This harness will connect two battery packs in series. You will effectively combine the voltages of the packs. Example: two 3S (11.1v) packs will have the output voltage of 6S (22.2v) when connected with this harness.

Note: You must always use identically prepared packs. Both packs must be fully charged and properly balanced. Both packs must be by the same manufacturer, have the same C rating, and both must have the same capacity and level of charge at all times.