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WP34S: Reset when printing statistical registers?
07-04-2014, 11:12 AM (This post was last modified: 07-04-2014 11:22 AM by pito.)
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RE: WP34S: Reset when printing statistical registers?
(07-04-2014 07:49 AM)walter b Wrote:  Thank you for the calculations. We shouldn't forget that the WP 34S switches off for voltages <2.1V.

I've taken a fresh CR2032 (Vinnic?) from my stock:

1. Voltage without a load (actually 10Mohm, I = ~332nA) = 3.32V

2. Voltage with 200ohm load = 2.89V

3. Internal resistance of the battery is 

Rint = dV@Rint/dI@Rint = (3.32V - 2.89V)/(2.89V/200ohm - 332nA) = 29.75 ohm

So my above estimation was rather optimistic. Both batteries in parallel will have ~15ohm Rint when fresh. The load of ~15mA will create a ~0.22V drop with two fresh batteries in parallel.

When measuring with BATT not loaded with the "nominal load", you will measure ~3.3V, what is of course a "Hausnummer" Smile

When 50-60% capacity consumed, a 10mA load (a calculation for example) will drop BATT below 2V (but the BATT will show you 3V).
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RE: WP34S: Reset when printing statistical registers? - pito - 07-04-2014 11:12 AM

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