Speaking of Gel-Cell Batteries...

[DouginUtah]

Rather than hijack the current 12 V. battery topic (pun intended), I decided to ask this question in a new topic.

I have a break-away setup on my trailer with a small gel-cell battery which applies the brakes when the pin is pulled.

This has never been used   but I am wondering if the battery needs to be recharged periodically (annually) or if the gel-cell holds a charge for a long time. How do you tell when a gel-cell needs recharging?

-Doug

[Tom]

It may get trickled by the light circuits from the pulling vehicle.

[moosehunter]

It should get charged by the vehicle when in use. You should have it tested once a year or so to make sure it is ok.

[DouginUtah]

Well, I wired the setup so I am pretty sure it is not connected to the light circuit. Maybe it should be, but it isn't. Anyhow, I haven't used it with the lights on in the past year.

Who can check it? I mean, it's not like a wet-cell that you can use a hydrometer on. How about I put a 2 amp trickle charge on it for 12 hours--no problems?

-Doug

[Ianab]

Hi Doug
All batteries will loose charge over time, the gel cells are about the best for holding onto charge, but topping it up with a small charger is a good idea.
The battery should have an Amp/hour rating on it someplace. This will give you an idea of how fast / long to charge it from flat. If it says 10 amp hours capacity it should take about 12 hours at 1amp to recharge, or 6 hours at 2 amps etc. A 2 amp charger shouldn't hurt it, just keep an eye on temp and if you have a meter stop when it gets up to about 14 volts.
To test the battery hook up a small load, like a 12v tail light and run it for a hour or so. If it does this then it's OK. If it dies after a few minutes the battery is stuffed. Then just top it up on the charger again.

Ian

[Stan]

You can get some idea of how the state of charge is by checking the voltage. A fully charged 12 volt battery will show something like 13.8 volts. If it has just finished charging you'll get a "flash" reading of 14.2, but that won't last long.