Charge 4 single-cell lipo batteries at once - with a regular hobby charger.Fits the 205mAh packs with PH2 connector. This adapter is made with the finest ingredients and with great attention to detail. The best plugs, the thickest wire, and a high quality silicon coating. CAUTION It is best practice to have all packs near the same voltage when parallel charging. A full discharged pack and a nearly charged pack on the board at the same time should be avoided. Instructions:- plug cable into charger- connect 4 discharged batteries- charge at 1S voltage and combined 1C current For 4x 205mah batteries, the combined capacity is 820mah, so a 1C charge rate would be 0.82A. You can charge these packs with up to 2C (1.64A), but to maximise life time, 1C is better.