Batteries for HP-42S

[rprosperi]

(04-09-2017 10:42 PM)Thomas Okken Wrote:  I'm looking for recommendations re: brands and suppliers, to avoid this kind of surprise in the future. Can anyone point me in the right direction?

Be sure you get Silver Oxide and not Alkaline batteries, they are often marketed with the same (externally compatible) part numbers, but the SO last much longer (but they do cost more).

After a lot of searching 2 weeks ago, these were the best value:
http://www.ebay.com/itm/252012590010.

I've had very good results with Energizer batteries, and for barely over a dollar each, a good value. (Vendor has listings in various quantities).

As other recent posts have also noted, clean the contacts when changing batteries, DeOxit (Red) works very well for all calculator contacts.

These are rated for shelf-life until 2020, so getting a few extras now has no notable bad effects.

There are many different model numbers for this size, even from the same manufacturer, though I've gathered that models ending in "W" denotes a Watch battery, while those ending in SW denote Slow-drain Watch battery. This model does not use the W/SW notation, but as these are called multi-drain, this presumably means Slow and Normal.