There are many different sources of renewable energy available to power our electronics that are beneficial to our environment.

One of the main sources is the Sun. 

Solar panels capture energy from the sun and convert it to electricity which we can store and use later to power devices.

Solar lights utilise solar panels and the sun’s energy to light up spaces during the night time. They are commonly found in front and backyards of homes helping illuminate paths, as well as providing great ambience.

But, some of the time solar lights come with batteries that have a low capacity (denoted by the symbol mAh), which don’t last very long.

So, can you use a higher mAh battery in solar lights? Yes, you can use a higher mAh battery in solar lights to extend the hours that it stays on during the night. You will just have to make sure the dimension (size), as well as the voltage of the battery you are using matches the original solar light battery dimension and voltage which you are replacing. 

Deeper look at the rechargeable battery and its mAh rating

Solar lights are a great addition to any front or backyard. They can add a path of illumination when you return home during the night, or add some flare to your garden.

The main components of a solar light include;

  • Solar panel
  • LED (Light Emitting Diode)
  • Charge controller
  • Rechargeable Battery

The main component we are concerned with when asked the question of whether you can use a higher mAh battery is of course, the rechargeable battery.

So, let’s take a closer look at the rechargeable battery.

The mAh rating of a rechargeable battery used in solar lights

Rechargeable batteries have the ability to be recharged and used again to power electronic devices.They differ from standard one use batteries (disposable batteries) which need to be disposed of when they run out of charge.

There are many different varieties of rechargeable batteries available. Below are few of the characteristics which vary from one rechargeable battery to the next;

  • Chemical Composition (Li-Ion, NiMH, NiCD, Li-Ion polymer)
  • Size
  • Shape
  • Recharge rate
  • Discharge Rate
  • Capacity (milli-Ampere-hours → mAh)

The capacity (mAh) of the battery is the main characteristic of the rechargeable battery that we will focus on. 

The mAh rating is how much charge a battery is capable of storing. 

The rating of how much a battery can store is given by milli-Ampere-hours (mAh) or Ampere-hours (Ah). For the rest of the article I shall refer to the capacity as mAh.

The mAh rating is used for batteries with lower capacities, while larger batteries used the Ah rating. 

A note to make is how long a battery will last also depends largely on the current draw of whatever the battery is powering. Powering a motor is going to require more current than a LED for example. 

Looking at a practical example will give you a better understanding of how battery capacities work.

Below we have two batteries (battery A and battery B), both with different capacities. There is also an LED that will be the component that the batteries will be powering (which draws a current of 20mA).

Scenario 1: The LED is being powered by Battery A (500mAh). Since we know how much current the LED draws, we can calculate how long the battery lasts for. 

Below is the equation to calculate how long a battery will last depending on how much current is being drawn. The time is given in hours.

If we take Battery A’s capacity (500mAh) and divide it by the current draw of the LED (20mA), we get 25 hours. So, we know using a 500mAh battery can power a LED that draws 20mA for 25 hours (in an ideal world). 

An important note to make is the units you are using when doing these calculations. 

If you are using mAh ratings, then the current draw of the device you use in the calculation will have to be in mA. If the Ah rating is used, then the current draw used in the equation will have to be in A. Or, you could convert the Ah rating to mAh by dividing it by a 1000.

Scenario 2: The LED is being powered by Battery B (1000mAh).

Now, we are powering the LED with a 1000mAh capacity battery (an increase of 500mAh). So, taking Battery B’s capacity (1000mAh), and dividing it by the current draw of the LED (20mA), we get 50 hours.

As you can see, by increasing the mAh rating or capacity of the battery, we can increase the time the LED stays on for.

Can you use a higher mAh battery in solar lights?

Now that we know a little bit more about batteries and their mAh rating let’s look at whether we can replace a smaller mAh battery with a higher mAh one. 

Replacing the rechargeable battery that comes standard with a solar light depends on a couple factors.

Factors you need to consider before using a higher mAh battery for solar lights

Replacing a smaller capacity rechargeable battery with a higher capacity one can be done, but there are a couple of factors that need to be considered before doing so. 

Factor #1 when using a higher mAh battery for a solar light: Voltage 00

The first factor you will need to consider when replacing the standard battery of the solar light with a higher mAh one is the voltage of the battery.

The solar light will have a maximum voltage rating that it can handle (which is largely determined by the voltage rating of the Light Emitting Diodes).

You will have to make sure the battery you choose does not exceed these maximum ratings as you could run the change of damaging components.

Also, if you choose a low voltage battery, you will not be able to provide enough power to run the Light Emitting Diodes.

Factor #2 when using a higher mAh battery for a solar light: Size  

The next factor to consider is the size and shape of the battery (physical dimensions).

Rechargeable batteries come in a variety of shapes and sizes. Below are the most common sizes of rechargeable batteries:

  • AAA
  • AA
  • 14500
  • 16340
  • 18650
  • 26650
  • Coin Cell
  • D cell
  • C cell

Solar lights also vary in shape and size and therefore use different types of rechargeable batteries. You will have to make sure the battery you are replacing the standard one with, matches it in size.

Can a smaller sized battery have higher mAh ratings? 

You might be wondering if it is possible for the same size battery to come in a higher mAh rating even though its physical dimensions haven’t changed. 

The answer is Yes. 

As there are different chemical compositions of batteries available, you will be able to find a battery of higher mAh rating while still matching the size of the battery you are replacing in the solar light.

Advantage of using a higher mAh battery for solar lights 

Why would you want to replace the standard battery in solar lights with a higher mAh battery?

Using a higher capacity battery comes with some notable advantages.

As you saw earlier with the LED example and the two batteries of different mAh ratings, as you increase the capacity of a battery, you increase the amount of hours that the LED can stay on for. 

I chose that example specifically for this article as it applies to solar lights. 

Solar lights come with stock rechargeable batteries with very low capacity, that almost run out in an hour or two.

Increasing the battery mAh rating will mean that the solar light will stay on longer during the night. 

The next advantage of using a higher mAh rating battery is on days when there is not sunshine. You might have one day of sunshine and the next is cloudy.

If the battery mAh rating is considerably large, and the LED of the solar light does not consume a lot of current, you have the advantage of running the solar light two nights in a row with only one day of sunshine (but this does also depend on how much current the solar panel can provide as well as the exposure to sunlight).

Disadvantages of using a higher mAh battery for solar lights

One of the biggest drawbacks of using a battery with higher capacity is that it is going to take longer to charge the battery to full capacity.

I mentioned above that you could possibly run the solar light for two nights after only charging it for only one day under the sun.

However, it takes more for that to happen. The solar panel will need to be able to provide enough current to charge the battery to full capacity for the limited time the sun is out for. 

Also, the sun changes its position during the day, so the solar light will need to be placed in a location where it is exposed to the right amount of sunlight.  

Main purpose for using higher mAh battery in your solar lights 

Changing the current battery of your solar light depends on your needs. If you need to increase the time that the solar light stays on during the night, it makes sense to use a higher mAh battery as standar solar light batteries tend to be lower in capacity.

Just be aware that if your solar panel does not provide adequate current, that it is going to take a longer time and a lot more sunlight to recharge your battery to full capacity. 

What are the most effective mAh rating batteries for solar lights?

A battery with too high a mAh rating might take too long to charge, while a battery with a lower mAh rating might run out too quickly.

So, is there an ideal mAh rating that will be the most effective for your solar lights? 

This all depends on factors that we have mentioned earlier like sunlight exposure, and output current of solar panels.

If you have a solar light and are just changing the battery, you will need to check what the average current your solar panel outputs during a standard sunny day. 

Placement of the solar light should be of great importance. 

Accordingly, you can choose a rechargeable battery that is in the ‘sweet spot’ of being fully charged, and lasting a long time depending on the current your solar light panels provide.

Can you use non-rechargeable batteries in your solar lights?

Solar lights are meant to be self-sufficient. This means they can run by themselves without you having to do anything to operate them.

You can use non-rechargeable batteries (disposable batteries), however, you will have to dispose of them after they have run out of charge, because, well you cannot recharge them. 

Solar lights are named as they are due to the fact that they use solar energy to charge rechargeable batteries. Using disposable batteries would be paradoxical. 

How to change battery in your solar light 

Below is a great video highlighting how to replace solar light batteries. While your solar light might not be the same, the principle is the same for all solar lights.