Battery powered issue

simian311
Posts: 2
Joined: Mon Aug 22, 2022 9:57 pm

Battery powered issue

Postby simian311 » Fri May 05, 2023 4:28 am

I am running my TTGO ESP32 using a 16340 3.7v 800mah battery. When measuring the battery with the device awake and screen on the voltage is for example 3.0v and when I put the device into deep sleep the battery rises to 3.2v. I am using MCP130-315HI/TO supervisor to monitor the battery voltage and the issue is that the voltage drops below the supervisor threshold and it pulls the reset low turning off the device but then when the device is off the battery voltage rises over the supervisor cut off and powers the device back on causing the battery voltage to drop again and so on. Any idea how to get around this issue?

MicroController
Posts: 1554
Joined: Mon Oct 17, 2022 7:38 pm
Location: Europe, Germany

Re: Battery powered issue

Postby MicroController » Fri May 05, 2023 11:15 am

A battery with lower ISR/higher current capability might mitigiate the issue because the drop/rise of the voltage would be lower, ideally staying below the hystheresis of the battery monitoring chip, so that once the turn-off threshold is reached the voltage won't rise above the turn-on threshold by itself again.

A beefy capacitor in parallel with the battery will also reduce the battery's apparent impedance, reducing the amplitude of voltage drops caused by spikes in current consumption.

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