XX battery is not something dangerous or NSFW. It’s a new Sanyo Eneloop battery that is both stronger and cooler (the design). Sanyo XX Battery is using the similar eneloop technology, high-capacity Ni-MH battery, and the battery itself is capable of providing 25% more power for extreme usage.
Sanyo XX battery is an AA size battery which has been pre-charged on the package, with about 25% energy lost on each year if it’s remaining on the package unused. As for the recharge-ability, Sanyo allow users to recharge this battery for up to 500 cycle before you can throw it away.
More great stuff on this Sanyo XX Battery is that you can still use them on low temperature zone. It can still work well even the temperature drop down to -4 degrees Fahrenheit, or equal to -20 degrees Celcius.
Sanyo is going to ship these batteries in a pack of four XX AA batteries for $24.99 in August 2011.