Getting a battery to work to power an M5 Tough?

[clarksn]

Has anyone had any luck getting a battery working with an M5 Tough?

My intention had been to switch the trailing USB power lead with a waterproof USBC and normally power the unit by a rechargeable battery squeezed inside, so I sourced a small battery and connected it to the tiny internal battery connector and it powered up the device but everything went very hot, but cooled down after I also connected the USB (still at this stage the original USB lead).

I grabbed some sample code to look at power and battery status and play with deep sleep and touch screen restart (all of which worked when the unit was connected by USB) but the battery part of the results were strange with the battery showing only 7mA charge and no voltage. I swapped with another battery and this looked sensible initially with about 85mA charge and a battery voltage over 3v, but I then found that removing the USB the device simply turns off (of course normally its physical power button isn't accessible). Having plugged the USB in again I found the voltage on the battery that was apparently charging reduced rapidly to under 3v and then did a big drop to 0.

I then switched to a third battery and the device went very hot in a matter of seconds and this appears to have fried the board as it now won't talk to my laptop over USB.

An ideas?

thanks

Steve

[felmue]

Hello @clarksn

hmm, this sounds a lot like a polarity issue with the battery cables. Unfortunately there is no standard for this particular battery connector about which pin to be plus and minus. I've seen both variants in the wild.

My M5Tough, powered via internal battery connector, takes about 68 mA @ 4 V when running UIFlow2.

Thanks
Felix

[robski]

see my test on M5Tough with battery