The 3-stage MPPT Solar Charge Controller has features found on commercial units costing a great deal more. The design retains the features of maximum power point tracking (MPPT) for optimum power delivery from solar panels and 3-stage charging for lead-acid batteries. During bulk charging, maximum energy is extracted from the solar panel using the MPPT feature to charge the battery.
Bulk charging stops when the battery voltage reaches 14.4V. The absorption stage maintains the cut-off voltage of 14.4V for an hour ensuring the battery is fully charged before swithing to the float stage.
During the float charge stage the battery is maintained at a constant 13.5 volts. With the equalisation stage activated the the battery voltage is allowed to rise by 10% over the cut-off voltage to cause gassing within the cells. This ensures all the cells charge equally. This unit is designed for use outdoors or mounted as part of a vehicle based solar system.
Kit originally described in the March 2012 issue of Silicon Chip magazine.
Important Note For Kit Buyers:
This product is supplied in component form and requires soldering, drilling, and assembly. We recommend users are familiar with at least basic electronic principles and have the ability to solder.