Trial of Lithium Polymer battery with the MAX32630FTHR feather.
The MAX32630 has a PMIC onboard, for 100mAh charge rate, with a JST PH 2.0 connector to connect a battery, like the feathers from Adafruit.
I didn't have any of such connectors at home, so I asked Dan and Randall to get me them, and crimps and housings showed up at my door a few days later.
I did have some lithium polymer batteries, from GPS's I dismantled. These batteries are 10-12 years old.
I wouldn't expect much from the battery life.
So essentially, I charged this thing for 5 hours.
That should be a charge of around 500mAh.
It works, but it's a bit annoying since you have to hold the switch next to the battery connector and then it will launch.
This might be a bit of a problem for some users. The button is located at a position which makes it somewhat difficult to reach, especially if you are adding an enclosure.
Other than that it works rather well.
I cannot test overall battery drain, since my multimeter's fuse blew, and I haven't gotten a replacement yet.
I'll be testing with lithium Ion batteries, specifically 18650 batteries.
Don't mind my connections, I soldered them on because I have no crimpers.