Replacing cells in 41 battery pac

[Larry Wiese]

How do you split open the case on the 82120A rechargeable battery pack for the 41 series so that you can replace the cells? Does hair dryer help? Also, what are we now using to replace the half N cells?

[John Kercheval]

I would not suggest that.

You can buy full size N cells at Radio Shack and just put them in the standard battery holder. I've been doing this for years- longer life than a brand new Pac and cheaper.

The downside is that you must recharge them externally.

John Kercheval

[Larry Wiese]

I would do that if I had the "standard battery holder." Somehow it grew legs and walked away. Thanks for your response.

[David Smith]

I open my 82120's with single edge razor blades and a hammer. Gently tap the blade into the seam between the case halves. If you tap too hard the blade breaks... wear eye protection. If you slip your finger spings a leak... be careful. Some packs are much easier to open than others. I reseal my packs with IC2000 tire cement. This is a black, rubberized super glue that is made for gluing rubber tires to RC model cars.

As far as cells go you are probably out of luck finding the 1/2N NiCD cells. Sanyo quit making them over a year ago. TGWORKS (mentioned elsewhere on this site) is now out of business.

There are some 150mAH NiMH cells by Sanyo that are a close match in size. They are about 1/8 inch shorter than the NiCD cells, so you need to back them up with a small piece of wood. The 120mAH NiMH cells can be made to fit also, but they are quite a bit smaller in diameter.

[Larry Wiese]

Thanks alot for the information. I will give your method a try. Yesterday I replaced the drive rollers in two card readers and now they actually work! I didn't screw them up so now I will see what luck I have with the battery pack. Thanks again.

[Erik Wahlin]

David, Where do you get your NiMH cells?
Thanks

[David Smith]

Several months ago I found a place that had around 50 of the 1/2N cells in stock. I bought them all and had them wired them up into groups of 4. Unfortunately I have used them all to rebuild packs. They tried to find me some more but were unsuccesful.

It looks like it's NiMH time from now on. I have been unable to find another source for the 150mAH NiMH cells that TGWORKS sold. TGWORKS told me that they were Sanyo cells, but my Sanyo supplier could not find them in his catalog.