Building the mouse Logitech won't make

My favorite mouse is the Logitech Anywhere MX. It's highly comfortable despite being pretty small. The back/forward buttons on the side are indispensable for web browsing, file management, and switching weapons in first-person shooters. It takes two AA batteries which last for months and take seconds to swap out. The dongle is small and has good range. The scroll wheel switches between clicky and free-scrolling.

It's pretty much the perfect mouse, IMO, to the point that I built up a back stock by hoarding new and open box on eBay. But there are two main problems:

1) The the microswitches go bad after a couple years. It's possible to replace them, but it's tedious and you run a very real risk of damaging the PCB (as I have already done).

2) The dongle is USB Type-A only. Logitech actively refused to make a USB-C unifying receiver. I assume they wanted to shift to bluetooth but they still made unifying receiver devices for years and years after bluetooth was everywhere, so I dunno.

As far as newer iterations, the Anywhere MX 2S is somewhat tolerable, but it has a built-in battery which must be charged every couple of months, which is annoying. All of the newer Anywhere MX mice are even worse because they changed the basic functionality/features of the mouse with each revision. Oh, yes and they cost $90 (!) retail now.

So basically one of my side-projects, one of these days, is going to be to try building an open source Anywhere MX clone. Should be a fun yet challenging endeavour. I know there are a bunch of online communities making their own keyboards from scratch and at great expense, is there such a thing for mice?

Built in rechargeable batteries are a plus, not a minus.

I consider them a minus because the proprietary batteries will likely fail before the rest of the mouse does. Using standard batteries means you’re not at the mercy of Logitech’s warranty when that happens. I wish more devices use standard batteries, but planned obsolescence is a hell of a drug.

FWIW, some of logitech's mice use "standard" rechargeable batteries - they look like an AA battery and are roughly as easy to replace (after 5-10 years of use).

AA-size Li-ion is called "14500" for anyone needing to source these. I'd love a mouse (or various other gadgets for that matter) that uses one behind a tool-free battery door.

I just went and took mine apart, it's a Logitech Performance MX, and it uses a NiMi battery: 1.2v, 180mA, 1900mAh.

The battery door pops on and off with a fingernail.

They really do look like dead-ringers for AA batteries. I bet you could run the mouse off of a regular AA as long as you didn't try to plug it in!