Five-cell A123 battery packs (5s) with a nominal voltage of 16.5V. All of our A123 packs are produced using genuine A123/LiFe cells from A123Systems.
When charging A123 battery packs comprised of five cells do not charge above 18.0V.
When using 5s A123 packs in your RC model, do not discharge below 12.5V, this will ensure a long service life. Discharge to 10.0V is within spec but be aware that the power-drop for A123 batteries is abrupt in comparison with LiPo batteries.