If you're going to sit and swap out the batteries that have run out with other non-rechargeable batteries anyway then you might as well get a pack with 4 rechargeables and a charger, then alternate them in sets of 2....
Wireless keyboards take ages to go through their batteries.
Wireless mice have come in cradle-charging, hotswap battery packs (with charging cradles) and aux cable varieties for over a decade now - gaming mice with this utility are more recent, however.
Lol I remain happy with my logitech wireless mouse. Decent dpi, responsive and the batteries last ages. Have had mine for 7 months now and haven't needed a single battery change and it's been working hard during weekends when I decide to play an RTS or FPS game when I'm taking a break from my studies
Oh yeah, it might be worth pointing out that the A4Tech and MX610 mice I listed in the uberlong post earlier were used practically all day every day, as I've been a stay-at-home-do-stuffer for the past decade or so <.<
So if I can get up to 2 months on one charge on the MX610, imagine how long it could last someone that only uses their computer for a few hours a day.