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HP41 rechargeable pack repair - Printable Version

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HP41 rechargeable pack repair - Giuseppe Marullo - 01-31-2004

I got a NiCd pack, almost surely dead. I would like to repair it, but I can't find a safe way to open it without breaking the plastic enclosing.

The same apply to doubling a X-Memory module, should I break the enclosing for sure (like Cristoph says in his book) using a knife, or a lower impact approach exists?

I have another repair to try, a card reader that works well, but one spring on the lock mechanism is not working.
Is it worth to try to repair or better to leave as is?

Giuseppe Marullo

Re: HP41 rechargeable pack repair - Paul - 01-31-2004

I have repaired several HP-41 battery packs. I have tried using an exacto knife and an exacto saw. In my opinion, the saw works much better and gives you a nicer looking finished product. I have refit the batteries with 1/3 AAA NiMH (nickel metal hydride)soldered in series. Glue the finished pack together with airplane glue. Paul.

Re: HP41 rechargeable pack repair - Giuseppe Marullo - 01-31-2004

thank you for your answer. Do you have any photo about the hack? I would like to see an example on how to cut it neatly, this things are not easy to find.

The same apply to the X-Memory modules? Do I need to cut the envelope, no other way?

Re: HP41 rechargeable pack repair - David Smith - 01-31-2004

I slice around the joint between the two case halves with a single edge razor blade. This can be rather difficult and time consuming (and a bit dangerous). A saw is easier but can remove too much plastic.

Re: HP41 rechargeable pack repair - Vassilis Prevelakis - 02-01-2004

Pictures shown the opening up of a memory module may be found at ji's web site:


I'd also use an exacto knife to create the line where
the two parts will separate (i.e. don't try to cut through,
just create a single continuous scar along the joint, the plactic will open up like a broken zipper once you apply pressure with the blade as shown in the pictures).


Re: HP41 rechargeable pack repair - Giuseppe Marullo - 02-02-2004

thank you about the link, I will try it. Thanks to Paul, I find the courage to open the battery pack, I will post photos this evening.
I am buying the 1/3 AAA 120mA/h batteries, since the 220mA/h I got are too big for the rechargeable pack, given I will keep original electronic and connector.