Charging a sealed gel battery

Factual Questions
1

I have the following battery:

I recently dropped and broke the 12v trickle charger i was using to keep it charged. I have a sh*tload of AC Adapters ranging from 3v to 25v, with every increment in between. I’m wondering if i can use a 12, 14, 15 or 16v ac adapter to keep this battery charged.

Thanks

james

2

You can “float” charge a Lead-acid battery at 14v. It’s not the optimal way to charge it, but it won’t damage the battery.

3

I don’t know if you just can go by the voltage on the adapter. When I’ve measured them using a voltmeter, the no-load voltage is higher than the rated voltage. I’d think you would need the no-load voltage to not be too high as well. Maybe they’d be OK, but you’d want to know before trying it, I’d think. Someone here probably knows the answer to that concern.

4

This is exactly so. A 12VDC adapter may have a on load voltage of 14-15VDC. So moving up to the 14V adapter to charge a 12V battery may be too much. I would start with the 12V adapter and check the voltage while charging. If it will take the battery up to 13-14V under charge, that would be the charger to use. I’d be against leaving any of these “dumb” chargers running continuously without checking with a multimeter. When the battery is charged, remove the charger.

5

A proper charger is going to have much better voltage regulation than your typical wall wart and also isn’t going to overcharge the battery. A wall wart will work in a pinch, although I’d recommend adding a series resistor to limit the current. Otherwise, the natural charging current at whatever voltage your wall wart puts out may end up being more current than your wall wart can safely supply.

Overcharging is going to shorten the life of the battery, so as Al Bundy said you’ll definitely want to remove the wall wart as soon as the battery is charged.

You’ll probably end up shortening the battery’s life by quite a bit.

6

overcharging is very easy to do and will ruin the battery. to prevent that you would need to monitor the battery charging with meters which takes lots of time. smart (nonovercharging) trickle chargers can be found for a few dollars (USA).