Field box battery charger converted from phone charger?

[dirkyboy098]

I have the standard 12volt gel cell field box battery.. but I dont have a charger for it. I have a wall charger from an old phone that sais it produces 12v output and 1amp. The field box battery is 12v but 7amp. Can I use the wall charger to charge the field box battery if I soldered gator clips without creating a problem? such as a blown up battery... :D does amperage create anything dangerous? I know this is a lame Newbie question but I miserably failed electronics in high school and your wisdom is appreciated.

thanks

[Daniel7866]

Hi,

You need at least a 13.8v regulated voltage (better curent limited) to safely charge this battery. The battery will normally self regulate the current. Even if the no load output voltage of your charger is 13.8v~14.2v the starting current drain of a 7Ah empty battery is higher than 1A.
Take a look at http://www.rcbatteryclinic.com/ for more information.
A possibility is to charge your battery via the cigar lighter of a running car.
Respect polarity. Some early vehicles (Mini Morris) were positive to ground :eek: .

Hope it help,

Daniel