The sound-box uses two AAA batteries. We recommend using rechargeable batteries to help protect our environment. Two AAA alkaline batteries can last for up to 120 hours in the Lulla doll.
The time duration depends heavily on the quality of the batteries and the difference can be up to 85%! Better quality batteries cost more but then again they are more reliable and last for longer. Rechargeable batteries do not last as long as they are 1.2V (regulars are 1.5V). But you can use them over and over again making them the best long term investment. Also keep in mind that batteries are sensitive, they need to be stored properly and can get damaged with age and rechargeable batteries can loose their capacity with repeated use.
Here are a few brands of alkalines that have gotten great customer ratings for long lasting performance, in parentheses we included their top brand types :
Duracell (Quantum, Copper Top, Ultra Power),
Panasonic (Evolta, Pro Power),
Energizer (Eco Advanced is their longest lasting alkaline)
In every test we found of rechargeable batteries Panasonic Eneloop stands out as a top performer. There are a lot of chargers on the market and, as with batteries, quality varies a lot. The best inexpensive charger we could find was also the Panasonic Eneloop charger- you can even buy it in a bundle at Amazon.