The batteries (4xAAA) that come with this charger are only 750mAh. You can't even find rechargeable batteries with that low capacity.Since this charger works off the Wii's USB (or even on a PC) port, in order for this charger to work (recharge batteries in remote), your Wii must be powered ON all the time which translates in to "shortening" your Wii's life span.