just learned something when the battery on things like battery drills go dead. when they are really dead they cannot take a charge. take your 12v battery charger from your car and connect one lead to one of the battery terminals and then just touch the other lead to the other terminal. do this until you get a spark, then put it back on the charger & it will take a charge again.

Makita batterys? I have 2 that are dead, they take a charge but dont have any power and a dead again in 30 seconds

the battery has 4 posts , two go to drill the other two go to the charger. Which terminals are you touching? I get no spark on the charging terminals, but do spark on the 2 drill terminals

Your trick didnt work on mine . I think they are just too old and need replaceing. Cheaper to just go buy a whole new drill set

the charging terminals

I think my 2 rechargable batterys are Kaput

My charger light goes green for fully charged but they last about 3 seconds on the drill

I do the same thing as butchloc, except I think I leave it hooked up for slightly longer, like 10-20 seconds usually. However, I will hold the battery in my hand and at the first hint of getting warm I'll cut the juice. Also, any sort of power supply will work.

What is happening is the NiCd cells will develop an internal short (think of tendrils forming inside the battery) and the burst of voltage will disintegrate them.

If you need to rebuild a battery pack and are handy with a soldering iron, often Harbor Freight will have a cheap extra battery for a drill for $10 or so, you can take the cells out and use them to rebuild your own battery pack.

Hey Butch, I just converted my old Black & Decker 12V Cordless to a 50' Extension Cord with Battery Clips a week ago.

I went through a number of Batteries for it and then it began Killing both the Battery and Charger together. Did that a couple of times. However, the Drill was in great shape and I didn't want to just toss it out.

Looked at the old dead Battery on it, and it has 3-screws holding the Battery housing together. Removed them, trashed the old internal batteries, drilled a hole through the end of the Base portion directly below the 12 V silk screen, ran the cord in, soldered in the leads from the "Female End" of a 16ga extension cord, and slid up the Shrink Tubing over the soldered connections. That Female Extension piece in the old Battery Housing is about 1' long. So I can half-hitch the Male portion of the Extension Cord to the Female portion prior to plugging them together. On the other end of the remaining 49' of Male Extension Cord are a couple of Battery Clips.

I went with the Female portion in the Battery Housing to prevent someone from accidentally hooking it to an extension cord plugged into a 120V outlet.

Now I can hook the 12V B&D to the truck battery, the mower battery or simply buy a new 12V Lawn Mower Battery(at less cost than the B&D 12V) and charge it with my regular Battery Charger.

Has plenty of power now and is still portable. Plus if I ever think I need to stick an original B&D Battery in it, I can just unplug the one I converted and plug in the new B&D Battery. But, I really doubt I will ever buy another B&D Battery for it.

I really should have done this when the first B&D Battery died.

quote:

Originally posted by Mark:

What is happening is the NiCd cells will develop an internal short (think of tendrils forming inside the battery) and the burst of voltage will disintegrate them.

Well not exactly, That may be true but What is most likely happening is the automatic battery charger has a voltage sensor in it and if it senses too low of a voltage it will not cycle itself on. Connecting the power supply tricks the charger into thinking there is a correct voltage present. Then it will charge until a maximum voltage is reached.

Now for the batteries that will no long hold a charge. They are done, Kaput, No good.
Nicad has a bad habit of developing a "memory"
What this is let say you have a battery pack and it's fully charged but when you use it you only use half the charge on the pack then recharge the battery. Well if you continue to practice this the battery will develop a memory of 50% meaning that you will no have a battery with 50% of the original capacity.
Nicads should be used up until they no longer power the tool they go to then let them cool and place on the charger. This will give you the most usable life from the battery.
NiMh and Lith Ion do not develop a memory and are there for better batteries to get for your tools but are much more expensive.

Kcstott, I have the makita nickel-cadmium batterys. The drill is several years old, and dont use it a whole lot so the thing is in real good condition. The drill always worked great

When I put the batteries on the makita charger it does not take very long before the green fully charged light comes on. I remember it used to take awhile to charge them. The batteries just dont even run the drill now when the charger says they are full. Just a couple spins and dead.

Are they just Kaput? I tryed the Auto Battery charger on the charger terminals but never got a spark. I didnt hold them on there very long

These bat packs have no screws to take them apart, looks like a sealed unit

Rick

Yep afraid so. Nicads also don't last forever either. At most you can expect about five years of good home use or about two years industrial use at best.
You could try connecting them to a low amperage (1 amp or less i.e. 500 milli amps) power supply and letting them go over night. Some times this can condition them to get a bit more life out of them but if you have a bad cell then it won't work. And unfortunately you'd have to buy a new pack if available from makita as taking yours apart is a no go

Its more than 5 years

regular drill and extension cords

Yep unfortunately they don't tell you the batteries have a shelf life.

Do what I did. Buy a generator and use corded tools. They are more bad ass anyway, and now you have a generator.

quote:

Originally posted by GSP7:

regular drill and extension cords

I am always amazed how my 15 year old $19 regular drill always seems to work better than any of the cordless drills that I have had.

The problem with cordless tool is you have to spend a fortune to get on that will compete with a with a corded drill. My XRP DeWalt will hold it's own till the battery goes dead
But at $300 new it damn well better