Abstract: A battery charging system is provided including a charger and a rechargeable battery of "standard" size and configuration. The rechargeable battery bears a special indicia that is sensed by the charger as a precondition to enabling the charging circuit of the charger. The indicia-bearing battery can thus be used in place of "standard" non-rechargeable batteries in battery using products of various sorts, but non-rechargeable batteries, lacking the special indicia, cannot be charged in the charger. Potential damage to the charger or product and other adverse effects associated with charging of non-rechargeable batteries is thus avoided.

Abstract: A battery charging system is provided which distinguishes between primary and secondary batteries by sensing a charging or discharging parameter of a battery placed into the system. A sensing means is included in the system which senses the value of at least one parameter of the battery. The parameter has a value for secondary batteries which is distinctive from its value for primary batteries. In response to an indication from the sensing means that the battery in the system is a primary battery, an enabling means disables charging of the primary battery by the system. The enabling means, in response to an indication from the sensing means that the battery in the system is a secondary battery, enables charging of the secondary battery by the system. One battery parameter which is particularly useful in discriminating between primary and secondary batteries is the low frequency impedance of the battery during charging.

Abstract: A controlled battery charger system is provided wherein a rechargeable battery is charged at a high charge rate and the voltage and temperature of the battery are both monitored by sensing means which are coupled to switching means to shut off the high charge-rate current when either the temperature or the voltage of the battery reaches a predetermined level.