Maximum charging current parameter 2 setting please 5kva 48v inverter 

1x 3.5 and 2x 2.4 pylontech lythium batteries, current setting is 30A, was the setting with only the 2x 2.4 batteries, does it needs to change with the added 3.5 kwh? 

1 hour ago, MartinKoch said:

1x 3.5 and 2x 2.4 pylontech lythium batteries, current setting is 30A, was the setting with only the 2x 2.4 batteries, does it needs to change with the added 3.5 kwh? 

For 2 x 2.4 it should have been 50A (25A for each 2.4)

Now that you've added 3.5 Must be 80A (37A for each 3.5) Not 90A

Edited September 25, 20204 yr by Quwatush Shams (Suly)

Thank you, I can only select 20A or 30A, thus either 60 or 90 combined, will 60A be better? 

20 minutes ago, MartinKoch said:

Thank you, I can only select 20A or 30A, thus either 60 or 90 combined, will 60A be better? 

The inverter setting is total charging current, not per battery.  So, you should set 80A - it will be divided by the BMS between the batteries.

13 hours ago, MartinKoch said:

I can only select 20A or 30A, thus either 60 or 90 combined,

Calvin is correct, unless you also have 3 inverters. But even then, you can set the inverter limits differently, e.g. 30, 30, and 20 for a total of 80 A.

Appreciate the feedback

Did set to 80A, very little knowledge of this issue, what is the benefit of correct setting VS for instance 30A? Quicker charging time, battery performing more optimally or what? 

1 hour ago, MartinKoch said:

Did set to 80A, very little knowledge of this issue, what is the benefit of correct setting VS for instance 30A? Quicker charging time, battery performing more optimally or what? 

The 80A is essentially the maximum recommended value.  If your batteries will charge fully at a lower setting, by all means use it.

Generally, lower current is better as the power wasted (because of the internal resistance of the battery) goes up with the square of the current.  This wasted power also heats the batteries, which is not a good thing.

 

4 hours ago, MartinKoch said:

what is the benefit of correct setting VS for instance 30A? Quicker charging time,

Yes. Quicker charging time is the main benefit. But it may also prolong battery life, as the battery can use more solar power (if and when available), so it doesn't spend so much time at very low states of charge (low SOC); low SOC is bad for nearly all battery types.

Also, the Axpert chargers use the value in setting 02 to determine the end of charge condition. With factory firmware, it's 1/5th of the value in the setting. If you leave this value too low, the termination condition will be very low (though the inverter has a minimum value for this, 5 A comes to mind).

Thanks for the feedback, will monitor charging time tomorrow, regards Martin 

Took basically just over three hours from 34% to fully charged, definitely faster, one more question please, I do have the Raspberry software, indicating 28 on battery temperature, that stlii low enough? Referring to Calvin's feedback 

1 hour ago, MartinKoch said:

indicating 28 on battery temperature, that stlii low enough? Referring to Calvin's feedback 

I think that 28°C is fine for the battery modules. Unless your total battery capacity is quite small relative to your needs, I don't think that the life improvement from charging slower would be significant.