DIY Solar Battery Backup – What You Need and Mistakes to Avoid (2023)

DIY Solar Battery Backup – What You Need and Mistakes to Avoid (1)

Table of Contents

  • DIY Solar Battery Backup – What You Need and Mistakes to Avoid
  • The Benefits of Adding a Solar Battery Backup to Your Solar Power System
  • Hybrid Solar Power Systems:
  • What Do You Need to Build a Solar Power System with a Battery Backup?
  • How to Build a DIY Solar Battery Storage
  • Mistakes to Avoid
  • Final Words

DIY Solar Battery Backup – What You Need and Mistakes to Avoid

While it goes without saying that you will need a high-capacity battery bank if you are planning to build an off-grid solar power system, many people forget that you can also add a battery backup to a grid-tied system.

A solar battery backup can act as an emergency power supply in the event that the grid fails, or it can simply allow you to access free and environmentally-friendly electricity during peak hours when electricity prices are raised.

All you need to do to create your own DIY solar battery backup is invest in one or more deep cycle solar batteries, as well as the other necessary components needed to allow those batteries to work efficiently.

If you are in an area that has an unreliable electrical grid, or you live somewhere that is susceptible to severe weather conditions, investing in a solar battery backup is one of the best decisions you can make. To help you build your own DIY solar battery backup, we are going to go over everything you will need, as well as list some common mistakes that you should try to avoid.

DIY Solar Battery Backup – What You Need and Mistakes to Avoid (2)

The Benefits of Adding a Solar Battery Backup to Your Solar Power System

Adding a solar battery backup to your existing system will offer plenty of financial benefits. When your solar panels are overproducing, or you have excess solar electricity, you can store it in batteries for emergency situations and for use when net metering prices are at their highest.

Unless you are running a fully off-grid system, where the electricity stored in your solar batteries is the only power you have access to, adding a solar battery backup to a grid-tied solar power system creates what is often known as a hybrid system.

Hybrid Solar Power Systems:

Essentially, a hybrid solar power system is a combination of a grid-tied system and an off-grid system.

(Video) Top 10 Beginner Mistakes When Building a DIY Solar System

You get the financial benefits and the flexibility you get with a grid-tied system, but also the added benefits of a reliable power storage system that will allow you to access solar electricity at your convenience.

Hybrid systems are connected to the grid, meaning the owner can choose to feed solar electricity into the grid for cash rebates and monthly discounts from the local utility company, but they also store some of the electricity in one or more solar batteries, for emergencies and use during peak hours.

For the average homeowner, it makes sense to maintain a connection with a local utility company, as satisfying all of your electricity needs with only solar power can be difficult, unless you own a massive plot of land that receives plenty of direct sunlight. Hybrid systems allow you to keep this connection, so you can feed into and draw from the grid, but you also get the benefits of a solar battery backup.

These solar-plus-storage systems allow you to get the maximum financial benefit from solar power by avoiding peak electricity prices.

DIY Solar Battery Backup – What You Need and Mistakes to Avoid (3)

What Do You Need to Build a Solar Power System with a Battery Backup?

Given that grid-tied systems are often the most cost-efficient types of solar power systems to install, it is no wonder that they are incredibly popular. If you currently run a grid-tied power system, you will be happy to learn that it is actually quite easy and affordable to retrofit your existing system with a solar battery backup.

If you do not currently have a solar power system, but you are looking to invest in one, we will explain how you can easily add a solar battery backup to any system you end up building.

The basic components you will need in order to equip your solar power system with a battery bank are as follows:

  • An appropriate charge controller
  • A solar power inverter
  • One or more deep cycle solar batteries
  • The necessary cables, mounts, and connectors

The charge controller plays a vital role in any solar storage system. While the main purpose of a charge controller is to regulate the flow of electricity from the solar panels to the battery bank and prevent overcharging issues, the more advanced charge controllers also prevent battery drain, which occurs when electricity flows from the battery to the solar panels when they are no longer producing electricity.

The power inverter, which you will be familiar with if you are currently operating a grid-tied system, converts the DC power your solar panels generate into AC power, which is required to power your electronic devices and appliances. Using a power inverter with a solar battery backup ensures that the electricity stored within your batteries can actually be used for charging and running your electronic devices and appliances.

(Video) Top 7 Mistakes Newbies Make Going Solar - Avoid These For Effective Power Harvesting From The Sun

Deep cycle batteries are specifically designed to handle the repeated charging and discharging that occurs when you are using solar power. Where other high-capacity batteries, like those you would find in your car, are designed to provide a quick burst of power, deep cycle solar batteries are meant to be used as a power bank that can supply a steady flow of electricity to any electronic device or appliance that is drawing power from them.

How to Build a DIY Solar Battery Storage

Calculate Your Load and Select Your Batteries:

Now that you know what you will need, you can actually assemble and install your DIY solar battery storage. The first step is calculating the amount of electricity you will need to store. By calculating your load, you will be able to figure out how many batteries your storage system will require.

Use our Solar Watt Hour Load Calculator to determine your storage needs. From there, select the number and type of batteries you will need to satisfy your load requirements.

You will be able to find exactly what you need by browsing our Deep Cycle Solar Battery Collection, which contains 12V, 24V, and 48V solar batteries from some of the most reputable brands in the industry

DIY Solar Battery Backup – What You Need and Mistakes to Avoid (4)

If you are looking to build a budget-friendly solar battery storage bank, we recommend taking a look at the BattleBorn 100Ah 12V Deep Cycle Battery. This lithium-ion solar battery can be 100% discharged, charges quickly and efficiently, features a built-in battery management system, and it is available at a low price. Best of all, it can be stacked, meaning you can connect numerous batteries to build a high-capacity battery bank for your solar power system.

Buy here

Choose a Charge Controller:

The charge controller will regulate the voltage and current coming from your solar panels, so it is necessary to choose one that allows your solar power system to operate optimally at all times.


DIY Solar Battery Backup – What You Need and Mistakes to Avoid (5)

MPPT charge controllers tend to have the greatest level of efficiency, but they are also more expensive than the less complicated PWM options. Find the perfect charge controller for your particular battery bank and solar panel combination by shopping our Charge Controller Collection. We carry a wide range of both MPPT and PWM charge controllers with wide variety of different amp ratings.

Buy here

Select a Power Inverter:

You will want a power inverter that has a power rating that is equal or more than the total load in watts of your system. This will ensure your system runs efficiently and the power stored within your batteries will be the correct type of current for your needs.

You will be able to find a wide variety of solar power inverters, as well as useful information about selecting the right inverter voltage for your battery bank by browsing our Solar Power Inverter Collection.

Wire Everything Together:

The first component you are going to wire is the charge controller. Most charge controller instruction manuals will tell you to connect the device to the batteries first, as this will allow it to get calibrated to the correct voltage for your batteries. Once it is connected properly, your charge controller’s indicator light should activate and tell you the charge status of your batteries.

DIY Solar Battery Backup – What You Need and Mistakes to Avoid (6)

Now you can connect your solar panels to the charge controller. Again, follow the steps as outlined in the charge controller’s instruction manual. From there, you simply have to connect the system to your power inverter, which will ensure your batteries are storing AC power, rather than DC power.

(Video) Simple Tips To Help You Avoid Common Solar Power Mistakes.

Mistakes to Avoid

Some of the most common mistakes people make when introducing a DIY solar battery storage to their solar power system is forgetting to make sure that each of the components they have purchased are compatible and operate at the same voltage.

People will also underestimate their actual power needs, which is why it is so important to do a proper load calculation before you select the number and type of deep cycle batteries you are going to purchase.

Some people will also purchase a low-quality and low voltage charge controller in an effort to save money. While these low voltage PWM charge controllers are cheaper, many of the higher voltage MPPT charge controllers are multi-voltage capable, meaning they can handle any voltage and can adapt with your system as you expand it.

It is also important to read your instruction manuals and seek out help when you are unsure of what to do. Rather than risk damaging your solar equipment, do your research. While you can certainly install a solar battery backup on your own, you should always take the time to make sure you know what you are doing.

Final Words

Building a DIY solar battery backup does not have to be complicated or overly expensive. By selecting the correct components for your needs and wiring everything together with care, you can quickly and easily enjoy the freedom of accessing solar power at your convenience.

For more information about choosing the correct solar power storage equipment, read our Best Battery Bank Guide, which will tell you everything you need to know about solar batteries and solar generators.

If you have any questions about building a solar battery backup, or any other questions relating to solar power, please do not hesitate to contact us. We are always here to help!

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What are 3 drawbacks to storing solar energy in batteries? ›

Disadvantages of A Solar Battery
  • Energy Storage is Expensive. The cost of energy storage is quite high and can quite easily increase the cost of your solar PV system substantially. ...
  • Increased Complexity of Your Solar System. ...
  • Increased Maintenance For Your Solar. ...
  • Lifespan of Home Battery.
May 3, 2018

How do you prevent solar battery from overcharging? ›

Higher charging voltage from the solar panels leads to higher Ah being delivered to the battery and ultimately leading to overcharging. The easiest way to control over charging of the batteries is to control the output voltage of the solar panel. A hybrid inverter can do this.

How can I improve my solar battery backup? ›

8 Tips for Extending Battery life for your Solar Power System
  1. Rotate your Batteries. If you have a large bank of batteries, rotate the batteries within the bank periodically. ...
  2. Use large battery interconnect cables. ...
  3. Properly charge your battery. ...
  4. Allow gassing or boiling. ...
  5. Battery Equalization.
Feb 12, 2016

What can damage solar battery? ›

Heat is the enemy of batteries,” Rowe said. “While a battery in warmer temperatures can produce more energy in the short term, the degradation of the internal components is accelerated.” It is important to note that even short periods at high temperatures can have an impact on battery life, McDowall added.

What happens to solar power when batteries are full? ›

Should the battery bank become full, it will stop absorbing power from the solar system. The solar panels will continue to generate voltage, but that voltage will not be used or stored until there is available energy demand, or battery space.

What they don t tell you about solar panels? ›

Solar Panels Don't Require Maintenance

Despite what solar panel makers may tell you, maintenance of the panels is not a problem once you have them installed. Solar panel manufacturers try to get people to lease solar panels, insisting that then the homeowner won't have to worry about maintenance.

What is the main negative of solar energy? ›

High initial costs for material and installation and long ROI (however, with the reduction in the cost of solar over the last 10 years, solar is becoming more cost feasible every day) Needs lots of space as efficiency is not 100% yet. No solar power at night so there is a need for a large battery bank.

What is the biggest problem with solar? ›

What is the biggest problem with solar energy? Among the disadvantages of photovoltaic power generation, the one that stands out the most is its initial value. Despite paying off the investment in a few years, the value can still be high for some homeowners and even small businesses.

What causes solar batteries to drain quickly? ›

It may be that charging and discharging the batteries too quickly is a sign of inadequate battery sizing, improper IMEON settings, or the end of battery life.

Do solar batteries charge when turned off? ›

Switch off and leave to charge for 72 hours

Many solar powered lights will still charge if they are not turned on, and by turning them off you actually allow the battery to get a full charge over several days of sunlight.

What stops a battery from overcharging? ›

The right charger for your battery is crucial to prevent overcharging; the charger must match the battery in terms of output voltage and Ah rating. It's easier to avoid overcharging in lithium-ion batteries because they can receive a partial charge or be charged intermittently.

What makes a good solar battery? ›

When choosing a solar battery, the kWp rating indicates the highest amount of power it can output at its best performance: the higher the peak power output rating, the better the battery.

Can a solar battery be too big? ›

An oversized solar battery could also lead to chronic undercharging and poor performance and lifespan. Search tool allows you to specify exactly what elements of a home should be powered by the battery.

How do you keep solar batteries charged at night? ›

Use mirrors. At different times of the day, there maybe shadows cast on your solar panels that mean they are charging using indirect light and not direct. You can use mirrors to reflect sunlight directly onto your panels during these known periods and get more charge than you would otherwise.

What causes solar batteries to overheat? ›

Poor airflow or lack of air conditioning can lead to the buildup of heat in the cells. Batteries regularly subjected to ambient temperatures above 77° F (25° C) are more prone to thermal runaways.

Can you overcharge a solar battery? ›

As a general rule a solar panel can overcharge a battery. The charge rate depends on the solar panel voltage, the output current and the battery voltage. Overcharging is eliminated by using a solar charge controller.

What is the safest solar battery? ›

Solar battery safety

The safest one in existence today is lithium iron phosphate battery technology, or LFP. These are highly stable and have no chance of overheating. They also run very cool which means they can be placed inside your home, if desired, and won't require extra ventilation or cooling.

Can I run my home off solar battery if the power goes down? ›

This means you don't have to decide upfront which devices you want in your essential load. Batteries powered by solar panels can keep your home running even when an outage lasts for several days.

Is it better to have more solar panels or more batteries? ›

More panels means greater square footage of solar cells exposed to the sun, resulting in higher efficiency and longer runs times into the earlier morning and later evening when very little sun is available. If you're needing just an hour or two of longer run time, try adding another line of panels.

Can solar panels drain batteries at night? ›

A very common question asked by many. The answer is yes. Solar panels will discharge at night if your solar panel doesn't have a diode or it is broken. In fact not only does it happen at night, but it also happens when the panel doesn't get sunlight.

What are 3 negatives about solar energy? ›

Solar isn't perfect – here are some disadvantages of solar energy to keep in mind when considering installing solar panels: Solar doesn't work for every roof type. Solar isn't ideal if you're about to move. Low electricity costs = low savings.

Why do people not want solar panels? ›

The truth is, not everyone qualifies for solar. For example, if you don't have enough unshaded roof space or property to generate enough power to offset your electricity bills, then going solar wouldn't be a smart thing to do.

Why solar panels are not popular? ›

Essentially, the two biggest problems are cost and infrastructure. Fossil fuels are cheap, reliable, and familiar, because they've been around for longer. Switching to solar can intimidate people, because the upfront cost is often high, even though it's lower than it's ever been before.

Do solar panels cause roof leaks? ›

In virtually all cases, the answer is no. Roof leaks after solar panels are extremely rare. When roof leaking after the solar panels are fitted does occur, however, it usually becomes evident very quickly after the installation process is finished.

Do solar panels work on cloudy days? ›

Photovoltaic panels can use direct or indirect sunlight to generate power, though they are most effective in direct sunlight. Solar panels will still work even when the light is reflected or partially blocked by clouds.

Do solar panels make your house hotter? ›

According to a study conducted by researchers at UC San Diego Jacobs School of Engineering, solar panels reduced the amount of heat reaching the roof by an incredible 38%, keeping a building's roof 5 degrees cooler than portions of a roof exposed to sunlight directly.

What toxic waste comes from solar panels? ›

Solar panel waste can include heavy metals such as silver, lead, arsenic and cadmium that – at certain levels – may be classified as hazardous waste.

Why are my solar panels not producing enough power? ›

If the PV cells become obstructed, they won't turn sunlight into energy as efficiently as they should. While not all that common, a buildup of debris, such as leaves, twigs, branches, bird droppings, and dirt might be causing your panels to underperform.

What drains solar battery? ›

Whenever a load is connected to the battery, it draws current from the battery, resulting in battery discharge. Battery discharge could be understood to be a phenomenon in which the battery gets depleted of its charge. Greater the current drawn by the load, faster the battery discharges.

How many amps is 100 watts of solar? ›

When a 12V solar panel is rated at 100W, that is an instantaneous rating, if all of the test conditions are met, when you measure the output, the voltage will be about 18 volts and the current will be 5.55 amps. Since Watts equals volts times amps, 18 volts x 5.55 amps = 100 Watts.

What causes battery drain overnight? ›

What may drain a car battery when it's off are things such as interior lights, door lights, or even bad relays. While your engine runs, the alternator recharges the battery — which is why you typically don't have to worry about the battery dying while you're blasting the radio on your drive to work!

Can solar batteries charge without direct sunlight? ›

The short answer is – yes! Although direct sunlight is key to charging solar panels, they continue to charge even on cloudy, overcast days. Sol's innovative lighting systems and products, for example, are designed to work for at least four days with no direct sunlight!

Do solar batteries charge in winter? ›

As long as your solar panels do not remain covered in snow for an extended period of time, solar panels can still generate enough power to run your household and charge your batteries. Whilst it is true that heavy snow fall can reduce sunlight penetration, your panels will produce more electricity than you might think.

How do you charge a solar battery without sunlight? ›

Solar panels can charge with other forms of visible light besides sunlight. Artificial lights such as incandescent fluorescent bulbs can be used to charge solar cells, provided the light is strong enough.

Is it OK to leave a lithium-ion battery on the charger overnight? ›

Most power banks use lithium-ion batteries, which are safe to leave plugged in and charging overnight.

What can I turn off to make my battery last longer? ›

Use Wi-Fi instead of mobile data. Turn off Bluetooth. Turn off Location access. Some apps and features won't work when Location is off.
To save battery life, try not to:
  1. Tether your phone (hotspots).
  2. Use GPS for long periods.
  3. Stream videos or music.
  4. Make phone calls on the move, like in a car.

How do I know if my battery is overcharging? ›

Use A Multimeter

When the vehicle is started, without the introduction of a load (the lights or air conditioner), the volts will usually rise to an average of 14 volts. If the multimeter reads at more than 14.8 volts, then this can be considered as overcharging.

What is best battery voltage for solar system? ›

If your solar array capacity is:
  • < 1000W then 12V is Good.
  • > 1000W and < 2000W then 24V is Better.
  • > 2000W then 48V is Best.
Mar 2, 2022

How many batteries do I need to run a solar panel? ›

If you want to save the most money possible, you'll need enough battery storage to cover your energy usage when your solar panels aren't producing – somewhere around 2-3 batteries. If you want to keep the power on when the grid is down, you'll usually just need one solar battery.

How many amps can a solar battery produce? ›

Solar Batteries come in all shapes and sizes. The most common measurement of battery storage capacity is the Amp-Hour or Ah. The size of solar batteries can range from less than 100 Ah, to more than 1,000 amp-hours in single battery.

What are the best batteries for solar off grid? ›

Lead acid or gel type batteries may work if you're looking to test a solar setup short-term to see if it's a right fit for you. But when you consider efficiency, reliability and lifetime cost, it's clear that lithium comes out on top as the best contender among all off grid solar batteries.

What do you do with solar batteries in the winter? ›

Keeping the batteries in an insulated area ensures you maximize their performance, even if the temperatures outside are dropping. Even better, if the cold weather impacts the production of your solar panels, you can then rely on your stored power.

Do solar batteries need ventilation? ›

They need less ventilation than flooded batteries because they only discharge gas if overcharged. If you are installing batteries in an area with imperfect venting, AGM or gel batteries may be the safer way to go. This does not mean that no precautions should be taken.

How do I check the health of my solar battery? ›

The first way to do this is the easiest: first, charge the deep cycle batteries within your solar battery bank fully. Next, check the voltage of each battery using a multimeter and make a note of each level, then let them sit without a connection to any solar panel for a few days.

What are the disadvantages of battery storage? ›

Some of the disadvantages of battery stored energy systems include:
  • Shorter service life. While a flywheel storage device has around the same service life as the UPS, batteries generally need to be replaced several times over the same period.
  • Higher maintenance requirement.

What are the drawbacks of solar energy systems? ›

Pros and Cons of Solar Energy
Advantages of Solar EnergyDisadvantages of Solar Energy
Reduces Electricity BillsWeather Dependent
Diverse ApplicationsSolar Energy Storage is Expensive
Low Maintenance CostsUses a Lot of Space
Technology DevelopmentAssociated with Pollution
1 more row
Feb 14, 2023

What are three major problems with solar energy? ›

The cons are that it only produces energy when the sun is shining, needs a significant amount of land, and that certain solar technologies require rare materials.

Do solar batteries work in a blackout? ›

Is your solar battery blackout-proof? Forget candles. Solar batteries can keep the power running during a blackout.

Is it worth having a battery with solar panels? ›

Solar batteries can be a handy add on to your solar panel set-up. Whilst you can still make full use of your solar panels without a solar battery; the benefits of having solar batteries means you might rely less on the grid and be able to store and use the electricity that your house generates.

What happens to solar panels after 25 years? ›

The industry standard for the lifespan of solar panels is 25-30 years. However, a solar panel won't die after 25-30 years – rather, its power output will decrease a significant amount below what the manufacturer projected.

What are 4 main problems associated with installing solar in your home? ›

Nine Common Problems with Solar Panels
  • Delamination and internal corrosion. If moisture finds its way into the panel, it can cause internal corrosion. ...
  • Electrical issues. Faulty wiring prevents your solar panels from performing well. ...
  • Micro-cracks. ...
  • Hot spots. ...
  • PID effect. ...
  • Birds. ...
  • Snail trails. ...
  • Roof issues.
May 16, 2019

What are 10 disadvantages of solar energy? ›

10 Disadvatanges Of Solar Panels
  • High upfront cost. ...
  • The size of system is dependent on your available space. ...
  • Requires sunny weather to work best. ...
  • Manufacturing of solar panels can harm the environment. ...
  • Low energy conversion rate. ...
  • Cannot be used at night. ...
  • Solar panels are fixed at their installed location.


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(GreenMatch UK)
5. URGENT! Do Not Buy Solar! Do This Instead. Save $1,000's!!! Mango Power E Review
6. My 3 Biggest Regrets After 6 Years of Solar


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