Constant Current Source

The simplest way of charging a NIMH battery is to charge at C/10 or less (10% of the batteries rated capacity per hour). So a 3000mAH battery would be charged at 300mA for 15 hours. At this rate, the battery can't be over charged.

This circuit is suitable for charging a 10 cell 3AH NIMH battery pack. As the charge rate is less than 0.1C (300mA) the battery should be charged over a period of approximately 15 hours.

The Digital panel meter enables the battery voltage to be monitored while charging. The battery will be fully charged when the voltage reaches approximately 14.1V (1.41V per cell)

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