Seven-cell A123 battery packs with a nominal voltage of 23.1V.
All of our A123 packs are produced using genuine A123/LiFe cells from A123Systems.
When charging A123 battery packs comprised of seven cells (7s) do not charge above 25.2V (3.6V per cell)
When using 7s A123 packs in your RC model, do not discharge below 17.5V, this will ensure a long service life. Discharge to 14.0V is within spec' but for flying models, the power drop-off is quite abrupt compared with a LiPo battery.