Abstract: The present disclosure is directed to a battery charger for charging a connected battery pack. The battery charger is capable of determining an impedance characteristic value of the battery pack and adjusting a charging scheme, including an initial and/or subsequent charging rates for the battery pack based on the determined impedance characteristic value. The present disclosure is also directed to a method of charging a battery pack. The method includes determining an impedance characteristic value of the battery pack and adjusting a charging scheme, including an initial and/or subsequent charging rates for the battery pack based on the determined impedance characteristic value.

Abstract: The present disclosure is directed to charging a battery pack by measuring an electrical impedance value of a battery pack by applying a sinusoidal AC excitation signal to a plurality of battery cells of the battery pack, measuring a total impedance value of the battery pack, obtaining a chemical impedance value of the battery pack based on the electrical impedance value and the total impedance value, and adjusting a charge current applied to the battery pack based on the chemical impedance value of the battery pack.

Abstract: The present disclosure is directed to charging a battery pack by determining a battery pack identification (ID) value from a battery pack identification (ID) component of the battery pack, applying a sinusoidal AC excitation signal to a set of battery cells of the battery pack, calculating an impedance value of the battery pack based on the sinusoidal AC excitation signal, comparing the impedance value of the battery pack to a set of reference impedance values associated with the battery pack ID value, and selecting a charging scheme based on a comparison of the impedance value of the battery pack to the set of reference impedance values associated with the battery pack ID value. The battery pack is charged using the charging scheme.

Abstract: The present disclosure is directed to a battery charger for charging a connected battery pack. The battery charger is capable of determining an impedance characteristic value of the battery pack and adjusting a charging scheme, including an initial and/or subsequent charging rates for the battery pack based on the determined impedance characteristic value. The present disclosure is also directed to a method of charging a battery pack. The method includes determining an impedance characteristic value of the battery pack and adjusting a charging scheme, including an initial and/or subsequent charging rates for the battery pack based on the determined impedance characteristic value.

Abstract: The present disclosure is directed to a battery pack and a power tool system including a power tool, a battery pack and a battery pack charger. The battery pack includes circuitry to prevent electricity drainage from a plurality of battery cells when the battery pack is only partially mated to the power tool or the battery pack charger.