From HP 41 to WP 34 S

[rprosperi]

(02-09-2015 10:54 AM)garfy Wrote:  but i liked red leds.. like a ti watch i had.
if battery could be available, i could buy old hp 29c or hp67.. but with the battery problems..

i keep a like new hp 41 battery, made by a french store. i verified it works well, so i search an HP 41 cx or CL( modified hp41)
i dont find a good one .

Batteries for the 67 are available cheaply on auction sites (they also fit 35, 45,65,70,80,75C/D, etc.), and the 29C battery case can be easily opened and you can use either 2 x AA Alkaline batteries or use 2 x AA-size rechargeable NiCd cells, also cheaply available from many online sites (e.g. here - note you should get the flat-top style as shown).

For the 41C you can of course use N-sized disposable batteries, but rechargeable 41C batteries are also available on auction sites, one seller even offers a lifetime guarantee.