On Oct 5, 6:09 am, Paul Franklin
wrote:
On Fri, 05 Oct 2007 03:12:21 -0500, wrote:
I have one of those cordless drills that has a 24 volt battery. I was
wondering what would happen if I unplugged the charger from the wall,
and left the battery in it. Will the charger discharge the battery if
I dont pull it out of the charger?

Also, someone gave me an 18 volt drill that has the identical looking
battery, except the battery is an 18 volt, not a 24. That drill did
work when he gave it to me, but his charger died, and he just bought a
new drill. Can I plug that 18V battery in the 24V charger or will I
damage the battery? It does fit into the hole on the charger. I dont
think 6 volts is that much different, but it may be for the battery.

GMU

Remove the battery from the charger if you are going to unplug the
charger. Whether or not the charger will discharge the battery when
the charger is unplugged depends on its design, but why take the
chance?

Don't use a 24 volt charger on an 18 volt battery unless you want to
ruin it. Note that some chargers are designed to be able to charge
several different voltage batteries. But if it doesn't clearly state
on the label or in the instructions that it can do this, don't do it.

HTH,

Paul F.

Old chargers or chargers that dont measure the limit of the battery
ruin batteries by slowly cooking them. Most all chargers now made
measure the peak voltage of a battery my monitoring just when the
volts drop or temp rise, I guess shuttng off at a certain temp. If the
charger measures temperature it should work, if it measures a voltage
drop other than 24 it should work, if it goes by 24+ v it wont.
[Actualy it might be near 28v ] My new 12v Ridgid charger does 9.6.12
and 18v . If you know the + and - leads and hooked up a digital V
meter to it while the battery was charging and measured the charge you
could see if its ok by what happens. The 18v should peak higher than
18v [near 20v] and the point at which the voltage actualy starts to
drop, indicates full charge, that is also the point at which battery
temp rises. At full charge you must stop or the battery cooks itself
by converting the energy into a mechanical energy, raising its temp.
You can use a higher v to charge, you just have to know when to stop.
A 1.2v nicad is fully charged at maybe 1.36v. So if the 18v is 15 cell
you need more than 20v to charge it.