temporary solar install

[arjand]

Hello! I bought 60W panel with MPPT and need a temporary solution before figuring out final set up. There is a 12V cigatette lighter socket in the cockpit. Can I plug in the solar panel into that 12V socket to keep the batts up or am I playing with fire (literally?) as it goes through switching panel etc.

The wire going from the switching panel to the socket is 16AVG. I would keep the battery combiner on to keep both house and starting batts charged. House bats are two flooded 6V 360 Ah and the starting battery is a standard 12V starting batt (not flooded). Panel is a Lensun 60W and the MPPT is a Genasun.

I appreciate your thoughts!

Warmly, Ari

[a64pilot]

That will work, it’s only about 5 amps, and I’m sure the circuit is protected by a circuit breaker?

[smac999]

you will have big looses. but it'll work a bit, and be safe. just make sure power remains on at the plug. IE if you turn off the plug breaker, or the battery swtich. the panel will be directly feeding loads which is not good. which is why normally solar would be direct to battery. so it can't be turned off.

I would not combine the batteries. if that is your only charging source. I would not trust it to keep up with loads, which means you could drain the engine battery as well. as long as you are running the engine every month or so. there should be no need to charge the engine battery.

[a64pilot]

I don’t understand the panel will be directly feeding loads?
Will you explain?
It would just be an open circuit wouldn’t it?

[atoll]

Originally Posted by a64pilot

I don’t understand the panel will be directly feeding loads?
Will you explain?
It would just be an open circuit wouldn’t it?

if the battery switch is off,and the breaker to the cigarette lighter socket is ON with the panel plugged in.
it will supply power to any other breaker that takes its power from the common positive from the battery switch,if the panel is putting out current.

[a64pilot]

Ok, now I understand.
What he was proposing is very often done on cars for storage etc, except of course there is no battery switch there.

[Dymaxion]

Youre keeping the system longterm so why not locate and install the controller in its final position and wire it up to the battery directly. Wire it to the starting battery and youll be able to start engine and then via battery selector recharge your house battery. But if its your house battery that will get run down frequently then connect controller to it. I wouldnt run it to both batteries. You could kill both batteries during a cloudy week. You can sort out where to permanently mount you panel at your leisure.

[hellosailor]

"What he was proposing is very often done on cars for storage etc, except of course there is no battery switch there."
There is, sorta. A lot of cars have the ciggy lighters go dead when the ignition has been turned off, so the lighter sockets are physically cut off from the battery, although they are still connected to random other devices.
Some solar "maintainers" now plug into the ODBII port instead, because that usually has both direct and switched lines to the car battery.
FWIW.

I believe the small Genasun controllers have diode(s) in them, to prevent a battery from backpowering them and going dead when the panels have no output. That should be checked with Genasun for the specific model.

Personally I'd stick big alligator clamps on the output cables, and just hook the Genasun up directly to whichever battery bank I wanted to charge, eliminating all the potential "What if"s that come with whatever previous owners might have done to the wiring.