Logitech m330 with a single AA Ni-MH battery. Have been using the same battery for the last 4 months, wondering when will it die.

I also have a smart charger for the batteries, so I can just keep them in there without the risk of damaging the batteries. The moment the battery dies, I’ll just take another one and swap it quicker than it would take me to find a usb-c charger.