro, noting products evolve quickly and this item is already 9 months old.


I’d suggest looking at Victron gear, you can do 3phase, and just set the mains to be “shore power” as used in boating, a market Victron is pretty huge in.

Meanwhile, in my now 6 year old off-grid DIY system with 21kWh of storage, another cell appears to have quite reduced capacity (rough estimate 50-60% of original 400AH, but not measured accurately).

Short term plan is to parallel the earlier retired weak cell with the newly weak one, to increase its capacity. Time will tell if that is a satisfactory solution, but it isn’t the sort of thing you could do with a Powerwall or other commercial battery that was showing reduced capacity.


Will Choice update the website when data from the Redflow Zcell become available?

As Redflow is an Australian company, using Australian developed battery technologies and an alternative to lithium (potential problems with extraction of Li-ion metals outlined in another thread), it may be one that many of us many be interested in should its performance meet advertised outputs.


I imagine there will be plenty more testing that will occur, I’ll be sure to flag your comments about the Redflow Zcell.


My 21kWh LiFePO4 CALB battery (DIY from 16 X 400AH cells) has been in operation for 6 1/2 years now and despite being worked very hard quite frequently, particularly in very hot summer weather (no temperature controlled environment here!), is still doing ok, although capacity is (as expected) down somewhat from new. Although I have replaced* one cell, with a Winston as CALB 400AH cells were no longer available, it was still much better value than any of the commercial offerings.

  • now in parallel with another weaker cell to bring its capacity up closer to the rest