MPPT vs PWM charge controller — which should I choose?

MPPT (Maximum Power Point Tracking) controllers are 20-30% more efficient than PWM and convert excess voltage into additional charging current. Choose MPPT for: systems above 200W, lithium batteries, or when panels run at higher voltage than the battery bank (e.g., 24V panel charging 12V battery). Choose PWM only for very small/budget systems under 200W. In Nigeria, MPPT worths the extra cost (₦35,000-₦150,000 vs ₦8,000-₦30,000 for PWM) for any serious home installation.

What size charge controller do I need?

Size your charge controller by: (1) total panel wattage divided by battery voltage gives amps. Example: 1,200W of panels / 24V battery = 50A controller. (2) Add 25% safety margin: 50A x 1.25 = 62.5A, so choose a 60A or 70A controller. Always check the controller's maximum PV input voltage — it must exceed your panel array's open-circuit voltage (Voc), especially in cooler harmattan mornings when voltage spikes. An undersized controller will overheat and fail.

Do I need a separate charge controller for solar panels?

Yes, you must have a charge controller between your solar panels and battery. Without one, panels will overcharge and permanently damage your battery. Some devices (solar generators, hybrid inverters) have built-in charge controllers — check specifications to confirm. If using separate components (panels + controller + battery + inverter), the charge controller is non-negotiable. It also prevents reverse current flow from battery to panels at night.

Can I use one charge controller for multiple solar panels?

Yes, one charge controller can handle multiple panels as long as the total wattage and voltage are within its rating. Connect panels in series (sum the voltages), parallel (sum the current), or series-parallel (mix). MPPT controllers handle higher input voltages efficiently, allowing you to wire more panels in series — reducing current through the wires and minimizing losses. For large arrays (3kW+), consider multiple parallel charge controllers for redundancy.