Well, the calculator is sitting on my desk at home and I'm not yet making a lot of use of it. Usage basically means turning on the calculator daily to check the voltage (diagnostics menu) and turning it back off. I could literally see the voltage dropping every day. My battery just ran out a few days ago. It measures 2.01V (after removing it from the calculator), so it's empty.rprosperi wrote: ↑Wed Sep 05, 2018 2:28 amA few is... how many?tbruylan wrote: ↑Tue Sep 04, 2018 7:43 pmHi, 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.
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.
Maybe important to specify: My device was still running DMCP 3.7 (I only noticed when the battery was already close to empty). Thus, I upgraded to DMCP 3.9a a few days before the battery finally ran out. Tomorrow, I will insert a brand new battery. But, I'm going to measure the calculator's current draw first (while at work in our lab with the proper equipment, as shown by @keithdalby). I hope the firmware upgrade to DMCP 3.9a fixed the issue
I will report about my findings
PS: Looking at the PCB, I see that R12 (one of the resistors next to the USB header) is not populated. Is this expected? If a resistor should be there, what value?