Charge Controllers for Solar Panels

Solar Charge Controllers

A solar charge controller sits between your solar panels and your battery bank. It regulates the power coming off the panels so your batteries charge fully without being overcharged, and it stops current from draining back into the panels at night. Krato Power carries MPPT and PWM controllers from 10A to 100A for RVs, cabins, and full off-grid homes, from brands including Rich Solar, SunGoldPower, Renogy, Outback Power, and EG4.

MPPT or PWM?

MPPT controllers convert extra panel voltage into extra charging current, so they harvest more power, handle higher-voltage panel strings, and are the right choice for lithium batteries and most systems over a few hundred watts. PWM controllers cost less and work well on small 12V setups where the panel voltage closely matches the battery, like a single panel on a trailer or boat.

How to size a charge controller

The rule of thumb: total solar watts divided by battery voltage, times 1.25 for a safety margin, gives the minimum amp rating. A 400W array on a 12V battery needs about 42A, so choose a 50A or 60A controller. The same array on a 24V battery needs about 21A, so a 30A controller works. Also confirm your panel string's open-circuit voltage stays under the controller's maximum input voltage, especially on cold mornings.

Controllers by system size

• RV, van, boat, and small 12V setups: Rich Solar BRAVO Waterproof PWM controllers from $26.99, and the Rich Solar 20A MPPT at $89.99.
• Cabins and mid-size 12V and 24V systems: Rich Solar BRAVO 40, 50, and 60 MPPT controllers from $159.99, the SunGoldPower 60A MPPT at $279, and the Renogy Rover 60A at $399.99.
• Off-grid homes and 48V systems: the SunGoldPower 100A MPPT at $495, the EG4 100A 500VDC MPPT at $556.97, the Outback FLEXmax 80 at $698.97, the Renogy Rover 100A at $701.99, and the Outback FLEXmax FM100 at $1,898.97.

Building the rest of the system? See our 48V Server Rack Batteries, 48V Inverters, and complete Solar Panel Kits. Not sure which controller fits? Call our team at 888-855-7286 for free sizing help.

Charge Controller Buying Guides

Start with our guides: MPPT vs PWM charge controllers and what size charge controller you need.