The big benefit of rechargeable batteries, aside from possibly being more ecological, is they’re supposed to save you money in the long run. However, blogger Len Penzo argues that for some devices, you’ll spend more money if you go the rechargeable route.
For example, it makes much more sense to use traditional alkaline batteries for low-draw devices like your wall clocks, radios, smoke detectors, programmable thermostats, and remote controls because they lose power at a much slower rate than rechargeable batteries.
And because traditional alkaline batteries can hold a charge for years when not in use, they are also the better choice for items that may sit unused for long period of time, like your alarm clock back-up battery and emergency flashlights.
For high-drain devices—think video game controllers and personal massagers—he says rechargeables are the way to go.
“Why Rechargeable Batteries Are Rarely Cost Effective” [Len Penzo]