Charge two solar generators from one array?

[jfm30204]

Noob question - sorry . A solar generator has a built-in MPPT controller and, I assume, certain protections. So my question is can you charge two generators from one panel or array without danger of shorting the them if both batteries are low so that both controllers are on at the same time?

 

[Crowz]

Nope. Mppt doesnt like the share. Sharing batteries yes. Sharing panels no.

Its not going blow up but its not going to work worth a flip either. Its just the nature of how the mppt controller works.

 

[Supervstech]

Noob question - sorry . A solar generator has a built-in MPPT controller and, I assume, certain protections. So my question is can you charge two generators from one panel or array without danger of shorting the them if both batteries are low so that both controllers are on at the same time?

What size SG?

 

[jfm30204]

Small. Two 300wh generators. Mostly camping or RV application. One or two 100 watt solar panels.

 

[stienman]

If you're using less efficient PWM charge controllers, then you can use multiple charge controllers off one string of solar panels. Your efficiency will probably be terrible, but if you're using PWM charge controllers then it's already terrible.

MPPT solar trackers are designed to actively interact with the panel and adjust their power conversion to maximize efficiency. This interaction means you can only have one charge controller connected to a set of solar panels.

 

[Supervstech]

Small. Two 300wh generators. Mostly camping or RV application. One or two 100 watt solar panels.

Those frequently have a 15V max input voltage… I use a single mppt controller to keep a house battery charged, and have cables tied to the house battery to charge my SG’S I often have three or four of em charging at the same time.

 

[jfm30204]

Thanks. Voltage of your house battery? Charging your SG's directly off of DC or AC through inverter?
I guess, then, if you had one larger SG, say 1000+ah, you could charge two smaller ones via the AC outlets on the larger unit. Inefficient, I know, but would it be possible, if absolutely necessary?

 

[Supervstech]

I jave a half dozen 300ish watt SG's and a 13.8V LFP house bank.
Tied directly to that are my SG charger cables.