Thread: Trailer breakaway battery - best way to keep it charged when not in use

I've got a Reece breakaway battery on the trailer I built earlier this year.

Like this one: https://trailercamperaustralia.com.a...50-85-320.html

Its got an inbuilt smart charger, so only needs a 12v feed from the tow vehicle to charge it. I've got it connected to the tail/position light circuit on the trailer so I always tow with the lights to keep it charged.

Last time I went to use it the battery was flat. Only been sitting for 4-6 weeks (its previously sat for longer and still been OK).
I'm not convinced the cheap Chinese battery it isn't dodgy, but aside from that I need an solution to keep it charged when not in use.

I can think of a few different methods, but has anyone got a simple working solution for keeping these things charged?

Steve

I have a Century Battery charger, that can be left in maintenance mode indefinitely mate uses one on his boat. I purchased mine from Battery World.

A general suggestion and what I do with all my 12V batteries that need periodic or occasional charging is to install an easily accessible Anderson plug. My battery chargers terminate with a Anderson plug, as do my portable solar panels, so at charging time there's hardly any stuffing about undoing straps, opening battery boxes or reaching in to access hard-to-get-to terminals. Also, there's no risk of alligator clips popping off, which used to happen from time to time.

Don't test it is what I do.

Hi Steve, I'd be inclined to install a small 10watt solar panel to say a tool box, or somewhere there will be constant light getting to it, when you get around to installing the winch, connect it to both batteries to top them both up.
Failing that install a Projecta charge n maintain, that will keep the battery charged all the time.
My Brother has one connected to each of his Harley and Kawasaki 900, to keep them topped up.
https://www.projecta.com.au/categori...rge_n_maintain
Kryn

Originally Posted by KBs PensNmore

Hi Steve, I'd be inclined to install a small 10watt solar panel to say a tool box, or somewhere there will be constant light getting to it, when you get around to installing the winch, connect it to both batteries to top them both up.
Failing that install a Projecta charge n maintain, that will keep the battery charged all the time.
My Brother has one connected to each of his Harley and Kawasaki 900, to keep them topped up.
https://www.projecta.com.au/categori...rge_n_maintain
Kryn

With the small solar panel I think that you would need a solar charge controller to control the charging otherwise you are likely to kill the battery by overcharging it and boiling it dry. Victron make a range of pretty sophisticated charge controllers and other solar related equipment, it is mostly expensive, but pretty highly regarded in RV and Marine circles, and there are also other less expensive brands, some of which also seem to work well. For what it is worth Victron also have a lot of info online, as I imagine other manufacturers would too.

The breakaway unit has an inbuilt bulk/float charger, so I’m thinking if I connect a small solar panel to that input it should be safe enough from overcharging.

Currently that charger input is
connected to the tail/position light power, so if I just splice the solar panel in it will run the lights too.

Thinking that if I also put a diode between the splice point and the tail light feed it will stop the solar powering the lights, but still allow the power from the light circuit to get to the charger when driving.

Assuming the alternator is putting out ~14v then the ~0.7v drop across the diode will mean over 13v to the charger which should be enough to keep it charged.

Anyone see a flaw in that plan??

Steve

Hi Steve, that should work fine.
Just make sure that the diode is facing the correct way.
Kryn