FDK (formerly Sanyo) Twicell (formerly Sanyo Eneloop) 4.8V, 2000mAh, AA 4 Cell Flat Pack.FDK's new more environmentally friendly NiMH battery. Although these are advertised as charged and ready to go right out of the package, we recommend a forming charge period prior to use. The Twicell NiMH type has lower daily self discharge than typical NiMH cells. These cells have done well in our in house tests and I feel good about offering them for RC usage.
Be aware this cell is a newer product and does not have a deep record in the RC community. However, thus far they seem to be performing well. We offer them for your evaluation.
Overnight charging suggestion is stock factory wall wart 50-70mah or less.
Although FDK's website shows Cx1 (capacity x 1) fast charge rates with a NiMH rated charger, I'm not prepared to warranty any packs damaged by fast charging or peak charging in any form. If you insist on experimenting with fast charging and damage a pack, call FDK, not Radical RC.
FDK HR-3UTG Twicell Battery - 1.2 Volt 1900mAh AA Ni-MH Button Top ( extending ) Weight 99.5g, 3.5 oz.
Choose configuration below, "Flat" is 4 cells side by side, "Double Barrel Stick" is 2 cells end to end beside 2 cells end to end like a Double Barrel Shotgun.
 "FDK/Sanyo Twicell, 2000mah NiMH AA 4 Cell 4.8V Flat or Double Barrel Stick Pack")