HP 21


I still have the HP 21 that I used through engineering school, it does not have a battery pack or charger. I sure would like to get it back in operation. Can you direct me to anyone that can help me get it back working?




fixthatcalc.com could probably do it, and there have been some rebuilt battery packs listed on eBay recently, though others would know better than I if they are for 20-series calculators.


The fabricated packs on eBay are for the Classics (35/45/55/65/67/70/80), they will not work for a 20 series Woodstock.

Woodstocks require a specific battery, a two piece plastic shell which got sealed together, encapsulating two AA rechargeable cells with a spring in one end. Very special and quite hard to find as they usually got thrown out years ago when they showed signs of leakage. HP ceased battery sales in 1995 (or thereabouts) so replacements are non-exsistent other than eBay and those usually come with a calculator...

Personally, I have more calculators and chargers than batteries for my 21/22/25/25C/29C and yes, I'm still looking for a 27 :(

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