Low-Cost NiMH Battery Charger
Created: Sep 01, 2014
No description available.
This design is a low-cost NiMH/ NiCd battery charger circuit, which is a complete independent constant current source used to charge up to three series cell NiMH or NiCd battery pack. The board uses the MCP1630 high-speed analog PWM and PIC12F683 to generate the charge algorithm for NiMH or NiCd batteries. Different battery chemistries can be charged using this circuit with minor modifications to its firmware or design.
It is used to evaluate Microchip's MCP1630 in a SEPIC power converter application. As provided, it is capable of charging a three series cell NiMH battery pack from an input voltage of 6V to 14V. The output is cable of charging at a fast charge rate of 1.3A constant current. It provides a constant current charge with preconditioning, cell temperature monitoring and battery pack fault monitoring. Also, the charger provides a status or fault indication. It automatically detects the insertion or removal of a battery pack.
The low-cost NiMH battery charger has the following features: overvoltage protection, overcharge protection, overcurrent protection, battery reversal protection, input short circuit protection, over temperature protection, ability to adapt to environmental effects, flexibility to optimize the charging algorithm for new battery technology, and different battery chemistries or different battery pack configurations.