DM42 works with USB but not battery

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jthole
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Re: DM42 works with USB but not battery

Post by jthole »

EM41 wrote:
Wed Nov 04, 2020 9:46 am
I was always a fan of duracell but I have to change that opinion.
Had a few leaks recently, one in the tv remote and one in a wireless keyboard.
These were the devices that didn't have the batteries replaced with eneloops yet.
Checking some batteries it shows duracell made in Belgium and duracell made in China.
The ones from Belgium never leak, the ones from China always leak but the Belgium ones disappeared from the stores.
The smoke and co2 detectors receive Varta from now on and the rest eneloops.
I was already avoiding China stuff but didn't realise duracell is from China nowadays.
For those who can read Dutch: http://www.cr2032-knoopcel.nl/

I always bought Duracell as well, but this test also suggests that they're not the best anymore. I am actually surprised that GP is the winner.
DM42 s/n 06181 DM41X s/n \(\beta\)0005 (sold)
grsbanks
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Re: DM42 works with USB but not battery

Post by grsbanks »

So am I, but glad as I have about 80 of them in storage waiting for me to use them!

I also bulk bought a load of GP 'N' batteries to use in my HP-41C, CX and CL.
There are only 10 kinds of people in the world: those who understand binary and those who do not.
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akaTB
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Re: DM42 works with USB but not battery

Post by akaTB »

grsbanks wrote:
Sun Nov 29, 2020 6:05 am
I also bulk bought a load of GP 'N' batteries to use in my HP-41C, CX and CL.
No CV?
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grsbanks
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Re: DM42 works with USB but not battery

Post by grsbanks »

akaTB wrote:
Sun Nov 29, 2020 12:14 pm
No CV?
The CL was a CV before it became a CL :)
There are only 10 kinds of people in the world: those who understand binary and those who do not.
EM41
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Re: DM42 works with USB but not battery

Post by EM41 »

jthole wrote:
Sat Nov 28, 2020 10:18 pm
For those who can read Dutch: http://www.cr2032-knoopcel.nl/

I always bought Duracell as well, but this test also suggests that they're not the best anymore. I am actually surprised that GP is the winner.
What is not tested here is internal resistance, for the DM's the cheap ones (like the tested kinetics) don't work al all although they power a led easily. The first test is without limiting resistor so there is no objective comparison possible.

The second test with a // resistor over the cell for drawing a high constant current is also not a good measure for testing a battery.
I would like to see a how long each one lasts with 0.5 mA, 1 mA and 5mA intermittend loads (for example on for one sec and 30 sec off).
The more expensive batteries recover better than the cheap ones

A led is not a good testing device because the V/I curve is not linear and light is not a measure, residual energy could be much higher on the ones that fail early on the led test. You need a discharge curve, not a led test.

I think the duracell will perform much better than suggested in this test but indeed the GP looks really good.
HP41C (2x), HP41CV, HP41CX, DM41X β, DM41X, DM42, HP11C, HP48G, HP97
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