Attempting to provide AC charging through my 24v Growatt 3000w AIO

[OffgridMatty]

I have a 24v Growatt AIO inverter/charger connected to two EG4 Lifepower4 batteries in parallel. I have no trouble keeping them charged up in the summer, but winter is another story. My cabin in only used occasionally in the winter months and the system is turned off while away due to the batteries not being able to be charged below freezing. My Growatt has an AC input function, but I am not sure the requirements for that input. Last year I brought the batteries home to charge them a few times (that is a pain). I would like to charge the batteries from my generator at the cabin. Can I just connect a modified extension cord from the generator to the AC input on the Growatt? What would be the correct wire gauge if this is appropriate? I did purchase a charger from Signature Solar (battery charger), but that has not worked when connected to the system as a fault occurs in the Growatt. Thanks for any info on this situation.

 

[Crowz]

Actually it looks like the battery charger you bought should work. You just need to connect it to the generator not the growatt for charging.

 

[OffgridMatty]

It does work at home. When I connect the leads from the charger to the bus bar in my system the Growatt faults and alarms. Maybe a setting needs to be changed? Or do I need to disconnect the batteries from the Growatt to use that charger? I was hoping to have the inverter running while also charging.

 

[Crowz]

It does work at home. When I connect the leads from the charger to the bus bar in my system the Growatt faults and alarms. Maybe a setting needs to be changed? Or do I need to disconnect the batteries from the Growatt to use that charger? I was hoping to have the inverter running while also charging.

Well if it wont work with the growatt you will have to disconnect the batteries from it to use it. The generator can be used to feed the growatt but I think I remember a few post in here where the generator had to have a very clean output to work with them. Do a search to confirm that though.

 

[OffgridMatty]

I'm not sure if my generator is "clean" or not. It's a Honda eu2200i inverter generator.

 

[Crowz]

I'm not sure if my generator is "clean" or not. It's a Honda eu2200i inverter generator.

That's about as "clean" as it gets with that one. What model is your growatt?

 

[Crowz]

If your growatt is a SPF 3000TL LVM-24P for instance then yes you should be able to connect to the growatts ac input from the generator. Just make sure you use a large enough cord when doing this and don't max out the growatts output while charging the batteries since it is rated higher capacity than what your generator can produce.

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[OffgridMatty]

Yes that's my model. I'll create a 10awg cord and try that. Thanks for the help. I'll be up there after Christmas and give an update once I try it.

 

[Rednecktek]

10AWG should be fine and you can run the cord right into the AC In on the Growatt. With a 2000i you'll probably need to go into the settings and drop the AC charging amperage or you'll overload and trip the generator. You'll be maxing out at 60a (1800w) from that generator and IIRC the AC charging defaults to 80a. I'd set that for 50a and tweak up from there until your generator starts whining.

Another setting you might want to tweak (and I'd have to dig into the manual to find the setting number) is the AC charging voltage, or what voltage the battery gets down to before it kicks on the AC charging.

 

[OffgridMatty]

10AWG should be fine and you can run the cord right into the AC In on the Growatt. With a 2000i you'll probably need to go into the settings and drop the AC charging amperage or you'll overload and trip the generator. You'll be maxing out at 60a (1800w) from that generator and IIRC the AC charging defaults to 80a. I'd set that for 50a and tweak up from there until your generator starts whining.

Another setting you might want to tweak (and I'd have to dig into the manual to find the setting number) is the AC charging voltage, or what voltage the battery gets down to before it kicks on the AC charging.

Thanks for the additional information. I have the manual at the cabin and I'll adjust those settings and see how it goes. I can't wait to try it and hopefully get this figured out. I appreciate the help!

 

[OffgridMatty]

I had time to head to the cabin last week. The Honda EU2000i generator charged the batteries perfectly connected to the AC in on the Growatt. I used 10AWG wire with no issues. Charged at 30A and in 4 hours went from 47% to 85% on my 10 kwh lifepower batteries. I'm very happy with the extra piece of mind this provides with winter being a challenging charging situation.