i’ve been rocking a pair of these ones on amazon for about $50 post tax n such since June 4th of this year and they’ve been great for me. little over double the MaH of stock and i get ~8 hours out of them on a full charge consistently using low power mode in gnome. took a few cycles of like 5% to full for the Pocket to properly work with them and get the battery life i expected, which is testament to the BMS board’s design (shout out to MNT!). i made some basic 3D printed spacer bars as seen in my post about turning my Pocket Reform into a cellphone replacement, which i can upload the CAD files to dropbox later today if you want.
with the batteries, spacers, and some JST connectors with the metal inserts (with careful note of polarity!), and thin double sided tape on my 3D printed inserts later, and i was good to go. you can also do without spacers, just make sure the batteries are placed as close to the BMS board’s temp sensors as possible (i haven’t had issues, likely because mine are as close as possible, same distance as original stock batteries give or take a mm), and then put the double sided tape on the top, so they stick to the lid. they barely fit but it’s just big enough, and with a capacity upgrade like that, hard to complain. also if you stick them to the lid, keep in mind not to tuck your wires insanely, and mind how you open it so you don’t tug on things and break it
can’t recommend the upgrade enough, and huge props to MNT for making this so insanely easy.