How To Control Battery Charging Current. This voltage is sensed by GM1 through the 20-kohms resistor R3. Suppose 4 large batteries needs to be recharged at 500 mA rate from a 12 volt battery the resistor necessary could well be 12 - 4 x 12503 233 ohms or perhaps a twenty two ohms will be more appropriate.
Fast Charge Current Source Both Ni-Cd and Ni-MH are charged from a constant current source charger whose cur-rent specification depends on the A-hr rating of the cell. For example a typical battery for a full-size camcorder would be a 12V22A-hr Ni-Cd battery pack. The circuit is a 6V LM317 voltage and current control battery charger circuit which generates a regulated 6V DC output.
Lets say you have 9 1200mah cells discharged to 30V each.
Fast charge 1 to 2 hours Negative delta V NDV Cut-off charge system. This is the most popular method for rapid charging for Nicads. When charging you can leave your battery connected if youre using a trickle charger designed to retain your battery at a specific amount of charge for lengthy periods. Charging voltage and current control circuits for battery chargers provide for a constant output voltage above a predetermined value of charging current and a step-wise increased output voltage below the predetermined value of charging current.
