HP-32E Battery Pack



#2

I'm new to this board. Have an HP-32E that I love, and am hoping to salvage. The battery pack, now for the second time, does not hold a charge for very long. Lats time, I was able to buy a replacement pack by mail, although I can't remember where. This time, I went to Radio Shack to buy the 1.25v NiCad batteries, but since I'm not too adept at electronics (and don't own a sodering gun), I'm nervous about putting it all together.

1. Do I have to soder the contacts together, as they are on the old pack)?

2. Do I have to tape it all together, or can they go in loose on the plastic clip piece.

3. Does it matter that the sodered tips on the other end are touching? Or should I break them off or bend them back?

Sorry to be such an amateur, but thanks for putting together this site and for helping out a devoted, if naive, friend.


#3

Soldering batteries together is not recommended as heat is a battery's enemy. If this was done to your previous pack, it could explain the early death. Spot welding is the only way to fabricate a pack properly. Soldering to a tab that has been welded on is okay as the heat imparted to the battery is minimal.

Also, on a spice, the battery compartment is very tight so adding even a small amount of solder can make the pack too long and you may end up bending or breaking the calculators contacts.

There was a previous thread not long ago:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/forum.cgi?read=49454

Digi-key is a good source as well as TNR Technical (see the "Batteries" section here). The only down side to mail order is the shipping might be more than the battery when buying only one pack.

Another source for pre-welded packs are replacement cordless phone batteries. Find a 2 cell or 3 cell AA pack at your local Mart of choice and simply peel the heat shrink wrap off. They should all have welded tabs internally.

#4

Hello Gerry,

if you do not want to solder the cells, just put them loose in the battery compartment (in the proper orientation of course). One side of the cells is now touching the HP32S's contacts. The battery contacts on the other side must be connected. I had good experience in using a small folded piece of aluminium foil for that. It's thickness also holds the cells in place.

You know that you can use normal AA sized alcaline batteries for that calc? But don't try to load them!

Holger


#5

Although I wrote something about "HP-32S", it was meant to mean HP-32E! The 32S uses button-cells.

Holger

#6

1) You don't have to solder the cells together but you should be able to find a "two pack" of AA cells already soldered together at Radio Shack. They may be in a thin plastic cell phone battery case but that's just an exacto knife away from freedom. Anyway; the HP battery pack stainless steel clip will make the contact between the two batteries without soldering.

2) You don't need to tape it up, it's pretty tight in there, but a bit of the old scotch couldn't hurt.

3) Remove anything flapping and long enough to touch something else. I just grab them with plyers and rip them off. I've never dammaged the battery doing that but you can cut it if you're the careful type.

4) As was said; you can just use regular alkaline AA cells but never never never use the charger with them in there. I use slighty used AAs because the calc wants 2.5 and not 3 volts, but i don't think it's a real big issue because the calc seems to be not easily dammaged by 0.5 extra volts. There was even a post a while back where someone put the batteries in backwards. It didn't work but it didn't kill the calc either.

5) NEVER use the charger without good nicads in place and making good contact. You probably knew that.

6) Holger: we know what you meant.


#7

Thank you all for the advice. I think I'll just buy the pack from Digikey because I'm lazy and risk averse. But are you saying that I can use regular AA alkaline batteries, so long as I don't try to re-charge them? Sounds way to easy!

Thanks again!


#8

Yes, a lot of us use regular alkaline batteries. If one doesn't use the calc a whole lot or permanently store programs (you can't on an "E" model anyway) then it's just simpler to use non-rechargables. If you have programs loaded into a "C" model and don't want to re-enter them each time you turn it on or are a serious collector and purist (or use it seriously and keep it switched on) then you will probably have and use nicads with a charger.

#9

If you have a local Batteries Plus or Batteries Etc store (or something similar) there is no need to mail order a pack. These stores can rebuild your old one or supply you with anything that Digi-Key can.


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