Disclosure: This post may contain affiliate links.

Solar Panels: Which Fuse Between Battery & Charge Controller?

Find out which fuse is best between your battery and charge controller in your solar power system.

Solar Panels Jeremy Bezanger / Unsplash

Last Updated: November 17, 2022

Written by Brandon Jones

Fuse Size Between Battery and Charge Controller

Section Link

Below is a table showing which fuse size you should get based on the charge controller's amp rating.

For example, if you have a 20 amp charge controller, you should be using a 25 amp fuse on the cable between the battery and charge controller. The fuse for this cable should be close as possible to the battery on the positive wire.

Fuse - Battery to Controller
Controller Fuse Size Location (Positive)
20 amp 25 amp Close to battery
30 amp 35–40 amp Close to battery
40 amp 50 amp Close to battery
60 amp 75 amp Close to battery

To help buy new solar equipment, check out the Recommended Solar Equipment section below.

Learn more about setting up a solar panel system in my Simple Solar Panel System - Setup & Equipment Guide.

Answers to Your Other Solar Panel System Questions

Section Link

Be sure to check out the articles in our solar panel series to help answer your other questions:

Section Link

Here's our list of recommended equipment for the most common solar power systems.


Fuses protect the wiring and devices from overcurrent. Fuses usually go on the closest point of the positive connection from your battery to the power inverter. You can also put fuses elsewhere in your system for protection, like an MC4 fuse for going between your solar panel and charge controller. You can find MC4 Fuses on Amazon (affiliate link).


Batteries are used for storing the energy produced by your solar panels. The battery is wired between your power inverter and the charge controller. Never connect your power inverter and the charge controller directly without a battery between the two.

Charge Controllers

Charge controllers are used to regulate the voltage and current coming from the solar panels to prevent overcharging your battery.

Power Inverters

Power inverters are used for converting the battery's power (DC - direct current) into electricity used for powering your devices (AC - alternating current). Power inverters have an outlet on the device.

100W Solar Panel

Solar panels are made of many solar cells (photovoltaic cells), most often made from crystalline silicon. These cells take in energy from the sun's rays, converted through the semiconductor, creating an electric field that transfers voltage and current. Solar panels connect to the charge controller to regulate the voltage and current produced by the panel.

Solar Power System Cables

Branch Connectors

Branch connectors are for merging the cables coming from multiple solar panels to your charge controller.