I want to disassemble the 19.2 V rechargeable battery that fits into the Sears line of drills so I can replace the AA batteries inside. The battery cover is fastened by very small pin-socket-type screws (look like Torx socket heads but with a small pin in the center so one cannot get the Torx driver into the screw head).

I'm sure others have done this - what size driver do I need for this application? The screws are sunken into the cover so measuring them is next to impossible for me.

 

Buy a set of security bits...the hex type that will fit a 1/4 driver handle. I bought a standard set of the common sizes for around $6 or so ...can't tell you where. Harbor Freight, HD, one of those should have it.

 

Yeah, I didn't think HD or HF would have such specialty bits - I'll give them a try.

 

I bought my set at HF, I think I paid $3-$4 for it on sale [half price?] I've not looked but I would assume most other tool outlets would sell them too.

 

Rigid batteries use the tamper proof torque screws as well and as you describe, the access hole is rather narrow. I have a set of screwdriver style tamper torques I used in electronics that fit, but my standard 1/4" drive handle was too big and the bit wasn't long enough. Might take the battery with you to be sure you get something that fits.

Bud

 

I drilled the head off the screws with a regular drill bit. Then once the case was popped apart I was able to grab the remaining screw with a vise grip and backed them out.

 

My B&D/DeWalt batteries are glued together.

 

Ultrasonic welding is a PITA. I must admit that I have taken a saw to more than one battery pack to get it open. After replacing the cells I'm always amazed at how well quality duct tape or electrical tape can hold something together. The cheap stuff, well you get what you pay for, but a quality roll of tape can be worth it's weight.

 

They are also called insert bits, and you can usually find them in the screw bit assortment draws in the Hdw stores. I have several sears 18 volt drill batteries. Is it worth while to try to replace what looks like "C" size rechargable batteries, and where are they available?
Sorry to sort of hyjack this thread.
Sid

 

Just look online there are several sites that sell the battery cells. I have had ordered a couple times from All-Battery and have had no troubles.

Most recently I re-celled a couple battery packs for a portable DVD player and it was about 1/3 the cost of buying new battery packs. Usually I use the standard grade Tenergy cells and they have worked well and usually provide more capacity than the original cells in a pack. They also have a couple other "premium" cells that offer more capacity or a longer storage time with less self discharge but they cost a bit more.

 

I bought a set for $4.95 at HF and removed the battery cover. Unfortunately, the pack was composed of 16 sub-C NiCds and at $4 to $8 each and then having to futz around soldering and binding them together, the $60 price for a new 19.2 V battery pack makes sense.

 

What cells where you looking at that were $6 to $8 each?

 

Here's the link I was referring to: All-Battery.com - Rechargeable batteries & Chargers - Sub C (SC) Size Series Ni-MH Rechargeable Batteries

Rated at 2000 mAh to 5000 mAh, BTW.

Later on, I was able to find less expensive sources i.e. less than $3 each, but even at that price 16 for $48 plus I-don't-know-how-much-for-shipping-but-it's-gotta-be-more-than-$10-$15-dollars (they aren't light), and then having to connect them by soldering wires (I only have a 48-watt iron) and wrapping them with tape and cramming them back into the container etc. etc. I'd just a soon buy a new one (or two).

 

If it were just soldering wires not bad. But the ones I have looked at are all tack welded metal straps and trying to solder them where needed and hold the temperature down so as not to damage the battery is next to impossible.

I wonder what those batteries actually cost to make?

Bud

 

Generally it is only one or two cells that have died and need to be replaced. They are pretty easy to find, you just run the tool for a minute after fully charging the battery and then checking the voltage on each individual cell. The good ones will be about 1.2 volts and the bad ones will be less than a half volt.

Welding the tabs IS a problem, though.

 

I was thinking about first wrapping the 15 batteries (for the Craftsman 19.2v battery) with a couple rounds of clear shipping tape to hold them together, then solder wires to the ends of the batteries. But as I mentioned earlier, I only have a 45 watt (Weller, vintage 1970) iron and that won't generate enough heat to solder the wires to the ends without damaging the battery.

 

It's touch soldering to the ends of batteries no matter the wattage of your iron since the batteries ends are usually plated steel I think. I give the ends of the batteries a light sanding with fine grit sandpaper, apply a good dab of acid based flux and then solder.