Good day everyone. I am new to this forum and solar. I have gone totally off grid. No Eskom.  System is as follow. 5KVA Schubart axpert inverter, 6 x 360 watt panels, 3Kwh Schubart Lithium battery. Will add 3 more panels and 1 x 3kwh battery later on.

My question is, i bought a Honda FA 2500 FMH generator to charge my lithium battery for those rainy days. I only manage to charge my battery at 8 Amps with the generator . Inverter is set to charge at 20 amps.

How can i increase the charging current? also my generator charging at 8 amps struggle to charge my battery above 50.8 volts. Float level 54 volts.

Thank you

8A at 220V is about 1800W, which is close to the capacity of that generator. 

1 hour ago, Kevin Sheasby said:

FA 2500 FMH

(No Losses taken into consideration)

That rating might be 2500VA that roughly relates to 1900 watt, so your 8 amps on 230Volts is 1840 Watts. 1800Watt / 54 volt is 33.33 amps you have available for charging the batteries. But then you need to supply the load as well. 

I guess the only way to get over the 50 volt mark is to charge the batteries for longer.

What is the max charge current allowed for your specific battery?

 

1 hour ago, Kevin Sheasby said:

I only manage to charge my battery at 8 Amps with the generator . Inverter is set to charge at 20 amps.

Please check your settings? 

Axpert has 3 settings, DC charging amps, AC Charging amps and Combined charging amps.

If the AC charging amps are set to low, it will also limit the charging current. 

What is the load at the moment when you only charge at 8 amps? The inverter will try and supply the loads first, taking away some of your generators capacity and only the surplus will be used to charge the battery. If this is indeed the case, A bigger generator might be needed. But please make sure about the figures first.  

You have to derate the engine power by about 10% as well for altitude.

Thank you for the quick response. My load is usually between 400-500 watts. Can i change the setting on the inverter  from AC charging amps to DC charging? How do i check and change the AC charging amps on the inverter?

 

Input on the inverter shows AC 230 - 240 volts when generator is connected.  Output 230 Volts on inverter.

3 hours ago, Jaco de Jongh said:

I guess the only way to get over the 50 volt mark is to charge the batteries for longer.

If it's a Lithium battery... it can take absolute ages for the voltage to rise 🙂

 

2 hours ago, Kevin Sheasby said:

Can i change the setting on the inverter  from AC charging amps to DC charging? How do i check and change the AC charging amps on the inverter?

Do you maybe have a pdf Manuel, or a link to one for your specific Inverter, From that I will be able to tell you where to look.

There are guys on the forum that knows the Axpert Much better than I do, maybe one of them will know the settings out of their heads. 

On 2019/10/17 at 12:26 AM, Kevin Sheasby said:

I only manage to charge my battery at 8 Amps with the generator . Inverter is set to charge at 20 amps.

Is that 8 A AC from the generator or 8 A DC into the battery?

The 20 A maximum charge current is battery current. So if you're only seeing 8 A DC going into the battery, that's only 400 W.

I think it must be inverter settings. If it tried to pull too much power from the generator, it would slow down and stall. You report 230-240 VAC from the generator, so that doesn't seem to be happening. The Schubart inverter may or may not be a clone (discussed here); clones can have quirky problems like this.

I think a float voltage of 54.0 V is quite high for a 15S lithium iron phosphate battery. OK for a 16S.

Thank you for the feedback.  My Utility charge rate was set to 10 A without me noticing . My bad. I've set it to 20A and charges wonderful. Everything runs smooth for now.