Alkaline batteries in HP-21


I know that the HP-21 was designed to have only a 2.5 V Ni-Cd battery pack for power. How badly could the calculator be damaged if someone replaced the 2 Ni-Cd cells with a pair of 1.5 V AA Alkaline batteries?


I have used alkalines in my woodstock (and spice) series units with no ill effects. At the suggestion of someone here, i use used batteries that test nearer to the 1.25v of a fully charged ni-cad than the 1.5v of a new alkaline. I don't know if that is necessary but it can't hurt.


I have used alakline batteries with the HP-21, H_25, and HP-29C with no problems.


Same here...alkalines in my 29c work fine


I have used alkalines in my Woodstocks during 6 years and disposable Lithium AA batteries since the 3 last years without any problems.

Typical use: 1 different calc every day during the whole working day.


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