Batteries for 41CV or 33E


I'm looking to add a Spice and a Coconut to my collection. I don't really have any preference as to which model as long as it in excellent - mint condition and works properly. While shopping for these (and BTW, if you have one for sale or trade, let me know), what should I be concerned about regarding batteries? Can I use regular Duracell / Energizer / etc. batteries in them, or do I have to use the rechargable batteries that is supposed to come with the calculator? I don't want to damage the calculator with regular alkaline batteries if I'm supposed to use rechargables. Thanks in advance for your suggestions.


Spices were rechargeable, but the 41's came with a battery pack for 4 x N-sized dry cells as standard. The rechargeable battery was an option.


--- Les



So if I buy a 33C, 33E, or 34C I need to make sure I use it only with the rechargable battery pack, right? If they're selling just the calculator and case and I don't want to mess with a battery pack, the I should pass on it, right?

For the 41CV or 41CX, I can always run some Duracel "N" batterie, right? My 28S uses them and I never mind staying on top of the battery situation.

Thanks for helping out!


I'm no expert on the Spice series, though I did buy a 32E for my girlfriend years ago. But if you get one with a dead battery pack, it shouldn't be too difficult to replace the batteries with new rechargeables.

The 41's, though, have a choice of N cells or the rechargeable pack, though you'd really only want the latter if you're using the card reader more than occasionally.


--- Les



Gulp, pardon me for intruding, but I would like to comment on the remark about the rechargeable battery pack and the card reader usage.

According to HP's own specifications, the Alkaline batteries have 11 times the capacity of a fully charged rechargeable battery pack. If minimizing the cost of batteries is the object, I suppose that one could make the argument that a rechargeable battery pack would be preferable, but if the reliability of the card write/read function is the most important, as it certainly would be to me, then a person should always opt for installing a brand-new set of Alkaline cells before beginning to write or read a long series of cards with the 82104A reader.

Jim Chumbley

Edited: 8 Nov 2005, 4:01 a.m.


The alkalines have higher capacity, but the nicads can deliver more peak power. Their discharge curve is more suited to the card reader power requirements than the alkalines. You will probably get more read cycles off of a set of freshly charged nicads than fresh alkalines.


So how much current does the card reader take, anyway? And how many seconds does it take to run a card through? One? According to my old Radio Shack battery guide book, running an ankaline N cell at 300mA (which I expect is considerably more than the card reader takes) for four minutes every hour, eight hours a day, with 16 hours' rest (enough for over 200 cards in those four minutes if I remember about how fast they go through, and if it really took 300mA),it should still last 70 minutes of the card reader motor actually running, or about 4000 card passes. I expect however that the card reader takes less than that amount of current, and that probably even the most dedicated user doesn't do 4000 card passes in a year, let alone in the self-discharge time of a rechargeable battery. Since you also can't keep feeding them non-stop for four minutes (or even a tenth of that time), there will be more recovery time between them.

I got the tape drive instead. Generally it was a much better solution, but I didn't like the fact that they made it unable to take regular alkaline batteries so I could leave it logging data remotely and automatically for a whole work day. The NiCads were only good for four hours on a charge if they were in new condition, whereas a set of alkalines could have gone a couple of days.


Okay, I've reconsidered this. What if... I just used typical rechargable batteries that I find at Radio Shack, Wal-Mart, etc. in leiu of the original battery pack that was designed for the calculators (including models from the Classics, Topcats, Coconuts, and Spice)? This way I could expand my collection to include some of the older HP families without going nuts of trying to hunt down some hard-to-find battery pack designed to only work in this calcs. I really don't plan to use them for hardcore work but to give them an easy life of just doing the bills and a few logarithms at work (no programs or need for expansions cards). I hear a lot of talk about battery packs for these older units and don't want to put myself in a position where I'm always on the lookout for a special part. I want some degree of convenience and accessibilty when it comes to powering these little machines. Thanks again for the help and direction so I can make good decisions to build my collection.


Hi Steve.
You won't be able to find original batteries for any of the Spice, Woodstock, or Classic HP's. The rechargables currently available (at Radio Shack, etc) work just fine though. The original batteries for my 29c were rated at 1.25v, and of course they are long since dead, but the Radio Shack NiMH's I'm using now (which are rated at 1.2v) work just fine. I would shy away from using alkalines, as their voltage rating is 1.5v, and I've measured them at 1.7v, which may be getting a bit high (allthough I did use them for a short period in my 29c, with no apparent ill effects).
Good luck expanding your collection.
Best regards, Hal


Okay, great! Thanks for the help. I now feel that I can expand my collection of older HPs using the Radio Shack rechargables as long as I keep the voltage at the proper level.


I would not recommend any mass marketed consumer type AA's in a Spice - they're too long and you will most likely break the battery tabs off using them.

You want to purchase any ni-cd or ni-mh cells with flat ends as these are a bit shorter and provide more contact area, they have no pointed tip on the + end as you find with consumer batteries. Any good battery store or Digikey can supply. You also need the welded strap on one end for good contact, the small metal piece in the original Spice pack isn't sufficent.

See Katie's article for numbers: Replacement batteries

Edited: 6 Nov 2005, 8:14 a.m.


Thanks for that great piece of advice. I'm just wanting to do this right. I don't plan to use an LED model professionally. The most action they'll see will be just doing the bills.

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