Additional Batteries

Hello,
I had a Givenergy system installed in November 2022. Inverter with 2 x 2.6kwh batteries. I have since got an EV and take advantage of the new tariff and would like to add to / double my capacity.

I've been advised by my original supplier that the batteries are no longer available as they're Gen1 and I'd need to start again. I don't want to do that for the obvious reasons. Can you mix generation batteries?

Can anyone advise me the best why to add batteries as I sense I'm not getting the full picture.

Thanks

Your supplier is both correct and incorrect at the same time. The new Gen 4 kit is high voltage and not compatible, but I believe that Gen 2 and Gen 3 equipment is compatible.
Certainly we now have a Gen 3 battery with a Gen 1 inverter.
I have been told the batteries can also co-exist together but we only have one battery at present so I cannot confirm that from personal experience. I would imagine someone here could though.
There are cabling differences any installer would need to handle but I think there are cables available which would handle the different connectors.

Gen 3 5.1 and gen 3 9.5 batteries are available and compatible

RussHead as the others have said you can buy Gen 2 and 3 batteries (5.12 and 9.5kW) and they are compatible with your inverter. You can have up to 5 batteries chained on a single inverter.

One issue you probably will encounter is that when one battery in the chain is full or empty then the entire chain stops charging or discharging, so if you have significantly mismatched battery sizes you may well find that you don't get your full capacity. It might be better therefore to buy a couple of 5.12kW or a single 9.5kW battery and discard your 2.6kW batteries.
Also the 2.6kW batteries are limited (I think) to 1.3kW discharge rate whereas the others are not. Probably got that rate wrong but I know it is a lower limit

geoffreycoan Also the 2.6kW batteries are limited (I think) to 1.3kW discharge rate whereas the others are not. Probably got that rate wrong but I know it is a lower limit

I think all the batteries are limited to 0.5C. But it only matters if that limit is lower than the inverter's battery interface rate limit. I assume that multiple batteries charge and discharge in parallel, so the rates add (ie 2 x 2.6 can operate at 2.6kW)?

I had a Gen 3 HY inverter with 2x5.2 Gen 1 batteries...Then 3 weeks ago I had a Gen3 5.4 battery fitted...The installer had to put the Gen 3 battery first in the chain i.e. direct to inverter followed by the original Gen 1 (Primary - now Secondary) and other Gen 1 battery (now tertiary) - all done with extra cables. Also - and this is important..at the same time, I updated the three batteries with latest firmware (3022 for Gen 1 batteries and 4010 for the Gen 3) The installer then re-commissioned the whole set up..and after a hick-up..did a full SOC discharge and charge to get it all sorted. All good now

Thanks all. Based on the answers I'm going to push back on the original supplier. I think they're trying to push a load of new batteries to replace batteries that are still in support and I'm still paying for! I just want to add some capacity.