SolarBazaar

Charge Controllers

Browse 35 charge controllers — compare specifications across 15 brands.

Showing 24 of 35 products

Charge Controllers: what they do

SolarBazaar lists 35 charge controllers for United Kingdom, including ranges from Morningstar, Victron Energy and Steca. A solar charge controller sits between the panels and the battery, regulating voltage and current so the battery charges correctly and is never overcharged or drained back into the array at night.

In any system with a battery and a separate array, the controller is what protects the most expensive component and determines how much of the array's output actually reaches storage.

The specifications that matter

When you compare charge controllers on this page, these are the fields worth putting side by side. Anything else is secondary until these line up with the rest of your system.

  • type: MPPT or PWM
  • rated charge current in amps, which must exceed the array's short-circuit current with margin
  • maximum PV open-circuit voltage, the hard limit that must survive cold-morning Voc rise
  • supported battery voltages (12/24/36/48 V) and chemistries
  • conversion efficiency, typically 96–99% for a good MPPT unit
  • whether it offers a load output, temperature compensation and remote monitoring

How to choose a charge controller

  • Choose MPPT over PWM for anything beyond a very small array. An MPPT controller harvests roughly 20–30% more energy because it converts excess panel voltage into charge current instead of throwing it away.
  • Size the current rating from array watts divided by battery voltage, then add at least 25% margin for cold, bright conditions where panels exceed their rated output.
  • Check the maximum PV input voltage against the array's Voc at your coldest expected temperature, not at 25 °C — Voc rises as temperature falls, and exceeding the limit destroys the controller instantly.
  • Confirm the controller supports your battery chemistry with the right charge profile. Lithium, AGM, gel and flooded batteries need different absorption and float voltages.
  • Prefer a unit with temperature compensation or a battery temperature sensor if the bank lives somewhere that gets hot or cold.

Common mistakes to avoid

  • Sizing on rated array watts alone and ignoring the voltage ceiling, which is the most common way controllers are killed.
  • Using a PWM controller with a high-voltage grid-tie panel — the voltage mismatch wastes a large share of the panel's output.
  • Running the load output beyond its rating instead of wiring heavy loads directly to the battery through a fuse.

Frequently asked questions

MPPT or PWM — which charge controller should I buy?

MPPT for almost every case. It tracks the array's maximum power point and converts surplus voltage into extra charging current, typically delivering 20–30% more energy than a PWM controller from the same panels. PWM only makes sense for very small, low-voltage systems where the controller's cost is a large share of the total.

What size charge controller do I need?

Divide total array watts by battery bank voltage to get the approximate charge current, then add at least 25% headroom. A 1,000 W array on a 24 V bank needs roughly 42 A, so a 50 A or 60 A controller is the right choice. Also confirm the array's cold-weather open-circuit voltage stays under the controller's maximum PV input.

How many charge controllers are listed on SolarBazaar?

35 charge controllers for United Kingdom, from brands including Morningstar, Victron Energy and Steca. Listings are country-scoped, so the count changes when you switch country in the header.