Can I use a (Marine?) Switch to charge controller vs AIO Unit?

kjswiley

Solar Enthusiast
Joined
Jan 11, 2022
Messages
66
I do not want to own a generator due to storage space and risk of theft, but when my batteries get too low my AIO unit shuts down, and then I do not have the juice to turn it on to charge my batteries up via solar the next day when the sun comes out. Can I buy a basic (48V) charge controller and use a switch so that I charge the batteries via my panels. I do not need to power anything at this stage, I just want to charge them enough so I can then switch to the AIO unit. Assuming I can do this, what do I need to be careful of, and anyone have a charge controller they recommend for this? As you can guess I killed the batteries last night, so now I get to tear my trailer apart to get to them, undo the wiring so I can wire them up to parallel and charge them via my neighbors power (I do 4 at a time), which is less than ideal for an off grid system.

I have the Growatt 5000 ES, and 2 sets of 4-12V batteries wired in series/parallel, is that 4S2P?

Thanks!
 

kjswiley

Solar Enthusiast
Joined
Jan 11, 2022
Messages
66
I believe that unit can still charge when in standby/off:

View attachment 98529
Oh wow that would be great, I couldn't understand why it wouldn't do that...I will need to take a look at it tomorrow to figure out what I will need to do, this is not the 1st time I have unhooked and charged the batteries via the method I described! I think I just needed to switch it off to activate standby mode, which I never tried. Thanks so much!
 
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Samsonite801

Photon Sorcerer
Joined
Oct 15, 2020
Messages
1,862
...and then I do not have the juice to turn it on to charge my batteries up via solar the next day when the sun comes out.

Are you on-grid or off-grid? (my assumption based on your description was off-grid since you mentioned generator and not grid)

What is the battery type / chemistry? How low SoC (or voltage) are you taking them down?


Can I buy a basic (48V) charge controller and use a switch so that I charge the batteries via my panels.

You can add in a standalone charge controller in parallel, you don't need a selector switch for it (they can both charge on same battery bank at same time), but if the battery is super low on juice, that charge controller likely won't turn on either.

Or were you meaning add in an AC powered battery charger in parallel? If so, you can do that too without a selector switch too.

I have an MPP Solar LV6548 AIO setup I will be using, and since it can only AC battery charge (off gen or grid power) while in standby mode, I bought separate AIMS 48v battery chargers to plug into the battery bank (no selector switches needed), in case I wanted to use aux AC power source to charge on my bank while the inverters are turned on.
 

kjswiley

Solar Enthusiast
Joined
Jan 11, 2022
Messages
66
Are you on-grid or off-grid? (my assumption based on your description was off-grid since you mentioned generator and not grid)

What is the battery type / chemistry? How low SoC (or voltage) are you taking them down?




You can add in a standalone charge controller in parallel, you don't need a selector switch for it (they can both charge on same battery bank at same time), but if the battery is super low on juice, that charge controller likely won't turn on either.

Or were you meaning add in an AC powered battery charger in parallel? If so, you can do that too without a selector switch too.

I have an MPP Solar LV6548 AIO setup I will be using, and since it can only AC battery charge (off gen or grid power) while in standby mode, I bought separate AIMS 48v battery chargers to plug into the battery bank (no selector switches needed), in case I wanted to use aux AC power source to charge on my bank while the inverters are turned on.

I am off grid, using LiFePO4. I do not recall what my battery cutoff is set at, but I adjusted the AIO to shutdown at 10 or 20% remaining to extend the battery life long term, so figure there should be enough juice to run standby, though perhaps that was reset last time I was messing with it as I read unhooking it for 30 mins does a factory reset...so maybe I took the batteries down to zero-which would explain no standby as well.

unfortunately they are very hard to get to, so I cant measure them with my multimeter until I tear apart my spare room full of junk.

I have the cheap CHINS running, so will need to look and see if there is an issue as I dont think I should be able to kill them in 1 evening with what I have running.
 
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