Decided I was going to open mine up because I can't comfortably use a device I haven't taken apart before (seriously - I'm kinda screwed up). I honestly didn't find it that hard. You need to be fragile, and there are exposed wires, but it's not impossibly hard that's for sure.
Remove the top by taking a blade and using it as a shim to pop the bottom section off. Push towards the dial, on the side opposite to the micro-USB port.
Careful, these wires look fragile
So there is only one battery in this guy, and it's a standard 18650 li-ion cell. Comes right out and you can get these anywhere. Put the bottom back on by putting the MicroUSB connector back in to the hole (like a hinge) and then pushing on the other side
Chalk up another plus for this guy;
bool $user_replaceable_battery = True
Remove the top by taking a blade and using it as a shim to pop the bottom section off. Push towards the dial, on the side opposite to the micro-USB port.
Careful, these wires look fragile
So there is only one battery in this guy, and it's a standard 18650 li-ion cell. Comes right out and you can get these anywhere. Put the bottom back on by putting the MicroUSB connector back in to the hole (like a hinge) and then pushing on the other side
Chalk up another plus for this guy;
bool $user_replaceable_battery = True