Looking at the MNT Pocket Reform components in the The MNT Pocket Reform Operator Handbook, I found a single replacement option listed in the compatible battery cells, namely the EREMIT 606090, 3.7V, 4000mAh, LiPo. According the handbook, these battery cells can be acquired directly from a single vendor:
Reading the specifications of both battery cells, both has the number 606090, and the same specifications of volts and amperes. However, they differ in the size, 6×60×90mm and 12×60×90mm, respectively. So, I guess one fits on the Pocket Reform, and the other doesn’t. Also, one is available and the other isn’t.
Since I don’t know much about battery models, I wonder about the risk of having no replacements after 5 years. I imagine that I will still find batteries in the AAA format, but I don’t know if there will be batteries in these less common formats. Please let me know about this risk.
Hi, I’m working on this exact issue at the moment. You can theoretically use any protected LiPo 3.7V cell that fits in the case (and ideally has 2 pin JST-PH connector). The holders are designed for 606090 format, but it can also be thicker, like 706090 which I found on Amazon with 5000mAh. The only issue is that often the JST-PH connector has the polarity flipped vs our cells, but you can swap the crimped ends of the connector relatively easily with a sharp plastic tool (and be extremely careful not to touch anything with the red wire’s end).
Apart from these DIY solutions, I’ve started talks with a battery manufacturer so that we can sell replacement batteries ourselves next year.
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.
Thank @minute for your answer! Thank @Nebula-System for reporting your experience! It seems that batteries will not be an issue, because it is question of time that they will be sold by MNT. And anyway, it would not be so difficult to find and install an alternative replacement.