I have m5paper and m5 core ink. But I need long battery backup. Even with m5.shutdown every 10 min and waking up for 30 sec to fetch remote data m5paper lasts for less than 2 days.

So I was thinking of powering these with something like 27000mAh battery pack used for mobile phones. They are supposed to be operating at 20W. I wanted to know if it safe to power M5paper and m5 core ink with these battery packs?

I am thinking of this one: https://www.amazon.in/Ambrane-Multi-Layer-Protection-Li-Polymer-Stylo/dp/B098QV28F7/

Sorry I don’t understand much on the electronics side. Please guide.

Thanks
Pritam