question

landslide avatar image
landslide asked

Using a charger on a solar system

Hello! Total solar beginner here, but somewhat knowledgeable when it comes to 12/24V systems.
I got a perhaps simple question, but I have not been able to find the perhaps simple answer - so here goes:
I am looking at installing a cabin sized solar system with 2x100A lifepo4 batteries in parallell, 400W panels, mppt controlled and with a 1200W pure sine inverter.
Due to geographical location (Sweden) there is not much sunshine during the winter, and what sunshine there is can be somewhat limited in effect. Thus I want to be able to top up the battery bank using a petrol/natural gas generator from time to time running a Blue Smart 30A charger under generator power.

Can I just attach the charging leads to the battery bank and leave it at that while not charging using the generator?
Do I need to disconnect any other part/s of the system while charging using the generator?
Can I use the 12V system in the cabin while charging the batteries?
Should I disconnect the charger when not in use?

I know this is pretty much as basic as it gets, but the answer/s are not out there as far as I have found. Thus I am looking here. Having perhaps several inputs of power to the system at the same time (solar and generator) makes me wonder if the system is designed in that way.
I assume it is, but assumption has costed a lot of people a lot of money over time, thus I am asking.
I hope I have asked in a way that "make sense".

Regards!
L.




Generator
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2 Answers
JohnC avatar image
JohnC answered ·

Hi @Landslide

I think your assumptions are justified, multiple chargers are common, and don't need disconnecting if unused. At least for Victron kit.

Shame to run a genset though for a measly 30A @ 12V. It's an often overlooked aspect of design, and why a higher battery V, together with a inverter/charger is popular. Maybe for your future? :)

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landslide avatar image
landslide answered ·

Thanks for chiming in! Yeah, running a generator for 30 amps is a bit overkill, but that is pretty much the heaviest hitting charger I can find this side of my wallets limits. And I imagine that while I run the generator I can also take some time to make some coffee, do some vacuuming and some other stuff that requires 240V. So it will not be that often that I run the generator solely for charging.

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