Choosing renewable energy is a noble action. It helps you to reduce your carbon footprint from the emission from diesel generators. A good battery is the backbone of a solar system. The best batteries for solar power storage allow you to harness and store the power coming from your panels. Consequently, when there is a power outage or the sun stops shining, the inverter draws the stored power from the battery for use. However, since there are different types of batteries, choosing the right one can be tricky. 

You need to consider several factors when choosing a solar battery. Most importantly, the battery of your choice needs to match your energy need. Since batteries provide backup power, you will need a battery that can store enough energy to power all your appliances during an outage from the utility grid. Our goal is to present you with options that will make it easier for you to choose the best off-grid battery. 

How do solar batteries work?

How solar panels work (Photo credit: Energis)

The working principle of a solar battery is quite simple. As the sun shines on your solar panels during the day, they produce electricity. The excess electricity is stored in the battery with the help of a built-in inverter. Once your battery is full, any further energy generated will go back to the grid. At night, you can draw power from your battery instead of the grid thus cutting back on utility bills. You will only start drawing power from the grid once your battery is depleted. 

However, it is important to mention that batteries can also be used without solar panels. This is because the batteries can be charged with electricity from the grid. This is useful in small-scale energy storage to provide backup instead of relying on a diesel backup generator. 

Review of the Best Batteries for Solar Panels

Those going off-grid usually rely on solar system batteries to store enough energy for use at night. However, those connected to the grid can also use it to cushion the effect of shortages. Without a doubt, owning renewable energy batteries is a great long-term investment. Whether you are shopping for a battery for your RV, cabin, or home, there is always a great option for you. We have done the bulk of the work so that you don’t have to go through the stress anymore. Without further chitchat, here is our list. 

ECO-WORTHY Lithium Iron Phosphate Battery – Best overall

Key features

  • Built-in Battery Management System
  • 3000+ life cycles
  • Amperage: 30Ah
  • Battery type: Lithium-ion (LiFePO4)
  • Weight: 7.2 pounds

It is not a secret that lithium-ion batteries are the best type of batteries. They hold more charge than lead-acid batteries while maintaining a smaller weight. However, ECO-WORTHY Lithium-ion battery is a notable investment for many reasons. Firstly, it has an inbuilt battery management system that protects the battery from overcharging, overheating, deep discharge overload, and short circuit. Unlike lead-acid batteries with about 300 to 400 cycles, this one boasts of over 3,000 cycles. Also, they are still able to maintain up to 80% capacity after 3,000 deep cycles. 

Interestingly, these batteries are compact and weigh just 7.2 pounds which means they can be your outdoor camping companion. Also, you can chain 4 of these batteries together in series or connect an unlimited amount in parallel. You can charge them using a solar panel or your utility grid. ECO-WORTHY Lithium-ion battery has high efficiency and can provide up to 95% of their rated capacity. This is in contrast to lead-acid batteries which usually cap at 50%. 

Since there are no fluids inside, it gives you some mounting flexibility. Also, due to its compact nature, it has varied applications. This includes a jump-starter battery, vehicle starter battery, and operating marine tools. However, this battery has its little flaws. The majority of the complaints about this product is that it delivers far less than the rated capacity. Also, considering the capacity, the price seems to be on the high side. Nevertheless, it is really hard not to love it. 

Pros

  • In-built battery management system extends battery life
  • Compact and lightweight makes it suitable for diverse application
  • Supports chaining
  • Over 3000 charge cycles
  • Lifespan is up to 10 years

Cons

  • Delivers less capacity than advertised
  • No warranty
  • Slightly expensive

Renogy Deep Cycle AGM Battery – Best AGM battery

Key features

  • High discharge current
  • Less than 3% self-discharge rate
  • Wide operation temperature range
  • Amperage: 100Ah
  • Battery type: Lead-acid, AGM
  • Weight: 63.9 pounds

Arguably the most important feature of the Renogy Deep Cycle AGM battery is the wide operating temperature. You will only get maximum performance off a battery under certain temperature ranges. For example, some batteries will stop performing properly at low temperatures. However, the improved electrolyte formula of this battery ensures stable capacity and discharge performance at below 0 degrees. It is made of high purity materials that reduce the self-discharge rate below 3%. This is 5 times lower than what you will get with flooded batteries.

Interestingly, Renogy Deep Cycle AGM battery is maintenance-free. It is made with thick absorbent glass mat (AGM) separators and advanced valve-regulated technology. The purpose of this is to prevent acid leakage and lower the need for frequent maintenance. This is one of the best solar system batteries for homes because it makes use of proprietary quinary alloy plates and specially treated plate grids that enable high discharge currents of up to 10 times the battery rating. What this means is that you can draw more power from the battery to run your appliances. 

On the downside, since this battery has liquid inside, you need to install it upright. In other words, this erases your installation flexibility. Also, this product is more expensive than some of the competing brands. Also, poor customer support seems to be one of the greatest setbacks with Renogy. Another thing you should know is that the case becomes brittle when exposed to direct sunlight. If these are not deal breakers for you, this is one of the best solar system batteries. 

Pros

  • Works in extremely low temperatures
  • Self-discharge rate is less than 3%
  • Protects against battery leaks
  • Allows you to draw more power than rated

Cons

  • Poor customer support
  • Extremely heavy
  • Almost limited to upright installation

ExpertPower Deep Cycle Battery – Best lead acid battery for solar

Key features

  • Absorbent Glass Mat (AGM)
  • Amperage: 33Ah
  • Battery type: sealed lead-acid (SLA)
  • Weight: 22.2 pounds

If you are looking for a small lead-acid PV battery storage, ExpertPower Deep Cycle Battery will easily catch your attention for several reasons. Firstly, it is highly affordable and gives great value for money. Due to its smaller size, compact nature, and lighter weight, you can take it for an outdoor camping experience without adding overwhelmingly to the bulk of your load.   

Another cool feature that comes with this battery is the absorbent glass mat technology. This technology makes it possible to use this battery within a wide temperature range. The manufacturer makes a bold claim that this battery is made with the highest quality material. For example, the case is made of non-conductive ABS plastic. This material has a strong resistance to vibration, shock, heat, and chemicals. In other words, these battery is built to last. 

The biggest drawback to using this product is a low capacity. Using it for a motorhome, for example, will leave you running out of power most of the time. Also, it doesn’t have enough power to run energy-intensive appliances like a refrigerator or an air conditioning unit. The durability is highly questionable. You will be fortunate to use it for over a year. Nevertheless, for a small PV battery storage system, it will make a good fit. 

Pros

  • Highly affordable
  • Compact and moderate weight allows flexible use
  • ABS plastic case offers shock and numerous protection
  • AGM makes it possible to use in a wide temperature range

Cons

  • Low amperage limits use
  • Durability is questionable

Weize Deep Cycle AGM Battery – Best battery for camping

Key features

  • Absorbent Glass Mat (AGM)
  • 1-year warranty
  • Amperage: 100Ah
  • Battery type: Sealed Lead Acid (SLA)
  • Weight: 57 pounds

The demand for Weize Deep Cycle AGM Battery is high—and it is easy to understand why. It makes use of a state-of-the-art, heavy-duty, calcium-alloy grid that provides exceptional performance and service life in both cyclic and float applications. Like most advanced sealed lead-acid batteries, this unit comes with absorbent glass mat (AGM) technology that encloses the indoor environment and gives it a broad operating temperature. 

Due to its compact nature, it has multiple applications including trolling motor, RV, travel trailer, boats, and so on. If you purchase this battery, you will get a few accompanying accessories including washers for both poles, bolts, and nuts. It also comes with protective caps for the poles. This helps to prevent electrocution accidents. The price point is another talking point. If you are swayed by a moderate price, this unit will be hard to resist. 

Like every electronics out there, Weize Deep Cycle AGM Battery has its cons too. When they don’t come damaged or in a bad pack, you will have to deal with a lower amperage than rated. A large number of reviewers complain that this is a 50Ah battery and not 100Ah as advertised. Others complain that it either fails to charge or doesn’t charge fully. Well, sometimes negative reviews result from not following manufacturer instructions. Let’s hope this is the case here. 

Pros

  • Comes with a 1-year warranty
  • AGM technology ensures broad operating temperature 
  • Suitable for a wide variety of use
  • Moderate pricing

Cons

  • Multiple complaints about charging capacity
  • Durability is questionable

Universal Power Deep Cycle VRLA Battery – Best battery for solar storage

Key features

  • Absorbent Glass Mat (AGM)
  • 1-year warranty
  • Amperage: 100Ah
  • Battery type: Sealed Lead Acid (SLA)
  • Weight: 63.93 pounds

Most sealed lead acid battery manufacturers will tell you to mount the product standing straight. However, Universal Power Deep Cycle VRLA battery allows you to mount it in any position. This is definitely a win for those hunting for mounting flexibility. Another important inclusion to this unit is the hard shell which is resistant to vibration and shock. This feature helps to prolong the lifespan of the battery.

Like all other SLA batteries with AGM technology, this unit performs well in hot and cold temperatures. Also, having a maintenance-free, spill-proof battery is always a great relief. One of the things to bear in mind is that for most SLA batteries you can only draw about half the energy rating. Perhaps, this is a means used by the solar regulator to prolong the life of the battery.

Although Universal Power Deep Cycle VRLA battery has a great price compared to other competing brands, it falls short in several ways. At 60 pounds, it is quite heavy and this can limit its use flexibility. One of the biggest setbacks with this unit is durability. It seems not to last very long. The problem usually starts with the battery refusing to hold a charge. Sadly, customer support is poor and you will have to deal with any issues yourself.

Pros

  • AGM technology allows use in broad temperatures
  • Offers 1-year manufacturer warranty
  • Flexible installation in any position
  • Its hard shell is shock and vibration resistant

Cons

  • Extremely heavy
  • Durability is questionable
  • Poor customer support

WindyNation AGM Deep Cycle Lead Acid Battery – Best 12v deep cycle battery for solar

Key features

  • Absorbent Glass Mat (AGM)
  • 1-year warranty
  • Amperage: 100Ah
  • Battery type: Sealed Lead Acid (SLA)
  • Weight: 71 pounds

When hunting for 12v deep cycle battery for solar, WindyNation lead-acid battery will easily grab your attention. It contains heavy-duty plates for deep, repetitive discharges. Thus, you can use it for all types of off-grid systems. Lower-quality batteries often make use of recycled lead but this unit is made with 99% pure virgin lead which allows for an extremely low discharge rate without causing any damage to your battery. Also, this ensures maximum power storage. 

At 25 degrees Celsius, this battery should last 10 to 12 years. The non-spillable design makes it compatible with locations where regulations mandate the use of such batteries like in healthcare facilities, airports, educational institutions, and so on. This battery is suitable for applications where the battery will be discharged and recharged thousands of times. Another interesting feature is the negative and positive terminal protectors that come with this product. 

WindyNation lead-acid battery is only a small fraction costlier than other top competing brands. In all sincerity, this can be ignored. However, some customers complain that the battery either failed to work on arrival or lasted only a short time. Although WindyNation offers one year warranty on this product, shipping back a used battery is often impossible because it is considered a potential fire hazard. It is something you need to ponder.

Pros

  • Made with over 99% pure lead
  • The non-spill design ensures broad application
  • Holds maximum power and recharges faster
  • Comes with terminal protectors
  • One year manufacturer warranty

Cons

  • Slightly costlier
  • Durability is about a year
  • Extremely heavy

Renogy Lithium Iron Phosphate Battery – Best off-grid battery

Key features

  • Less than 3% self-discharge
  • Integrated battery management system (BMS)
  • Over 2,000 charge cycles
  • Amperage: 170Ah
  • Battery type: Lithium-ion
  • Weight: 48.5 pounds

If you are planning to set up a large off-grid solar system, the Renogy Lithium Iron Phosphate battery is one of the best off-grid batteries for such a project. This lithium-ion battery has nearly four times the performance of lead-acid batteries with the added advantage of being lighter. Although Li-ion batteries are more expensive, it pays the price over time with extended lifespan. This unit boasts of over 2,000 cycles. This means that the service life is more than double that of traditional lead-acid batteries. 

Renogy Lithium Iron Phosphate battery has several security features including high and low voltage protection, high-temperature protection, over-high current protection, short circuit protection, and automatic equalization of battery pack capacity. This is thanks to the integrated battery management system. What is even more interesting is that this battery has good performance with a self-discharge rate of just about 3%. 

Generally, it is safer and more powerful than lead-acid batteries. However, both the battery and the manufacturer have their flaws. Firstly, Renogy seems to be getting everything wrong with their customer support. Thus, there are numerous complaints to that effect. Also, there have been a few instances where the battery failed after a short use or the BMS is not working. It is also important to mention that Renogy products are often overpriced and this battery is not an exception. Hopefully, you won’t have any reason to go through all the troubles. 

Pros

  • Built-in BMS protects battery life
  • Self-discharge rate over a month is less than 3%
  • Longer charge cycles
  • Lighter than lead acid of the same amperage but more powerful

Cons

  • Poor customer support
  • More expensive than competing brands

Mighty Max Battery – Best Budget

Key features

  • Absorbent Glass Mat (AGM)
  • 1-year warranty
  • 30-day refund 
  • Amperage: 35Ah
  • Battery type: Sealed Lead Acid (SLA)
  • Weight: 23.15 pounds

Most times the best product is simply the one that you can afford. This is why those on a low budget should consider the Mighty Max deep cycle AGM solar battery. Two of the top characteristics of this battery that make it a great asset include high discharge rate and wide operating temperatures. This is due to the incorporation of AGM technology. The technology also makes the battery spill-proof. The built-in handle looks nice too. 

Unlike most SLA solar system batteries with a strict mounting direction, the Mighty Max deep cycle AGM solar battery gives you the flexibility of mounting it in any position. Also, the encasing material is tough and resists shock and vibration which helps to prolong the life of the battery. It is easy to set up and wire to a solar array. One of the biggest advantages of using heavy-duty batteries is that they can power demanding appliances like a 12v air compressor. 

In addition to a 1-year warranty, the manufacturer is offering a 30-day refund. But, utilizing this policy is not as straightforward as it sounds. However, one of the biggest problems that some customers reported is that it doesn’t last long. Some said it start failing after 6 months. Also, since this is a low power battery, don’t expect to run heavy appliances off it. Nevertheless, when your budget is a huge obstacle, you can bank on this battery. 

Pros

  • Highly affordable
  • Come with a nice carrying handle
  • Offers 1-year manufacturer warranty with a 30-day refund
  • Mounting is possible in any position
  • Shock and vibration resistant

Cons

  • Durability is questionable
  • Run out of power in under 1 hour

Buying Guide for the Best Batteries for Solar Panel

Your power need and budget will likely determine the battery that you would buy. Without the best solar batteries, the entire aim of going off-grid will be defeated. This is because you won’t have any backup if there is a drop from the grid. While we have outlined the top batteries for solar systems, we will give you important tips that will help you to make a good decision—if you ever decide to do personal research. 

Battery type

When selecting a battery for your solar system, the first thing that you need to consider is the type of battery you want. There are three main types of solar system batteries namely; lithium-ion (Li-ion), sealed lead-acid batteries and flooded lead-acid batteries. Of all the types of batteries, the Li-ion battery is the most efficient. It delivers the most power while maintaining the lightest weight. However, Li-ion is also the most expensive of all the battery types. 

Battery capacity

The battery capacity is another important consideration when making a choice. The battery capacity should tally with your energy need. Long story short, the bigger the battery capacity, the more energy it can store. If you want a solar setup that can last you through the night, you need a battery with a huge capacity to store as much power as possible from your solar panels during the day. 

Charging time

While charging time depends on many factors including the amount of energy generated by your solar panels and the quality of your charge controller, some batteries tend to charge faster than others. Among all the types of batteries, gel batteries tend to charge the fastest while Li-ion batteries take a longer time to charge. The faster your battery charges, the sooner you can start using them—and cut back on utility supply. 

Lifespan

The lifespan of your battery is another important consideration. It is important to mention that batteries lose their ability to hold a charge as the days go by. Some batteries degrade faster than others. However, you can continue to use a battery until it can no longer hold a charge. 

Depth of discharge (DoD)

This refers to the amount of battery capacity that you can use before recharging. For example, if a 10kWh battery has a depth of discharge of 80%, you should recharge it each time you use 8kWh. The higher the depth of discharge, the more of the battery’s capacity you can use. 

Ease of installation

Some batteries are easier to install than others. For example, lead-acid batteries have limited installation flexibility. Most of them must be installed standing erect. This makes them unsuitable for use on some surfaces with limited spaces where the battery must be angled to fit. 

Price

A lead-acid battery is more suitable for those on a tight budget—but is less durable. Li-ion batteries often have over 3,000 charge cycles but are usually very expensive. Thanks to the large battery variation, there is something for everyone. 

Warranty

Deep cycle batteries are usually unpredictable. Even the manufacturers of the best batteries for solar panels often ship out defective products out of error. At other times, the batteries may fail to perform as they should. Purchasing a product that is backed by a warranty will save you potential headaches. 

What kind of batteries do you use for solar panels?

Types of solar panel batteries (Photo credit: Liter of Light USA)

Having a better knowledge of the different types of batteries will make it easier for you to make a choice. There are three broad classes of battery namely lithium-ion, flooded lead-acid, and sealed lead-acid batteries. 

Flooded lead-acid battery

This is one of the off-grid batteries. They are wet cells, meaning they contain fluid in them. Their biggest advantage is the lower upfront cost and the fact that they are 99% recyclable. These batteries are among the oldest. Their use dates back to 150 years. They have lower DoD and shorter lifespan compared to other battery types. 

Flooded lead-acid batteries often give off gas as a byproduct, hence the need for proper ventilation. They also require regular maintenance including making sure all the plates of every cell are submerged. For those that want to go totally off-grid and install numerous batteries for solar storage, lead-acid can be a great choice. 

Sealed lead-acid battery

These solar system batteries are a little modification of the lead-acid batteries. They are non-hazardous and spill-proof. There are two types of these batteries namely the gel and absorbent glass mat (AGM). One of the main advantages of this battery is that they don’t discharge as fast as lead-acid batteries if left idle for a long period. 

Sealed lead-acid batteries don’t require much maintenance. You don’t need to refill the battery with water like the flooded batteries. Therefore, they can be used in applications where flooded batteries are not allowed. Also, these batteries can be used in environments with slightly extreme temperatures. 

Lithium battery

This is one of the newest deep cycle battery entrants in the market. The technology became popular in the 1970s and was mainly used for electronic devices like smartphones and laptops. Today, they are more popular as renewable energy batteries. Their strongest advantage is their longer lifespan and higher efficiency. Also, they are safe and don’t give off gas like lead-acid. 

Frequently Asked Question

  • How much are batteries for solar panels?

 Depending on the type and size of the battery, the price can range from $60 to over $1,000. These prices are for the batteries and don’t include installation or additional equipment. 

  • Can I use any battery for solar panel? 

Every battery was made with a purpose in mind. For solar systems, lead-acid and lithium-ion deep cycle batteries are mostly used. 

  • How do I choose a solar panel battery?

Most solar panel systems make use of 12v deep cycle batteries. For larger solar systems, you may need to pair two or more batteries to achieve your energy storage need. It is important to pair a 12v battery with a 12v battery from the same manufacturer. 

  • Is it worth getting batteries for solar?

There is a huge benefit of having batteries for your solar system. It allows you to save excess energy from the sun during the day so that you can use them at night when the sun is no longer shining. It also helps you to cut down on your utility bill due to a reduction in the use of power from the grid. 

  • How many batteries can a 100 watts solar panel charge?

On an average sunny day (all things being equal) a 100 watts solar panel will produce 30Ah of electricity. Therefore to fully charge a 100Ah battery, you will need three 100 watts solar panels. 

Conclusion

Owning the best batteries is paramount to maximize the benefits of a solar power system. If you are linked to a grid, not owning a battery simply means you don’t have any backup power. Once there is a cut from the grid, you will be affected. On the other hand, a solar system will not work at all without a battery if you are off-grid. Interestingly, by stringing the right amount of batteries and solar panels, a house can actually run on solar power alone. That is zero recurring expenditure on utility. Think about it.

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