The Museum of HP Calculators

HP Forum Archive 13

[ Return to Index | Top of Index ]

Long term storage of calcs.
Message #1 Posted by Graham Wilson on 10 Nov 2003, 9:05 p.m.

Hi all

Does anyone have any tips about the long term storage of HP calculators? I have a couple of spare machines that I am keeping as backups.

Is it better to remove the batteries (assuming programs are backed up onto paper or PC)?

Is it better to store unused uncharged rechargeable battery packs (such as NiMH or NiCd) in a fridge to increase their life?

Thanks
GW

      
Re: Long term storage of calcs.
Message #2 Posted by David Ramsey on 10 Nov 2003, 9:13 p.m.,
in response to message #1 by Graham Wilson

Quote:
Is it better to remove the batteries (assuming programs are backed up onto paper or PC)?

Is it better to store unused uncharged rechargeable battery packs (such as NiMH or NiCd) in a fridge to increase their life?


Yes and yes.

            
Re: Long term storage of calcs.
Message #3 Posted by unspellable on 10 Nov 2003, 9:37 p.m.,
in response to message #2 by David Ramsey

Speaking as a reliability engineer, I would say you should power up the calculator for a few minutes once every other month or so to keep the dielectric formed in any electrolytic capacitors the calculator may have. Between power ups, remove the batteries.

      
Re: Long term storage of calcs.
Message #4 Posted by Paul Marin on 13 Nov 2003, 6:45 a.m.,
in response to message #1 by Graham Wilson

Just a question, while you're on the topic of re-chargables. I have n old 33E, which has a battery which will not charge. What can I buy to replace it? Any solutions?

Any ideas grateful

Paul

            
Re: Long term storage of calcs.
Message #5 Posted by David Smith on 13 Nov 2003, 1:34 p.m.,
in response to message #4 by Paul Marin

Take your old pack down to the local Batteries Plus, Batteries, Etc or any similar battery store. For a rather reasonable fee, they will take it apart and rebuild it with new cells. I use 1800 maH NiMH cells in all my calculators. They are compatible with the charger and will run the machine for three times as long as the originals (as long as you charge them for three times as long).


[ Return to Index | Top of Index ]

Go back to the main exhibit hall