Adding extra batteries to H1 system that already has 7 battery units in 1 stack

[solarmax]

Hi. I have 10x 405W panels, a H1-3.7-E and a ECS2900-H7 with 20.16 kWh total capacity. Is there a way to add additional storage? It seems maxed out with the 7 battery units. I'm in the UK. Is there another Fox ESS inverter I could replaced my existing inverter with to be able to add a second stack of batteries or is it possible to add a second inverter to my system with its own stack of batteries? Thanks

[Dave Foster]

7 * ECS 2900’s is the maximum for a single H series inverter.

Sorry the answer is now going to get a bit more complex, if you have the latest H1 (Gen2) inverter it allows parallel operation with another H1 (Gen2) inverter i.e. you could have 2 inverters with 2 stacks of batteries and they would manage the loads and the storage charge/discharge between them.

If you have an earlier H1 (Gen1) it doesn’t support parallel operation and you would have to replace it with a Gen2 (it’s a plug and play replacement) and then add a second inverter.

But if I throw another hang grenade in, you can replace the ECS2900’s on your existing inverter with ECS4800’s and with the ECS4800 you can have up to 9 batteries (1 battery and 8 slaves) i.e.43.2kWh of storage - that option is only possible with the ECS4800 batteries.

[solarmax]

Thanks. In the dual H1 gen 2 setup, does the size of the inverters need to be matched or can the be different size inverters? Also, same question for the battery stacks. Eg could you have the existing stack of ECS2900’s x7 and second stack of ECS4800 (eg x4 in that stack)?

[Dave Foster]

I ‘believe’ the answer is yes, but in all honesty i’ve never seen an install with 2 different sized inverters and 2 different sized battery stacks - probably one to fire straight to Fox… be grateful if you could confirm what they say so we know for sure.