Morgans wrote:
"Anthony W" wrote


Interesting stuff. A few years back I bought a cheap harbor freight 12v
cordless drill with an extra battery pack. Surprisingly the drill was
pretty good quality for the money but the battery packs were shot in a
week. Now the drill is still sitting around here somewhere and pretty
much useless. I was thinking about adding a long cord and a cigarette
lighter adapter so the thing could be used out and about rather than
tossing it. I'm considering fixing it now.


Two things to consider, here.

Cheap batteries, like you said. Probably very small capacity, too. Replace
them with the largest capacity batteries that will fit, if you go that
route.

Next, is that the charger is a cheap, no brain charger, and will happily
over charge your batteries, and charge your new battery to death.

If you don't have a smart, peak detecting charger from another drill or
power tool that you can rig a couple wires with alligator clips to, or slide
terminals (whatever will work the best with your cheap drill pack) you
should figure out what else you could do about charging.

If you have enough stuff you want to charge properly, you could get a remote
control car or airplane battery charger (a field charger that runs off of 12
volts is probably your cheapest good option) and charge all of your assorted
stuff with that. You know you are getting full charges, and not over
charges. You would have to make the call on whether it is worth spending a
fair amount of money on something like that.

Another fairly inexpensive option is to use the charger that came with it,
but add some "options" to it.

With the drill pack drained, put a volt meter in line, and check how many
milliamps the charger is putting out. As it is about half charged, and then
90% charged, read the milliamps again. That will give you some idea of how
much the charger is putting out on average.

Get yourself a 12 hour wind up timer switch, and make up a timed outlet to
plug your cheap charger into. You should then be able to make an educated
guess at how long it needs to charge, depending on how much you drained the
battery. You will need to put about 10% extra charge (when charging a full
charge time; pro-rate shorter times accordingly) into the battery, based on
straight capacity and charger output.

Note that this type of thing is not the best way to do things, but better
than killing new batteries with over charges. If you have a smart charger
around, adapt it to charge all of your stuff with dumb chargers.

Hope that is food for though. I need to rig up a new pack and alternate
charge method for a cheap drill, myself. It was so cheap I couldn't pass it
up! g


Cerainly food for thought, Morg.

Thanks a lot.

Richard