cordless drill battery

johndeere2210 · Jan 9, 2005

What is the best way to treat a cordless drill battery. I got a new Craftsman 18 volt drill/flashlight combo. Is it best to leave a battery on the charger and change it when the drill battery is discharged? I will only use the drill maybe 3 or 4 times a month this time of year. Useage will increase when the weather warms up. What do you guys do?

MikePA · Jan 10, 2005

and change it when the drill battery is discharged? 
Changing the battery when it's discharged seems like the right time to change it. Makes it kinda hard to use the drill otherwise. /forums/images/graemlins/tongue.gif

I have one battery in the drill and one in the charger all the time. After I use the drill, I swap the batteries, so there's a fully charged battery in the drill at all times.

My Owners Manuals indicate that it's OK to let the battery in the charger. What does your manual indicate?

JDgreen227 · Jan 10, 2005

I've been using cordless drills and saws since 1989 and if your charger is the type that will charge the battery in one hour or less, it's quite safe to leave a battery in it all the time. Such chargers have a "trickle charge" that keeps the battery on a full charge. My most-used cordless drill is a 1996 vintage 14.4 volt Dewalt and the batteries have been left in the charger whenever they are not in the drill and they still work fine.

Some cordless tools use a cheap charger that is just a transformer that fits on the end of the battery and they are to be removed at the end of 3-4 hours...don't leave that kind attached to the battery any longer than is required to charge it as that will shorten the service life badly.

Most new cordless batteries need to be discharged and recharged a few times before they will accept a full charge.
Some people say it's best to run them completely down before recharging and others say you should recharge when performance starts to decline but I have never noticed the difference no matter which method is used.

Soundguy · Jan 10, 2005

It's the older nickle cadmium that get the memory effect. nowadays.. just about everything is nickle metal hydride.. or lithium ion. The NIMH do fine with intermittant / incremental charge.

Soundguy

Bird · Jan 10, 2005

This post just reminded me that I left a battery in the charger day before yesterday, so I just now took it out. /forums/images/graemlins/laugh.gif However, my Makita is one that will charge the battery in an hour or less and it's supposed to be safe to leave one there all the time. I normally keep both batteries charged and in the case with the drill, and recharge after each use, but of course I don't really know that's the best way; just that it's worked for me.

bczoom · Jan 10, 2005

( ( I got a new Craftsman 18 volt drill/flashlight combo. )

I have the same thing but a couple years old. If I recall correctly, it said to fully discharge the battery before re-charging. Not sure what the new ones say.

A couple other notes.
It is best to put a cold battery in the charger. Allow the battery to sit for awhile after use before putting in the charger.

If you do leave it in the charger, make sure it is plugged in. I've found that if you leave it in the charger while the charger is unplugged, it'll discharge the battery.

btolle · Jan 10, 2005

I have 3 Craftsman cordless drill/flashlight combos. When the battery in the drill (#1) slows way down I take the one from the flashlight (#2) and put it in the drill and. When battery #1 is recharged I put it in the flashlight. Since I don't use the flashlight that often that battery is usually pretty well charged.

When charging I leave the flashlight (sans battery) on the workbench to remind me to take the battery out of the charger when it is charged. At my age I need all the reminders I can get!

Bill Tolle

_RaT_ · Jan 10, 2005

Check out this site. If you don't care to read it all, scroll to the bottom. Here is a little excerpt from it.

"Myth 1. Batteries have a memory effect. For some time, tradespeople have passed along the myth that battery packs must be fully drained before recharging. Goger says that “memory” myth is based on cordless tools in a previous era. “Back in the '80s, it was possible to inadvertently limit battery capacity by methodically using a tool and draining the battery the same way over and over again,” he says. “Battery memory isn't an issue today because technology has improved and tools are used for a greater variety of tasks.”"

Taking Charge of Your Cordless Tools

texbaylea · Jan 10, 2005

The latest issue of Wood Magazine (Feb/Mar) has a review of 14v cordless drills. There is also a very good discussion on the battries. It does demolish the 12 myths of batteries. This issue is not up on their web site yet www.woodmagazine.com yet.

Vernon

Soundguy · Jan 10, 2005

( If you do leave it in the charger, make sure it is plugged in. I've found that if you leave it in the charger while the charger is unplugged, it'll discharge the battery )

I'd say that you have a defective charger then. Like a shorted or leaky diode... (avalanching prematurely)...

In normal situations.. that diode(s) shouldn't reverse conduct at the voltages these battery packs are charged to.

Soundguy