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Running 128x64 OLED on Coin Cell
Moderators: adafruit_support_bill, adafruit

Running 128x64 OLED on Coin Cell

by TheGrovesy on Thu Dec 06, 2012 11:36 am

Hi there,

I believe I should be able to run the 128x64 oled adafruit display on a 3.3v coin cell battery (rated at 1000mAh) is this correct?

If so am I also correct in my understanding that with the display rated at (on average) 20mA, if I did have it on all the time (which I wont BTW) it would last 50 hours (1000/20)!!! This seems a long time for such as small battery, so am i misunderstanding how the ratings work? I do realised that in reality I will be powering other component, micro controller etc, but in theory if it was just the display is my calculation correct?

Many thanks,
Chris
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Re: Running 128x64 OLED on Coin Cell

by adafruit_support_bill on Thu Dec 06, 2012 12:37 pm

It should run. But how long is the question. Most coin cells have a relatively high internal resistance and their mAh rating drops dramatically with a higher current draw. Duracell rates their CR2302 cells for 240mAh, but that is at 0.19mA. As the current increases, the voltage drop across the internal resistance increases and less voltage is delivered to the load. I'd suggest testing one at 20mA and see how long it puts out a reasonable voltage.
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