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Stand by power WP 34s & HP 35s
08-28-2014, 10:38 AM
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Stand by power WP 34s & HP 35s
Hello.
I own a 35s and I use it rarely, but every time I need it, the batteries are always exhausted (so I use it even less...). Later I modified a 30b in WP 34s and I had the impression that the batteries lasted much longer.
HP declare the same duration for the two calculators (9 months @ 1h/day) so I decided to make some measurements.

Here are the results, measured at 3.00V, 28C:

WP 34s standby: 4.15uA
WP 34s on: 170uA

HP 35s standby: 6.96uA
HP 35s on: 18.3uA

The on power grow slightly with more numbers on the display, the measurements have been taken with all cleared.

If the calculators were able to use the energy of the batteries to 2V, they should last years (a single CR2032 is rated >900 hours @200uA 20C); by my experience, this is clearly not the case. It should be interesting to understand why.
Nevertheless, for low usage rates, the WP 34s wins.

Best regards,
(Mr.) Andrea Baldoni
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Messages In This Thread
Stand by power WP 34s & HP 35s - abaldoni - 08-28-2014 10:38 AM
RE: Stand by power WP 34s & HP 35s - pito - 09-09-2014, 07:10 PM
RE: Stand by power WP 34s & HP 35s - pito - 09-09-2014, 07:30 PM
RE: Stand by power WP 34s & HP 35s - d b - 09-12-2014, 11:19 PM



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