HP 34C calculator


I have an old calculator that appears to be in good condition. The calculator would be very useful in an elementary school teaching volunteer activity of mine. It looks like it needs a new battery. Can you tell me where I might buy one?


The best bet may be to have the original battery pack rebuilt.

I'm not sure, but I believe these calculators can be destroyed if you use the recharger without batteries (or with bad battery pack connections).

Don't try it until you are sure it's not going to fry the moment you run it on.


Thanks for the advice from down under. I don't know a place that rebuilds HP battery packs. The charger itself measures 10 V AC at the terminals. Connect the charger with the switch off and the battery terminals measure 14 V DC. Turn the switch on, and the voltage drops to 7 V DC.

In addition to the bad battery, I think the on-off switch is shot.

I might as well give up. It seems a shame. I've already thrown away two PC's and am about to jettison two more. My HP 15C still works fine and I treasure it. But I don't want to subject it to the rough and tumble of 13 year old students.

Perhaps I can buy a second hand reverse Polish calculator with storage registers and functions that still is in good condition.

Thanks again for responding to my woes.



And keep in mind that that 14VDC hits your calculator's C-MOS continuous memory regardless whether the power switch is in the ON position or not.



Or, umm, *I* have a trash bin and if you'll send it to me, I'll get rid of it FOR you... yeh, that's the ticket...

Seriously, if the calc is dead, parts of it may help others here-- offer it as is. If it works, but has flaws, such as a bad power switch, a few of us may want to try to repair it for ourselves. Sell it. If you only need batteries, heck, that's not an insurmountable obstacle... and you may want to even do it yourself.

A 34c is a good calc for students especially-- though it has no I/O or cards, it IS programmable and RPN (two addictions that ought to be fostered).

Just don't feel like an HP calc is too old or a hopeless throwaway-- if there's any thing we know from experience, it is that the newest models ain't perfect, either....

Recycle! :-)


You never said if you tried it with plain old AA batteries. All you need to do is put a small piece of aluminum foil at the end opposite the contacts, pay attention to the polarity and give it a go. Let us know if it works. Randy

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