Hi I had a kh10.5 inverter along with 7 eq4800 batteries installed yesterday and my installer had set the battery max charging current to 32amps as requested, and I've seen it's still set at that in the inverter settings, but when I look at the detailed parameters on the app it shows 50amps and when the battery was topped up last night the inverter was drawing the full 10.5Kw from the grid. Can anyone advise how I can remedy this,
is there another setting that has been forgotten?
Thanks
Max charging current
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Dave Foster
- Posts: 1328
- Joined: Thu Oct 13, 2022 7:21 pm
The detailed settings are showing what the BMS is allowing the maximum to be set to - this changes with state of charge and temperature.
But if you have set a maximum DC charge current in the inverter settings then it will not be able to charge any higher than that irrespective of what the BMS would allow.
If you have 7 EQ4800 batteries, the battery voltage will range anywhere between 284V and 361V (10%-100% SoC)
Power = Volts * Amps so with 32A charge current you will have a charge current range of between 284V*32A = 9,088W and 361V*32A = 11.552W
But as already mentioned the BMS will start to very gradually reduce the charge rate above 80% SoC (see attached) so your maximum charge rate will be where it crosses on that graph - on your battery stack that will occur around 350V hence in practice 11.2kW is the maximum you will see which will be capped at 10.5kW as that is the maximum your inverter can handle.
If you want to limit your battery charge to (say) 6kW then set the charge current to 18A which will give you a charge rate of between 5.1 and 6.1kW as the battery charges.
But if you have set a maximum DC charge current in the inverter settings then it will not be able to charge any higher than that irrespective of what the BMS would allow.
If you have 7 EQ4800 batteries, the battery voltage will range anywhere between 284V and 361V (10%-100% SoC)
Power = Volts * Amps so with 32A charge current you will have a charge current range of between 284V*32A = 9,088W and 361V*32A = 11.552W
But as already mentioned the BMS will start to very gradually reduce the charge rate above 80% SoC (see attached) so your maximum charge rate will be where it crosses on that graph - on your battery stack that will occur around 350V hence in practice 11.2kW is the maximum you will see which will be capped at 10.5kW as that is the maximum your inverter can handle.
If you want to limit your battery charge to (say) 6kW then set the charge current to 18A which will give you a charge rate of between 5.1 and 6.1kW as the battery charges.
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Thanks I naively thought it would be 32a x 240v. I'm on a looped supply and have permission to run my ev charger so my thinking was, as I can't do dynamic load management of the inverter drawing power, I'd cap it at around 7-8Kw as the dno are happy for that draw for prolonged periods from the charger
Just wanted to add that reducing the amps to 20 did indeed work and charged at around 6.75Kw
Just wanted to add that reducing the amps to 20 did indeed work and charged at around 6.75Kw