Power consumption when the PicoCalc is powered off

PicoCalc
1

Hi all,

Yesterday i powered the Pc of at 22:52, the battery was at that moment 97%

Today at 19:05 i booted up the device and the battery was at that moment 81%.

is it normal that the Pc consumes so much energy?

I use 2x protected batteries each 3500mAh

and it uses the default firmware ( got the device just 2 days ago)

what are your experiences with the power consumption?

2

Mine is much better than that. Maybe your batteries are self-discharging somewhat more than most ?.

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3

18650 cells drop off fairly quickly from the 4.2v down to 3.7v and level off for most of their cycle and then drop off down again, think of the 4.2v more like a surface charge, 3.7 is their real working voltage. a bit like NiMH cells, they will charge to 1.5v but most of that is surface charge, their real operating voltage is about 1.2v.
Also the protection circuits will draw power as well as the Picocalcs standby current for the Power switch monitoring (is so negligable though).
hope that helps a little :smiley:

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4

thanks for the answers.

i think that is the most logical thing, that these batteries are a bit more self discharging.

Mine are from the brand KeepPower

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5

I use batteries that I’ve recycled from some old laptops (there are certain laptop models from a few years back whose batteries usually contain 4 or 6 x 18650 cells).
Since the price of a pair of brand-new batteries is quite high around here, I rely on the ones I’ve salvaged.

Well, even though these aren’t new batteries, I discovered something today: yesterday morning I forgot my PicoCalc turned on inside my backpack… and apparently, it doesn’t have “auto power off.” But after 18 continuous hours of running (and it didn’t even start at 100% charge, probably around 90% or so), it was still on! With about 5% charge remaining.

So I guess the power consumption is actually very low. And with the convenience of being able to swap in another two fully charged cells in a second—it works perfectly for me!

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6

My picocalc draws an average of 25 microamps when off.

It’s almost certain that you’re seeing variations while the battery gauge calibrates itself, not any real change in the battery level. These will subside after you use it more.

It’s only if you see consistent, repeated excessive battery drain over multiple charge cycles that you should go looking for problems.

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7

that sounds really good @ArielPalazzesi

@pelrun thanks for the explenation,i didn’t think about that.

for now i just going to use it as it is and see how it goes :slight_smile:

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