Calculator collection : How to power calcs without constantly opening?

[John Keith]

For the Voyagers which use 3 x SR44 cells it is safe to leave batteries in them for extended periods because silver oxide cells rarely leak. Just make sure they really are silver oxide type: the LR44 cells that also fit the Voyagers are alkaline cells which are not as leak-proof.

There are tales of batteries in voyagers lasting for decades, but I replace them every 3 years or so just to be safe.

For the Classics which use Ni-Cd cells the only safe option is to leave the battery packs outside of the calculator.