Collection: MPPT Charge Controllers

The oldest trick in solar hardware is a PWM controller with MPPT printed on the case. Buyers catch it two ways, and both figures are on every page here.

Two checks that expose a relabelled PWM

• The PV input window. A real MPPT accepts a panel string far above battery voltage — the controllers here take up to 160V open circuit and step it down. A PWM cannot: it drags the array down to battery voltage and throws the difference away.
• The weight. MPPT means an inductor, switching hardware and a heatsink, and those things weigh something. The 80A here is 2 kg (4.4 lb) and the 100A is 2.7 kg (6 lb). A 100A MPPT that weighs half a kilo is not an MPPT.

Sizing: controller amps times bank voltage

That product is the largest array the controller can carry. 60A on a 12V bank is roughly 720W of panels; the same 60A on 24V carries about 1,440W; on 48V, about 2,880W. Doubling your bank voltage doubles the array without buying a bigger controller, which is why most fixed installs move off 12V.

Then check the top of the PV window against the coldest morning of the year rather than today weather. Panel voltage climbs as temperature falls, and a string sitting at 140V in July can cross 160V in January and take the controller with it.

What is published, and who answers

Each page carries the full specification: PV voltage range, rated charging current, supported battery chemistries, dimensions and weight, including the figures that do not flatter the product. When a manufacturer does not publish a number, we leave it blank rather than inventing one.

Stock sits in US warehouses. Orders leave in 1-2 business days and arrive in 3-7, free shipping inside the US, 30 days to return it. Support is support@prestonsupply.com, read by a person and answered within one business day, Monday to Friday, 9am-6pm ET — before you buy, after you buy, and on the day something stops working.

Run your array through the sizing guide first, then pair the controller with a pure sine wave inverter.