Rechargable batteries offset the shorter life of AAA and even AAAs last a long time in blinkies. I prefer NiMh batteries. Even though they are pricey, they last through hundreds or recharges and retain good life. Renewal rechargable alkalines are OK; don't cost much more than regular alkalines but don't have the same charge life as NiMh. I also have a neat Supercharger that I got for about $8 that recharges regular alkalines. It works great. It is especially useful for the 4 D Duracell Ultras I use in my headlight. The NiMh Ds I have seen were only 2200 mah which is pitiful. A regular Duracell AA is 2750 mah and the Ds are 15000. I probably get about 100 hours (total over multiple recharges) out of a set of 4 Ds.