<< When I store my cordless drill, should I remove the battery from it, >>
Why wear out the latches and contacts prematurely? If the switch works properly
the battery is isolated. FWIW, I vote for leaving it on.
I disagree - most cordless drills use NiCad batteries which have memories so
should be drained before they are charged. Leaving the battery in the
charger will result in it being frequently "topped up" by the charger as it
naturally discharges and will reduce it's life and the amount of charge it
Leave the battery in the drill until it is almost fully drained.
I've had a cordless 12v DeWalt drill since 1998 and I have always left
the battery on when not using it. In fact, the battery stays on until
it is drained. The spare battery always stays in the charger which is
plugged into the wall. Not sure if this is good or bad but it is what
I have done. No worries so far.
PS -- Still using the same 2 batteries that came with the drill and
I've used (and abused) the drill quite a bit for driving deck screws
and making holes.
email@example.com (TOM KAN PA) wrote in message
Keeping it attached should not result in any drain, so it
doesn't make any difference if the pack is attached or not,
unless you have some light or electronic readout on all of
And the saying is six OF one and half a dozen OF the other.
The preposition TO doesn't make sense.
Seriously, leave them attached unless instruction for that
particular brand say otherwise. Even cheap batteries don't
discharge that rapidly. OTOH, the tendency for many home
owners is to ignore the batteries which sit for varying long
period and just die. Or, they let them sit, and then charge
them for long periods (forget them) and way over charge
them, damaging the battery pack. If you have a precise up
to date well controlled charger, you can just let them
charge, but most chargers are not that good. The best bet
is a maintenance program whereby you check the voltage of
the pack periodically and when it reaches a certain point
you recharge the pack.
Forget all the stuff people tell you about memory and
discharging the battery pack. You should never discharge
the pack below 1 V per cell or you are likely to damage it.
And a cycle is a cycle and a battery pack has only a certain
number of cycles in it, so don't every discharge just to
discharge; discharge because you are using it and don't let
it get hot. Remember; never less that 1V per cell. In
practice, that number should be much higher and could be as
high as 12V. When you tool is getting obviously getting
weak, check the voltage and that is the voltage that you
don't want to go below.
The biggest problem with battery pack is overcharging, heat
kills quickly. So if your instructions say to fully charge
in 4 hours, never charge more than that, and if you use the
tool only a little and want to recharge, recharge for only
an hour or so. Check the voltage after the pack sits unused
for several hours and charge some more if needed. A fully
charged 12V pack probably reads around 13.2 volts. Check
the battery pack every month and charge it. You should
charge about once a month if you don't have and accurate
trickle charger (and most aren't accurate). Good Luck, and
if you need more information just do a google search on
Battery Memory and only read the ones that are from
universities, Government (e.g., NASA), or battery
manufacturers. Good Luck.
Don't think I understand that. In storage, the pack
constantly loose voltage through internal discharge. My
understanding is that as they go below 1v per cell, the
weakest cell is likely to reverse polarity and that will
ruin the battery. I keep mine charge above 12v by checking
every 4-6 weeks and charging before they drop below 12v.
I do the same with my lead acid batteries and charge them to
12.7v and while in storage charge them whenever they drop to
12.5v and never let them drop below 12.2v.
mark Ransley wrote:
On Thu, 27 Nov 2003 01:38:11 GMT, "George E. Cawthon"
If you are talking about a NiCad battery being stored for a month
or more it is best to leave it in a some what discharged state. 40% of
its full charge is usually recommended.
A combination of constantly topping it off and not using/discharging
will ruin the batteries life quickly.
Forty percent of full charge puts it below 1V per cell,
which will result in a good chance that the weak cell will
reverse polarity. That will kill the pack or lead to early
For example, a 12V pack that measures 13.2V at full charge
will measure 5.28V at 40% charge, which is extreme. I just
checked two pack and one read 13.05 and one read 13.11 after
sitting for at least 10 days. My packs don't lose enough
voltage to require a charge more often than once every 30-45
days. That is constant topping off. In any case, topping
off isn't destructive, it's overcharging
Topping off the battery, if you mean charging to its full
capacity but no more, isn't going to ruin a battery. In
fact, that is exactly what the best chargers do. And not
using/discharging it won't ruin it quickly either. Not
using it does ruin batteries if you mean leaving it alone
because when internal discharge goes below 1V per cell, a
cell is likely to reverse polarity. All of my reading and
my limited experience of nicads (about 10 years) indicate
that overcharging and deep discharging (anything below 8V
for a 12V pack) are the main culprits for ruining battery
packs. I've found that individual AA cells used in walkman
type tape machines that discharge to about 1.25 V and then
are removed and continue to discharge to less than 1 volt
have very short lifetimes and successful recharge cycles.
Good luck with your 5.28V storage of 12V packs.
I didn't say 40% of its voltage. I said 40% of it's full charge.
For a typical 10 cell 12v NiCad that would be around 9.5v.
First off AA cells for Walkmans are probably NiMh cells.
NiCads are different. I'l quote a statement on NiCad
battery care for a Skil cordless drill...............
"If you anticipate long periods of (i.e. a month of more)
of non use of your tool, it is best to run your tool down
until its fully discharged before storing your battery pack."
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