HP 34c battery voltage voltage


I have a new hp34c that came with 1.5 volt off-the-shelf alkalines installed. I was concerned about any physical stress that the slightly too-long batteries may have been causing on the PCB, so I bought a pair of rechargable tip-less NiCds. The battery clips in the calculator have been flattened out because of the alkalines, and I did not want to bend them back out, so I padded the extra space with some tin foil and the new NiCds are a perfect fit.

But I am now concerned that they are 1.2 volts instead of 1.5 volts. Will this slightly lower voltage be a problem for the calculator? hpmuseum's battery spec page recommends a pair of radio shack NiCds which are also 1.2 volts.


NiCd always are rated 1.2V. This was equally true for the original batteries in the calculator. So 2.4V is certainly ok.


Whenever you see the word NiCad think instead Nimh. The are more modern without the memory effect of Nicad. I have had such good results with the low self discharge Sanyo Eneloop cells I can recommend them for any service. They hold enough charge tto last over a year. Sam


Great, thanks.

Oddly enough, I let it charge for about 6 or 7 hours and the low battery indicator still comes on when I power up the calculator.



Chances are that the connection for the charger is faulty. I repaired (and replaced) many of the flex circuit that connects both the batteries and the charger input to the power board. If you have the means to, please check if the charger is actually feeding the power board.


Luiz (Brazil)


I've used 2 AA alkaline batteries in my 34c for 5+ years with no problem. I open the battery compartment every year to do an inspection looking for battery leakage.



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