Charge A 6 Volt Battery with a Solar Panel (Here’s How)

Do you need to learn how to charge a 6-volt battery with a solar panel? If so, the good news is that it is pretty easy, and you have a few options for how you go about charging 6-volt batteries.

A typical battery charging issue is that the solar panel may have too high a voltage to charge a 6-volt battery safely. Thankfully, there are solutions that we go over below.

In this article, we discuss:

  • The differences between voltage and charging
  • Solar regulators
  • Different types of regulators as they apply to real-life settings
  • How to Connect a solar panel to a battery charger

Can You Charge a 6-Volt Batter with a 12-Volt Charger?

The short answer is that you can charge a 6-volt battery with a 12-volt charger. So, what’s the catch? The catch is that it can be dangerous to do so. On the other hand, you cannot charge a 12-volt battery with a 6-volt charger.

There is no danger in trying to charge a 12v battery with a 6v charger. There is not enough electricity involved to fill the 12v battery.

The first lesson is that smaller voltage-rated chargers do not provide enough energy to charge larger voltage-rated batteries.

So, for example, you cannot use a six-volt charger to charge a twelve-volt battery.

The second lesson is that the process can be dangerous while using a larger rated voltage device to charge a smaller voltage rated better.

For example, using a twelve-volt solar panel to charge a six-volt battery can lead to permanently damaging the battery, exploding, or causing a fire.

What Is The Best Solar Panel to Charge a Six-Volt Battery?

Ideally, the best solar panel to use to charge a six-volt battery is a six-volt solar panel. Because solar energy ebbs and flows throughout the day, the panel will deliver less than six volts of current at its weakest power production.

The solar panel will provide a little over 9 volts at its peak.

Given that a six-volt battery is 100 percent charged at around seven volts, the pairing of the panel to a battery works when both are six volts.

While that sounds good news, it is not always a good fit. Are we talking in circles? Nope, and here’s why.

  1. Without a charge regulator, the panel will continue to charge the battery, even when the battery is full. The term for this is “overcharging,” which can be dangerous.
  2. When overcharging occurs, it causes the battery to heat up, which can destroy electrolytes. If overcharging occurs for too long, the battery will get hot and could ignite or explode.
  3. Without a diode, a solar panel can extract energy from a battery when the sun goes down. When the flow of energy reverses, we call that “backflow.”

There is a way to correct these issues and prevent overcharging safely and backflow. The little tool that achieves this is called a solar regulator, also called a charge controller.

Before we look at how to charge a 6v battery, we must understand what regulators do.

solar charge controller

See also: How to Charge a Battery with a Solar Panel: A Comprehensive Guide for Beginners

What Does a Charge Regulator Do?

In short, a solar charge controller or a solar regulator limits the amount of energy from an array to its components, especially for Solar Battery Storage Systems.

They also prevent the backflow of electricity when the sun is not shining. A solar charge regulator or controller will solve issues of overcharging and backflow.

Ready for more good news? A solar regulator is family inexpensive.

Is A Solar Regulator Essential?

You can charge a six-volt battery directly without a solar regulator, but you do so at significant risk. A solar regulator on the cheaper end is around $50.

However, the regulator’s cost is minimal if you use the solar panel to charge the battery over many years.

Solar regulators are an essential part of a solar array, even if the array is a single panel. In addition, some devices have regulators already built into them or their charging cords.

Therefore, it is essential to know if your device or its charging cord has a built-in regulator.

Are There Different Types of Solar Regulators?

There are different types of solar regulators. They are PWM — Pulse With Modulation and MPPT or Maxim Power Point Tracking regulators, and they work differently.

PWM Regulators — The keyword here is PULSE. As energy comes from the panel to the PWM regulator, it either lets the energy pass or shuts off the energy flow.

It does this many times per second. To determine allowing the battery to charge or not, the PWM regulator measures the battery voltage to see if the battery is fully charged or not. That process keeps the panel from overcharging the battery.

MPPT Regulators — work with voltage converters, and they work to help the panel produce the most power possible.

These are handy because sunlight is variable throughout the day. An MPPT regulator can make a poorly performing solar panel — low light conditions — produce the most energy possible.

It still allows battery charging to occur safely but also maximizes the panel’s power, leading to faster charging times.

Charge controller mounted on the wall

Which Type of Regulator Do You Need?

Either PWN or MPPT type of regulator works well. If you are camping and hiking, an MPPT regulator is ideal.

Since you experience different weather and light conditions, the MPPT regulator will give you the most power in the worst conditions. That is a positive, especially if you have a short time to charge batteries.

If you are in a more stable lighting environment, the PWT is a good option. The PWT regulator is excellent for smaller solar charging systems.

They are generally a little less expensive than the MPPT regulators. For backpacking, where weight is an issue, you would probably go with a single panel and PWT regulator.

An MPPT regulator with a more extensive solar array would be excellent for off-road adventures and remote camping adventures. Both regulators will help the solar panel charge your six-volt battery and do that safely.

Another consideration for charging batteries with a solar panel is a battery backup bank. While charging a single battery, you can also charge a battery bank. The energy in the bank will allow you to charge your devices when the solar panel is inactive.

Many battery banks are small enough to carry in your backpack and are fantastic because you can charge your phone, for example, while you are hiking and not using the phone.

You can also use the battery bank to charge your device overnight while you sleep. Another plus of a 6v battery backup bank is that many have multiple ports giving you the option to charge more devices simultaneously.

12 Volt Battery White background

How To Charge A 6v Battery with a Solar Panel

1. Assemble your Parts — You will need a 6v solar panel, a 6v battery charger, a solar regulator — PWT or MPPT, a voltage meter with DC setting, tools such as screwdrivers or pliers, and a cap or electrical tape to seal the connections.

Sometimes all of these pieces will come with snap clips. If so, make sure the clips are compatible. If not, you may have to splice wires.

2. Test the solar panel with the voltage meter to measure the panel’s output and ensure it is working.

3. Connect the solar panel to the solar regulator—positive wire to positive lead and negative wire to negative lead. Usually, red wires are positive and black wires are negative.

4. Connect the solar regulator to the battery charger.

5. Power up the system and test the battery charger with the voltage meter to measure the energy levels from the panel to the charger. It should be in the 6-9v range.

6. Add the battery(s) to the charger.

The solar regulator will keep the batteries charging until they are complete. Then, power down the system and remove the batteries.


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Elliot has 20+ years of experience in renewable technology, from conservation to efficient living. His passion is to help others achieve independent off-grid living.

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