Solar Panel Wiring Guide

Learn how to wire solar panels and batteries together to get the effect you want in your solar-powered home. Be sure to follow proper protocols and safety tips to avoid electrical injuries.

Solar Panel Wiring

We’re going to show you how to DIY wire solar panels and batteries together so that you can increase those watts, volts, and amps as you need.

More specifically, we’ll show you the exact solar panel and battery arrangements that you can use – with different watt, volt, and amp totals so you can get a good idea of what’s available from each arrangement VS your specific “watt, volt and amp” needs.

This way you can choose the system that’s best for you.

For instance:

• If the appliances you want to power are rated high in voltage, then you’ll want to pick a PV panel wiring arrangement that has high enough volts (push) to power those appliances.
• Similarly, if you have fewer daylight hours available and want to charge your batteries faster to take advantage of the sun while it’s around, you would probably benefit from a solar system wiring arrangement with higher amps (current speed/intensity).
• Or if you want to power many, many different appliances you’ll need to make sure your solar system not only produces many watts but also has enough volts for the big appliances, enough amps to charge fast enough, and enough batteries to hold the big load.

By understanding how many watts, volts, and amps are created by each solar wiring arrangement, you can better choose the solar inverter and overall system with the balance of everything that’s right for you.

After picking which system best suits your needs (and buying or building the solar panels needed), you can connect your solar panels/batteries as shown and even add more over time. In fact, you can pick one of the smaller systems (we show you) for now, add to it gradually, and eventually turn it into one of the bigger systems over time.

It’s just a matter of adding more panels or batteries and switching the wiring to match the bigger system by following the exact wiring in the example arrangements.

We are going to start by showing you some smaller solar systems (arranged in different ways to produce different results) and move on to bigger solar systems (arranged in different ways to produce different results). You can change the wiring as you add to your system over time.

Remember, you don’t need to start by making all the solar energy you’ll ever need, right away. You can get your feet wet by setting up your first solar system successfully, save a little bit of money, then do it over and over again as many times as you want.

How To Wire Solar Panels

You Decide What You Want, Then Build It

Setting up a solar system requires some thought before you even start wiring solar panels together. You must decide what factors are important to you, your available time and budget as well as how much stress you want to put on your solar system.

In the end, it’s always better to balance your system out so that the volts and amps are not very far apart. The greater the difference between your volts and amps, the more stress you put on your batteries and the shorter your batteries’ lifespan will be.

However, sometimes it’s necessary to pick a solar PV panel wiring arrangement that increases your volts or amps but also puts stress on your battery bank. You would typically do this if you didn’t have the budget or space to use a lot of solar panels and you wanted to raise the volts or amps to a certain level by using straight series or straight parallel wiring.

Solar Wiring How Stress Affects Your Battery

When learning how to wire solar panels, it is imperative that you understand how stress as a result of an unbalanced system can affect your battery bank’s overall lifespan.

Although each solar battery has its own specs, the general examples below can give you some idea.

Low-Stress Example:

With a well-balanced solar arrangement (volts and amps are not very far apart), your batteries should last 7 to 10 years (using batteries with a 10-year life span).

High-Stress Example:

With a solar arrangement that’s not well balanced (volts and amps very far apart) your batteries should last about 3-5 years (using batteries with a 10-year life span).

Choosing The Correct Wire Gauge (Size)

The type and size of wire you use for wiring solar panels and connecting all the different components in your solar system play a big role in the effectiveness and efficiency you’ll get out of it. It can also make the difference between damaging your system unknowingly and not.

Do Not Mix Used Batteries With New Batteries

It’s also important to note that unlike when wiring solar panels, it’s not a good idea to add more batteries to a battery bank after the batteries in that bank have been used. In other words, all the batteries in your system must be equally used and all have the same remaining usage cycles in order for you to get the best results from your system.

Sure, people break this rule all the time, but it is not the healthiest thing to do to your PV system. If you’re going to start with a smaller system and add to it as you go, I suggest you wait until you have completely used up your batteries’ life span with the smaller system and then buy all new batteries when you upgrade to the bigger system with more panels.

When it comes to deciding on the size of your battery bank, make sure you match your battery bank size to the solar panel array size. After determining your load requirements, build a battery bank that’s big enough to store five days’ worth of power plus another 30%. This extra 30% is to allow for changes and fluctuations in battery capacity due to temperature and other factors.

Using Bigger Solar Panels

One way to get around having to stress your system (or having to join many panels together) in order to bring up your volts, amps, or watts, is to use more powerful solar panels. With more powerful solar panels, large or complex PV panel wiring becomes less necessary.

To make more powerful solar panels all you have to do is buy more powerful solar cells. This will bring up your watts, volts, and amps so you don’t have to do so much joining and balancing of solar panels.

If you really want to make a bigger (more powerful) solar panel with the materials available today, I would suggest substituting the solar cells used in the examples on this page with mono crystalline solar cells rated at 41 Volts and 5.49 Amps. If you use 72 of these solar cells to make one panel your one finished panel will be able to deliver 225 Watts of power maximum in optimal sunlight.

Solar Wiring Guide

How to join your solar panels & batteries together with the different results (watts, volts, amps) created.

Now that you have reached the solar wiring diagrams section of this website, you are finally ready to learn how solar panels and batteries are wired together.

We are going to start with showing you some smaller solar systems (arranged in different ways to produce different results) and move on to bigger solar systems (arranged in different ways to produce different results). Each arrangement has its own solar wiring diagram, so you can see exactly how it’s done.

Remember, you don’t need to start off by making all the energy you’ll ever need, right away. You can get your feet wet by setting up your first solar system successfully, save a little bit of money at first, then do it over and over again as many times as you want!

Ok, let’s look at some solar system arrangements YOU CAN COPY:

1 Panel Solar System

Although a one-panel system above wouldn’t provide an awful lot of power, (certainly not enough to meet all your needs), it could be used to supplement some energy, save you a little bit of money, and provide some limited convenience.

An arrangement like this would typically be used in a portable application powering appliances with low power ratings, like those often used in trailers and RVs.

For instance, if you have a certain appliance you would like to power like a laptop by the pool or a TV in your backyard shed or gazebo, then this type of solar application would provide a good affordable (but limited) energy solution.

Solar Panel Wiring Usage and Limitations

Watts – The reason why this arrangement is limited is that with only one panel, you can only produce up to 63 watts per hour maximum (under optimal sunlight conditions).

Battery – With only one battery, you can only store one battery worth of power. Since your battery can store 105 amp hours (105 amps total in one hour) worth of energy, you’ll have to spread those amp hours out according to the amp rating of your appliance for as long as you can. If you stick to small appliances with small power loads you should be able to get some minimal energy savings with this system in optimal sunlight.

That might seem great but if you started adding more appliances and power loads, you would likely run out quickly. Also for the health and life span of your battery, you should try to never discharge your batteries more than 30% empty. As a result, this limits your available power even more.

Amps – Furthermore, your system would only have 3.5 amps (of current speed) so you would be producing power or charging your battery kind of slow.

Volts – And with only 18 volts (panel) and 12 volts (battery bank), you would only be able to charge appliances with a lower voltage rating, like 12 volt but not 24 volt or higher.

But don’t get too discouraged, this solar arrangement is still useful and practical, as long as you don’t expect too much out of it.

2 Panel Solar System

The second solar power wiring diagram (arrangement) we’ll look at consists of two solar panels and a battery bank with two batteries in it.

With a two-panel solar arrangement, we have a few more options in terms of wiring. We now have the choice of wiring our two panels (and batteries) using series wiring or parallel wiring.

Series wiring is when you connect your panels (or batteries) positive to negative, negative to positive, etc and it is used to increase the overall volts.

Parallel wiring is when you connect your panels (or batteries) positive to positive, negative to negative, etc and it is used to increase the overall amps.

Here is an example of the same two panels wired in both series and in parallel. If you’re going to be using two solar panels/batteries in your system, you can follow one of the diagrams below, depending on what’s more important to you: Volts (so you can power bigger appliances) or Amps (so you can charge your batteries faster). 

With this small amount of solar panels/batteries, we can’t do a combination of both, so it’s either one or the other. Although the two solar arrangements above don’t offer the most power or storage capacity, (certainly not enough to meet all your needs), they do give you more to work with.

For instance: With the “series” arrangement above, you could now power a 24 volt appliance and wouldn’t have to stick only to low voltage appliances commonly used outdoors in trailers or RVs. 

However, if you are using appliances with low voltage ratings anyway (like if you’re in a camper) then you might prefer the “parallel” arrangement because you’ll be able to charge your batteries faster and store more energy per available daylight hours.

Solar Wiring Usage and Limitations

Watts – Since we are now working with two panels, this solar system will output 144w of power per hour maximum (under optimal sunlight conditions). Still not the most power, but much better than the one-panel system in our first example. The watts remain the same with both series and parallel wiring.

Battery – With two solar panels and two batteries wired in series, your battery’s storage capacity stays the same: 105 amp hours – so your battery can store 105 amps total in one hour. This is a low storage capacity.

Amps – With two solar panels and two batteries wired in series, your amps remain the same at 3.5 amps so you won’t increase your charging speed.

Volts – With two solar panels and two batteries wired in series, your panels’ volts increase to 36 volts and your battery bank’s volts go to 24 volts which means you’ll be able to power up to 24 volt appliances.

Parallel Wiring – Two Panel Solar System – Usage and Limitations

Watts – Since we’re now working with two panels, this solar system will output 144w of power per hour maximum (under optimal sunlight conditions). Still not the most power, but much better than the one-panel system in our first example. Watts remain the same with both series and parallel wiring.

Battery – With two solar panels and two batteries wired in parallel, your battery capacity increases to 210 amp hours – so your battery can store/spend 210 amps total in one hour. This gives you better storage capacity, but the trade-off is that your battery bank’s voltage remains small at 12 volts. If you stick to small appliances with small power loads, you should be ok.

Amps – With two solar panels and two batteries wired in parallel, your amps increase to 7 amps which means you’ll be able to charge your battery bank faster and take better advantage of available daylight hours.

Volts – With two solar panels and two batteries wired in parallel, your volts remain the same at 18 volts (panels) and 12 volts (battery bank) so you will only be able to charge a 12 volt battery bank and thus power up to 12 volt appliances.

Although there are still many limitations with the two panel /battery arrangement (series & parallel) discussed above, there are also some advantages that you can benefit from. 

If you are only supplementing some of your home’s power or using your system to power RV-type appliances, then this arrangement allows you to pick a balance that can be more practical to your needs.

4 Panel Solar System Wired in Series & Parallel

The next solar power wiring diagram (arrangement) we’ll look at consists of four solar panels and a battery bank with four batteries in it.

With four panels, we have enough of them to arrange them using a combination of series and parallel wiring. We do this because it provides a better balance of volts and amps, instead of tipping the scales only to one side (like with just straight series or straight parallel wiring).

Here is an example of four panels wired in a combination of series and parallel. If you’re going to be using four solar panels/batteries in your system, you can follow the diagram below for a good balance of volts, amps, and watts.

Although the solar arrangement above isn’t the biggest, it does provide reasonable amounts of power, load delivery, and storage capacity.

With the series/parallel arrangement above, you can now power a 24 volt appliance, while charging your batteries faster (7 amps) thus storing more energy per available daylight hours, plus you get 210 amp hours of storage capacity.

Solar Wiring Usage and Limitations

Watts – Since we connected two groups of two panels together in series and parallel, this solar system will output 252w of power per hour maximum (under optimal sunlight conditions). This is an ok amount of power and you should start to notice some better energy savings now, however, this setup still has its limitations.

Battery – With two groups of two panels/batteries wired in series and parallel, your battery capacity increases to 210 amp hours – so your battery can store/spend 210 amps total in one hour. This is a better storage capacity.

Amps – With two groups of two panels/batteries wired in series and in parallel, your amps increase to 7 amps which means you’ll be able to charge your battery bank faster and take better advantage of available daylight hours.

Volts – With two groups of two panels/batteries wired in series and in parallel, your panels’ volts increase to 36 volts and your battery bank’s volts go to 24 volts which means you’ll be able to power up to 24 volt appliances.

While this four-panel series / parallel arrangement helps to add some balance to our solar system by bringing the volts and amps up to an acceptable level, it’s still not enough power to give us an awful lot of flexibility or freedom. For instance, we still can’t power 48 volt appliances.

But let’s see what happens if we wire four panels in series.

4 Panel Solar System Wired in Series

Now we’ll look at the same four-panel solar arrangement as above, except we will wire the panels and batteries together only in series.

Although this system is not necessarily one that many would use (most would likely prefer the previous more balanced system because more balance extends battery life), the main reason for somebody choosing this arrangement would be to increase the volts high enough to power 48 volt appliances. Of course, you will be sacrificing some amps (charging speed), and amp hours (storage capacity), but if powering up to 48 volt appliances is what you want, you will accomplish this.

Here is an example of four panels wired in series. If you’re going to be using four solar panels/batteries in your system, it’s better to use the more balanced previous example, but if you absolutely need to power 48 volt appliances on a tight budget, this is how to do it.

Although the solar arrangement above isn’t the best for the long term life of your battery because there is more stress on the system, it does provide a way to reach the capability of a bigger system without having to add more panels/batteries.

With the series arrangement above, you can now power a 48 volt appliance, but you’ll charge your batteries slower (3.5 amps), making less energy per available daylight hours, plus you only get 105 amp hours of storage capacity.

Solar Wiring Usage and Limitations

Watts – Since we connected four panels together in series, this solar system will output 252w of power per hour maximum (under optimal sunlight conditions). This is the same wattage as the previous 4-panel system and has an ok amount of power. You should start to notice some better energy savings now, however, this setup has its limitations.

Battery – With four panels/batteries wired in series, your battery capacity stays at 105 amp hours – so your battery can store/spend 105 amps total in the period of one hour. This is a low storage capacity.

Amps – With four panels/batteries wired in series, your amps remain at 3.5 amps which means slower charging speeds and you won’t be able to take full advantage of available daylight hours.

Volts – With four panels/batteries wired in series, your panels’ volts increase to 72 volts and your battery bank’s volts go to 48 volts which means you’ll be able to power up to 48 volt appliances.

While this four-panel series arrangement helps to tilt the scales in the voltage favor, it also decreases some other very important factors that you may not want to give up. The choice is yours.

8 Panel Solar System Wired in Series & Parallel

The next solar power wiring diagram (arrangement) we’ll look at consists of eight solar panels and a battery bank with eight batteries in it.

With eight panels we clearly have enough of them to arrange them using a combination of series and parallel wiring. We do this because it provides a better balance of volts and amps, instead of tipping the scales only to one side (like with just straight series or straight parallel wiring).

Here is an example of eight panels wired in a combination of series and parallel. If you’re going to be using eight solar panels/batteries in your system, you can follow the diagram below for a good balance of volts, amps, and watts.

With the series/parallel arrangement above, you can now power a 48 volt appliance, while charging your batteries fast (7 amps) thus storing more energy per available daylight hours, plus you get 210 amp hours of storage capacity (which is better than 105 amp hours).

Solar Panel Wiring Usage and Limitations

Watts – Since we connected two groups of four panels together in series and parallel, this solar system will output 504w of power per hour maximum (under optimal sunlight conditions). This is a good amount of power.

Battery – With two groups of four panels and batteries wired in series and parallel, your battery capacity is at 210 amp hours – so your battery can store/spend 210 amps total in the period of one hour. This is a pretty good storage capacity.

Amps – With two groups of four panels/batteries wired in series and in parallel, your amps are at 7 amps which means you’ll be able to charge your battery bank fast and take better advantage of available daylight hours.

Volts – With two groups of four panels/batteries wired in series and in parallel, your panels’ volts increase to 72 volts and your battery bank volts go to 48 volts which means you’ll be able to power up to 48 volt appliances.

The eight-panel series / parallel arrangement helps to add some balance to your solar system by bringing the volts and amps up to a good level while producing enough power for some moderate energy flexibility and freedom.

16 Panel Solar System Wired in Series & Parallel

The next solar power wiring diagram (arrangement) we’ll look at consists of sixteen solar panels and a battery bank with sixteen batteries in it.

With sixteen panels we have enough of them to arrange them using a combination of series and parallel wiring. We do this because it provides a better balance of volts and amps, instead of tipping the scales only to one side (like with just straight series or straight parallel wiring).

Here is an example of sixteen panels wired in a combination of series and parallel. If you’re going to be using sixteen solar panels/batteries in your system, you can follow the diagram below for a good balance of volts, amps and watts.

With the series / parallel arrangement (in the solar panel wiring diagram above), you can power 48 volt appliances, while charging your batteries faster (14 amps) thus storing more energy per available daylight hours, plus you get 420 amp hours of storage capacity. This is a great power reserve.

Series / Parallel Wiring – Sixteen Panel Solar System

Watts – Since we connected four groups of four panels together in series and parallel, this solar system will output 1008w of power per hour maximum (under optimal sunlight conditions). This is a great amount of power.

Battery – With four groups of four panels and batteries wired in series and parallel, your battery capacity is at 420 amp hours – so your battery can store/spend 420 amps total in the period of one hour. This is a great storage capacity.

Amps – With four groups of four panels/batteries wired in series and in parallel, your amps are at 14 amps which means you’ll be able to charge your battery bank faster and take better advantage of available daylight hours.

Volts – With four groups of four panels/batteries wired in series and in parallel, your panels’ volts are at 72 volts and your battery bank’s volts are at 48 volts which means you’ll be able to power up to 48 volt appliances.

This 16-panel series / parallel arrangement adds some balance to your solar system by bringing the volts and amps up to an acceptable level while providing enough power, charge speed, and storage capacity to handle most energy needs. You can now begin to enjoy some real energy independence.

But what if you want to power 120 volt appliances? Then you’ll need to add some stress to your 16 panel/battery solar system by wiring it only in series.

16 Panel Solar System Wired in Series

Now we’ll look at the same 16-panel solar arrangement as above, except we will wire the panels and batteries together only in series.

Although this system is not necessarily one that many would use (most would likely prefer the previous more balanced system because more balance extends battery life), the main reason for somebody choosing this arrangement would be to increase the volts high enough to power 120 volt appliances. Of course, you will be sacrificing amps (charging speed), and amp hours (storage capacity), but if powering up to 120 volt appliances is what you want, you will accomplish this.

If you’re going to be using sixteen solar panels/batteries in your system, it’s better to use the more balanced previous example, but if you absolutely need to power 120 volt appliances on a tight budget, this is how to do it.

Although the solar arrangement in the solar panel wiring diagram above isn’t the best for the long-term life of your battery because there is more stress on the system, it does provide a way to reach the capability of a bigger system without having to add more panels/batteries.

With the series arrangement above, you can now power 120 volt appliances, but you’ll charge your batteries slower (3.5 amps) thus store less energy per available daylight hours, plus you only get 105 amp hours of storage capacity.

Solar Panel Wiring Usage and Limitations

Series Wiring – Sixteen Panel Solar System

Watts – Since we connected 16 panels together in series, this solar system will output 1008w of power per hour maximum (under optimal sunlight conditions). This is the same wattage as the previous 16-panel system and thus has a great amount of power.

Battery – With sixteen panels/batteries wired in series, your battery capacity stays at 105 amp hours – so your battery can store/spend 105 amps total in the period of one hour. This is a low storage capacity.

Amps – With sixteen panels/batteries wired in series, your amps remain at 3.5 amps which means slower charging speeds and you won’t be able to take full advantage of available daylight hours.

Volts – With sixteen panels/batteries wired in series, your panels’ volts increase to 288 volts and your battery bank’s volts go to 192 volts which means you’ll be able to power up to 120 volt appliances.

While this 16-panel series arrangement helps to tilt the scales in the voltage favor, it also decreases some other very important factors that you may not want to give up. 

32 Panel Solar System Wired in Series & Parallel 

The next solar power wiring diagram (arrangement) we’ll look at consists of 32 solar panels and a battery bank with 32 batteries in it (using 4 groups of 8 panels/batteries).

Now that we have more panels to work with, we can arrange our solar panels/batteries using a combination of series and parallel wiring. But that’s not all, we can now try grouping them differently, so we’ll start by using four groups of eight. This arrangement will provide a better balance of volts and amps, instead of tipping the scales only to one side (like with just straight series or straight parallel wiring).

With the series/parallel arrangement in the solar panel wiring diagram above, you can power a 48 volt appliance, while charging your batteries faster (14 amps) thus producing/storing more energy per available daylight hours, and you get 420 amp hours of storage capacity which is great.

Solar Panel Wiring Usage and Limitations

Series / Parallel Wiring – 32 Panel Solar System (4 groups of 8)

Watts – Since we connected 32 panels together in series and parallel, this solar system will output 2016w of power per hour maximum (under optimal sunlight conditions). This is a pretty good amount of power and should be able to meet most of your energy needs.

Battery – With four groups of eight panels and batteries wired in series and parallel, your battery capacity is at 420 amp hours – so your battery can store/spend 420 amps total in the period of one hour. This is a great storage capacity.

Amps – With four groups of eight panels/batteries wired in series and in parallel, your amps are at 14 amps which means you’ll be able to charge your battery bank faster and take better advantage of available daylight hours.

Volts – With four groups of eight panels/batteries wired in series and in parallel, your panels’ volts are at 144 volts and your battery bank’s volts are at 96 volts which means you’ll be able to power up to 48 volt appliances.

This thirty two panel series/parallel arrangement adds some balance to a bigger sized solar system by bringing the watts and amps up to a great level which means you get great power and faster charging. The only drawback is that you can’t power 120 volt appliances. If this is important to you, you’ll have to use the next arrangement.

The next solar power wiring diagram (arrangement) we’ll look at consists of thirty two solar panels and a battery bank with 32 batteries in it.

This time we’ll be wiring our panels/batteries together in series and parallel using two groups of sixteen. We do this to raise the volts, this way we can power 120 volt appliances. Unfortunately, this will reduce our charging speed (amps) and storage capacity (amp hours).

Here is an example of 32 panels wired in series. If you’re going to be using 32 solar panels/batteries in your system, it’s better to use the more balanced previous example, but if you absolutely need to power 120 volt appliances without adding more panels/batteries, this is how to do it.

With the series / parallel arrangement in the solar panel wiring diagram above, you can now power a 120 volt appliance, while charging your batteries at an acceptable speed (7 amps) thus storing a pretty good amount of energy per available daylight hours, and you get 210 amp hours of storage capacity which is acceptable.

Series / Parallel Wiring – 32 Panel Solar System Usage and Limitations

Watts – Since we connected 32 panels together in series and parallel, this solar system will output 2016w of power per hour maximum (under optimal sunlight conditions). This is a pretty good amount of power and should be able to meet most of your energy needs.

Battery – With two groups of 16 panels and batteries wired in series and parallel, your battery capacity is at 210 amp hours – so your battery can store/spend 210 amps total in the period of one hour. This is an acceptable storage capacity.

Amps – With two groups of 16panels / batteries wired in series and in parallel, your amps are at 7 amps which means you’ll be able to charge your battery bank fast and take good advantage of available daylight hours.

Volts – With two groups of 16 panels/batteries wired in series and in parallel, your panels’ volts are at 288 volts and your battery bank’s volts are at 192 volts which means you’ll be able to power up to 120 volt appliances.

While this 32 panel (2 groups of 16) series / parallel arrangement helps to tilt the scales in the voltage favor, it also decreases some other factors. However, since we have a lot of panels to work with, the sacrifice is not that drastic.

As a result, you get great power, pretty good charge speed, and acceptable storage capacity, along with some true measure of real energy independence. Now that wasn’t that hard, what is?

Remember, if you use bigger solar cells to build your solar panels you can effectively raise most of the above values drastically and thus won’t require such a big solar energy system to meet your specific power needs. The bigger your solar panels’ output, the less of them you have to join together.

Here is a quick reference chart of all of the above info:

Solar Panel Wiring (Quick Reference Chart)