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Battery life

Posted: Mon Feb 05, 2018 10:12 pm
by keithdalby
I have now had to put my third CR2032 in my DM42. The last one in it was from a reputable brand, from grsbanks. It was not long ago. I understand others have had batteries last months in their units. I don't use it too heavily really, so I was wondering if anyone else has noticed they've had to replace their battery as frequently? Three times since the beta testing began (not including the pound shop battery fiasco), probably a couple of months since the last Panasonic. Use about 5-10 minutes (on and off) each day.

Re: Battery life

Posted: Sat Feb 10, 2018 9:18 am
by Jebem
Is the average current consumption published by SwissMicros?
I'm not saying it is not advertised somewhere but I couldn't find it.
Publishing hardware related specifications officially like Casio and others do would help to understand the calculator expected behavior.

Re: Battery life

Posted: Tue Sep 04, 2018 7:43 pm
by tbruylan
Hi, not sure if still relevant, but I have the same issue. Put in a fresh battery (tried Panasonic and Varta) and it drains in about 3 to 4 weeks. Is this the expected lifetime of a battery, or is something wrong? Calculator usage is also limited to a few minutes per day max.

Re: Battery life

Posted: Wed Sep 05, 2018 2:28 am
by rprosperi
tbruylan wrote:
Tue Sep 04, 2018 7:43 pm
Hi, not sure if still relevant, but I have the same issue. Put in a fresh battery (tried Panasonic and Varta) and it drains in about 3 to 4 weeks. Is this the expected lifetime of a battery, or is something wrong? Calculator usage is also limited to a few minutes per day max.
A few is... how many?

And are those few minutes pressing buttons for manual calculations, or is it a few minutes of continuous program execution?

If only 3-4 minutes per day of manual entry and batteries die in 3-4 weeks, I'd look into it further.

Otoh, if this means 5-10 minutes daily of mostly continuous program execution, I'd say 3-4 weeks isn't bad at all.

More info will help to give better feedback.

Re: Battery life

Posted: Wed Sep 05, 2018 6:10 am
by keithdalby
Michael exchanged my beta calculator for a production model (the PCB part) and the battery drain issue vanished. Maybe connect an ammeter in series with a regulated supply and see what the current does when the calculator is swiched off? Sounds like you've the same issue I had. I am curious what the fault was on my unit.

Switched off:
Screenshot_2018-09-05-05-16-24_1.jpg
Screenshot_2018-09-05-05-16-24_1.jpg (134.24 KiB) Viewed 5677 times
Switched on:
Screenshot_2018-09-05-05-16-32.jpg
Screenshot_2018-09-05-05-16-32.jpg (211.43 KiB) Viewed 5677 times

Re: Battery life

Posted: Wed Sep 05, 2018 7:51 am
by Vitasam
keithdalby wrote:
Wed Sep 05, 2018 6:10 am
Switched off:
Sorry what was a current at OFF stage? 80 uA?

I'm afraid that I do have the same issue with a battery drainage.

Re: Battery life

Posted: Wed Sep 05, 2018 8:26 am
by keithdalby
Vitasam wrote:
Wed Sep 05, 2018 7:51 am
Sorry what was a current at OFF stage? 80 uA?
That's right. 'twas draining far more charge while turned off than on. Michael asked me to send my PCB back to him to investigate and sent me a replacement. The replacement does not have this issue at all. The PCB was replaced at the start of March this year, and the voltage display still shows 2.91V - which I don't think has changed much at all in six months.

Your best bet is to ask Michael.

Re: Battery life

Posted: Wed Sep 05, 2018 8:34 am
by Vitasam
keithdalby wrote:
Wed Sep 05, 2018 8:26 am
Vitasam wrote:
Wed Sep 05, 2018 7:51 am
Sorry what was a current at OFF stage? 80 uA?
That's right. 'twas draining far more charge while turned off than on. Michael asked me to send my PCB back to him to investigate and sent me a replacement. The replacement does not have this issue at all. The PCB was replaced at the start of March this year, and the voltage display still shows 2.91V - which I don't think has changed much at all in six months.

Your best bet is to ask Michael.
Thank you! But first I will do the same measurements

Re: Battery life

Posted: Thu Sep 06, 2018 1:18 am
by MikeD
I had the same issue but this problem was fixed in the latest FW. Did you try installing the latest FW? I was told my Michael that there was excessive current draw from the quad SPI device in the mode it was set to. This was changed in the latest FW. Since then. I have not dropped 0.1V in 2-3 weeks!

Re: Battery life

Posted: Thu Sep 06, 2018 6:34 am
by Vitasam
MikeD wrote:
Thu Sep 06, 2018 1:18 am
I had the same issue but this problem was fixed in the latest FW. Did you try installing the latest FW? I was told my Michael that there was excessive current draw from the quad SPI device in the mode it was set to. This was changed in the latest FW. Since then. I have not dropped 0.1V in 2-3 weeks!
Thank you! That's a good info. I just flashed the latest FW (3.9.1?) but did not have chance to see the battery drainage.