Hi, We are looking to add 24Kw of battery to a large house ,the system is retro fit so will be ac coupled inverter( AC3) as its also 3 phase
The AC inverters range from 5-12Kw
My question is, is there an optimum size of Kw inverter for that amount of batteries or is it purely what the demand may be on the house.
Many Thanks
24Kw of Battery
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Dave Foster
- Posts: 1256
- Joined: Thu Oct 13, 2022 7:21 pm
This can be quite a complicated answer as it depends on which batteries you will have - it all comes down to the battery voltage of the battery stack you will have and the maximum current the batteries can supply.
But that said a 24kWh battery is a reasonable size (if I do the maths on the ECS4100 batteries) you will have a stack of 6 batteries, a voltage of around 340V and a recommended discharge current of 35A which is 11,900W (V*A=W).
In that respect your batteries would be able to discharge at nearly 12kw (inverter willing) and so the main take away here is that you won’t be power limited by the batteries. In which case you should work out what your maximum concurrent house demand will be and get the inverter that fits that best.
The only other thing to add, is the maximum rate the batteries can be charged at will be your inverter limit and so if you were to have a 5kw inverter your batteries would charge at a maximum 5kw, a 7kw inverter would be a maximum 7kw etc…
But that said a 24kWh battery is a reasonable size (if I do the maths on the ECS4100 batteries) you will have a stack of 6 batteries, a voltage of around 340V and a recommended discharge current of 35A which is 11,900W (V*A=W).
In that respect your batteries would be able to discharge at nearly 12kw (inverter willing) and so the main take away here is that you won’t be power limited by the batteries. In which case you should work out what your maximum concurrent house demand will be and get the inverter that fits that best.
The only other thing to add, is the maximum rate the batteries can be charged at will be your inverter limit and so if you were to have a 5kw inverter your batteries would charge at a maximum 5kw, a 7kw inverter would be a maximum 7kw etc…