I have two of those: https://kopplen.com/collections/phone-charging/products/kopplen-palm-sized-10000-mah-dual-usb-power-bank-blackpbk-pd07blk
(Can be found at BestBuy or Walmart if you're in America)
With this adapter:https://www.amazon.com/Mobile-Charger-ACK-E12-Coupler-Battery/dp/B073Z75LSF/ref=sr_1_3?crid=1STNDKOLYCOTK&dib=eyJ2IjoiMSJ9.Dso_Iid1RmbDLxqiFgNjcOINeu332OdyaMg4wybk95CQZHVH4Hla9P74cMi5qZqXYWGcrhOfNB9tPymjFvc2Ha79oFBPl-iMV6JpQT84G0psb9hznvh_GSm1_GnTscPddVctlWQJ77pDyAl9QNsehjKkPhCbr7DYyN5ODjvSLXaYpAEzVncV9THRzr3YrLoeTHqgR9caYBvAU4rdMj7NN0-Wxitsyag1-GmSjNpXLM8.j4mgS4vZw8rUe3-8HU_6hyqPLAoSzQUmOjkdaf8ciJE&dib_tag=se&keywords=canon+eos+m+dummy+battery&qid=1714103575&sprefix=canonn+eos+m+dummy+battery%2Caps%2C253&sr=8-3
Will last about 7 hours on a full charge (I turn off the camera when i'm not recording)
Whatever you get, it needs to output at least 2 Amps @ 7.2v, otherwise the cam won't work well, if at all (Turns off randomly).
I have heard that when you use a usb powerbank with a usb voltage converter, the voltage is not as steady as with a powerbank with a straight 7.2-8v output, so it could damage the camera in the long run,because there is no regulator inside the camera (It expects a battery). I haven't opened the camera to check that claim, so you may want to do same research on that topic to make sure...
EDIT: see @walter's post below
(Can be found at BestBuy or Walmart if you're in America)
With this adapter:https://www.amazon.com/Mobile-Charger-ACK-E12-Coupler-Battery/dp/B073Z75LSF/ref=sr_1_3?crid=1STNDKOLYCOTK&dib=eyJ2IjoiMSJ9.Dso_Iid1RmbDLxqiFgNjcOINeu332OdyaMg4wybk95CQZHVH4Hla9P74cMi5qZqXYWGcrhOfNB9tPymjFvc2Ha79oFBPl-iMV6JpQT84G0psb9hznvh_GSm1_GnTscPddVctlWQJ77pDyAl9QNsehjKkPhCbr7DYyN5ODjvSLXaYpAEzVncV9THRzr3YrLoeTHqgR9caYBvAU4rdMj7NN0-Wxitsyag1-GmSjNpXLM8.j4mgS4vZw8rUe3-8HU_6hyqPLAoSzQUmOjkdaf8ciJE&dib_tag=se&keywords=canon+eos+m+dummy+battery&qid=1714103575&sprefix=canonn+eos+m+dummy+battery%2Caps%2C253&sr=8-3
Will last about 7 hours on a full charge (I turn off the camera when i'm not recording)
Whatever you get, it needs to output at least 2 Amps @ 7.2v, otherwise the cam won't work well, if at all (Turns off randomly).
I have heard that when you use a usb powerbank with a usb voltage converter, the voltage is not as steady as with a powerbank with a straight 7.2-8v output, so it could damage the camera in the long run,
EDIT: see @walter's post below