# What Size Solar Panel to Charge 12volt Battery

Published on: December 8, 2021
Written by Liam Jaxon / Fact-checked by David Rowan

One of the common questions of solar panel users is what size solar panel to charge a certain size of battery. This is so much confusion for people, who want to install a new solar panel in their homes or vehicles or in other places.

As we can’t use a wrong-size solar panel to charge the battery. So, to get the right size solar panel for the 12V battery, we have to know about the solar panel size measurement.

Without knowing this we will not be able to choose the right solar panel for a 12v battery. Let’s talk about certain factors to choose the right size solar panel that is perfect to charge the 12V battery.

This article discusses the size of a solar panel to charge a 12-volt battery. All related answers on this factor you will get here. Get all knowledge in this field to solve issues.

## The Physical Size of the Solar Panel

Normally when we talk about solar panels, at first the residential solar panel comes to our mind. So, let’s start with the residential solar panel size. The typical size of a residential solar panel is 65 inches by 39 inches and some are 61.3 by 41.3 inches.

A solar panel is made of a number of cells. Most 12-volt solar panels have 36 cells. Now the manufacturers use crystalline silicon technology to make solar panels. And monocrystalline and polycrystalline are the materials of silicon technology.

Most manufacturers Use these two materials to create solar panels. The efficiency of solar panels depends on these two materials. You will know about this below in the efficiency of the solar panel.

In commercial space, the typical size of the solar panel is 78 inches by 39 inches. And this type of solar panel uses 72 cells in it. Some commercial solar panels have also up to 98 cells.

## Type of Solar Panel to Charge a 12-volt Battery

The type of solar panel you should use to charge a 12-volt battery depends on the specific application. Generally speaking, you should use a 12-volt solar panel with an amperage rating that is equal to or greater than the amperage rating of the battery you are charging. For example, if your battery has an amperage rating of 10 amps, you should use a 12-volt solar panel with a 10-amp or greater output.

## The Efficiency of Solar Panels

All solar panels are not made of the same materials. So, the efficiency of solar panels depends on the materials of the solar panels. Monocrystalline solar panels are more efficient to produce power than polycrystalline solar panels.

That’s why when manufacturers make polycrystalline solar panels, they use more cells in them to produce the same power as monocrystalline solar panels. Monocrystalline cells have 20% more efficiency to produce power than polycrystalline solar cells.

## Solar Panel Size for 12-volt Battery

In a general sense, a 12-volt battery needs the same volt solar panels to get the full charge. But When we are purchasing solar panels for the 12-volt battery we have to choose a solar panel that has more volts than the volt of the battery. For a 12-volt 100 a/h battery you will need a 150 watts solar panel.

If you install a solar panel that is 300 watts then it will produce the same power within half of the time. In the same way, if your battery is 12-volt 200 a/h then you will need 300 watts solar panel. And to improve the charging time you should use 600 watts solar panel.

This battery size mainly depends on the total ampere needed daily by your appliances. So, if Your appliances need less ampere, then you will need fewer watts of the solar panel system. But the volt will be the same as mentioned above.

## How Much Time Does Your Battery Need to Get Charged

It generally depends on the size of the battery the size of the solar panel and the total time of the sunlight. To get the answer if have to know how much power your battery needs to get fully charged.

If your battery needs 3 KW of electricity to run all the appliances, then you will need a battery that can supply 6 KW. Because you should only discharge 50% of the power. So, for a 12-volt battery that is rated at 100-amp hours, we will need a solar panel that can produce 6KW of electricity. If your solar panel system is 1KW then it can charge the battery within 6 hours of full sunlight.

So, this is how a solar panel can charge a 12-volt battery. The actual size of the solar panel depends on the size of the battery. You have to choose your solar panel on the basis of the size of the battery. Though the volt of the battery is an important factor to choose solar. But the most important factor is the size of the battery.

## Additional Components to Charge a 12-volt Battery With a Solar Panel

In order to charge a 12-volt battery with a solar panel, you will need an appropriate solar charge controller, wires, and a 12-volt battery. The solar charge controller will regulate the current and voltage from the solar panel to the battery to ensure that the battery is not overcharged. The wires will need to be rated for the current and voltage that the solar panel and battery will produce. The 12-volt battery should be of the type that can be charged and discharged safely and should be of the correct size to provide the necessary capacity and power.

## How Quickly Does a 100W Solar Panel Charge a 12V Battery?

Generally, a 100-watt solar panel can fully charge your 12-volt battery for around 2 to 4 hours. Although this charging time is dependent on the size of the battery, quantity of sunlight, quality of the solar panel, and more factors.

On the other hand, a 50Ah 12-volt deep cycle lead acid battery will need to take a minimum of 4 hours of open sunlight. If the battery is a larger size like 65ah capacity, it will require more current. So, you have to turn on 130 watts of solar panels to charge the larger battery within the same 4 hours.

Do you know what size battery 100W solar panel will change?

An individual 100-watt solar panel is fitted to charge a 12-volt 7AH battery. When you expect to use this process, you can divide 100W by 12 V. And, you get 8 amps. So,

• 8ah/7AH = 1.14 days to charge the battery bank

If you change a 12-volt 20AH battery using the same 100-watt solar panel, you get 8.3 amps while dividing 100 watts by 12 volts. So,

• 8.3ah/20AH = 0.42 days to charge the battery bank

It is the basic calculation. Keep in mind that you get a perfect result during the time of direct sunlight. By the way, if you have no idea how big a solar panel is, you would like to visit this blog post.

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