Power

What are the Best Batteries for an Off Grid Solar System?

By Lee Stauss Updated on June 28, 2024

For energy storage, solar batteries make a smart investment. You won’t have the ability to store the energy generated by your system in a bank for later use. A battery bank is essential if you are tied to the grid. Without it, there will be no backup power in case the utility grid goes down. Your system won’t work if you live off the grid.

Battery power is essential to keep your system in good condition.

There are many factors that go into choosing the right solar panel battery. These include the battery’s power, capacity, efficiency, cost, and other considerations. Let’s take a look at how solar cells work and the various types of solar batteries. We also have recommendations for the best solar batteries in 2020.

How do solar batteries work?

You can store excess solar power instead of sending it back into the grid by installing a solar battery in your solar panel system. You can charge your battery with excess electricity from your panels if they produce more than you need.

If your solar panels don’t produce electricity, you can still draw on the stored energy whenever you need it. The electricity is only sent back to grid when your battery is full, or drawn from the grid when it is low.

What are the Different Types of Batteries?

Most batteries for energy storage are made from lead-acid and lithium-ion. Before you make your choice about the best solar battery, it is important to know the differences between deep cycle, sealed, flooded, and lithium batteries. These are the differences between lithium-ion and lead-acid batteries.

Flooded Lead Acid Batteries

Flooded lead-acid batteries (FLA) have been around for 150 years. They are one of the most popular batteries for off-grid solar systems. These batteries are cheap, 99% recyclable and easy to dispose of at the end.

These are the best solar batteries if you want an affordable option with the following hands-on monitoring.

Flooded lead-acid battery are built to handle daily charge cycling. They can produce gas byproducts, so it is important to ventilate them properly.
FLA batteries are great for those who like to get involved with the system. These batteries are the most economical, but they require some upkeep in order to function properly.
These batteries require regular maintenance. To function properly, the plates of each cell must be immersed in water. This is why “flooded” batteries are named. To keep the plates submerged, you will need to add water approximately every one to three months. It is a good idea to check them once per month.

Sealed Lead-Acid Battery

The sealed lead-acid batteries with these benefits are the best for solar panels if you are not able to do regular checks.

These batteries are non-hazardous and spill-proof. Two types of sealed lead-acid battery are available with similar characteristics: gel (absorbent glasses mat) and AGM (absorbent acid batteries).
Sealed batteries can be used as a self-contained unit. They can be used without the need for water refills like flooded batteries. They can be used in properties that are not occupied full-time like an off-grid vacation cottage that you only visit once or twice per year.
Sealed batteries can handle higher temperatures better. If they are left inactive for long periods, they won’t be able to self-discharge as quickly.

Lithium Batteries

Lithium batteries, a relatively new technology, first appeared on the market in 1970. These batteries are used in smartphones and laptops. However, they are becoming more popular in renewable energy. Although lithium batteries are more costly, there are many benefits that make up for the increased price.

Longer lifespan
Maintenance not required
Energy usage that is more efficient
Deeper discharges result in more storage capacity.
No off-gassing/ventilation

How do I compare solar batteries?

You should compare the different types of solar batteries to determine the best ones for your needs. These are the things you should be looking out for:

Capacity: This is the amount of electricity a solar battery has the potential to store. This power is measured by kilowatt hours (kWh).
Depth of discharge: This is the depth at which the battery’s capacity has been used. The DoD is a measure of how much you can get out of your battery’s capacity. The minimum depth of discharge should be 40% or more.
Round-trip Efficiency: The difference between the energy required to charge the device and the amount available for charging it is called round-trip efficiency. Higher round-trip efficiency is usually more economic. Round-trip efficiency should be around 80%.
Battery life and warranty: Because battery performance decreases over time, a warranty ensures that the battery performs well for years or even cycles. It also guarantees that the battery will retain a certain amount of capacity.

What are the best solar batteries for 2022?

What are the best solar batteries on the market today? Here are our top recommendations for the most effective solar batteries in 2022.

The best off-grid home battery: 48V lithium
Crown CR430 FLA is the best off-grid home battery
Fullriver DC400-6 AGM is the best off-grid option for vacation homes
Fullriver DC400-6AGM is the best battery backup for grid-tie system
The best battery for energy resale? 48V lithium
Best battery for mobile systems/Crown 6CRV220 SLA

How do I choose the best solar batteries?

How can you choose the right batteries for you? The right battery for you depends on your needs, budget, and expectations. The best battery for your project will depend on your personal situation. We have compiled a list of the top solar batteries:

Best overall Off-Grid Battery

A battery is essential if you live off-grid.

The Discover 48V Lithium lithium battery is our recommendation for the best off-grid home battery. If you want a long-lasting battery with the ability to be expanded at a reasonable price, this is it. These are the reasons to choose this battery:

Lithium batteries make a great storage choice. They are more durable than other types of batteries and can charge quicker. Because they can withstand deeper discharges, they require less capacity than a comparable lead-acid bank.
It is also easier to add more systems over time. Imagine that you want to add a well pump to your property. It can be hard, or even impossible to increase your lead-acid battery bank depending on how old they are and how wired. However, lithium batteries are able to expand their battery bank without difficulty. Each battery can be upgraded over time, as each one is independent and has its own Battery Management System (BMS).
Long-lasting lithium batteries can last for many years without needing to be recharged. This would cause damage to lead-acid batteries as they must be charged every day. They will become damaged after a few days without full charge.

The Best Off-Grid Battery for Homes

Are you looking for something more economical? Crown CR430 flooded-lead-acid batteries are the best value for off-grid systems. This option is recommended if:

The off-grid lifestyle is for you. The CR430 is a great option if you enjoy DIY projects and aren’t afraid to do minor maintenance on your battery bank.
This unit offers reliability and capacity at an affordable price. For the price, the 430 amp-hours of capacity is unbeatable. Crown is an American manufacturer that has been reliable (they appear on this list 4 times). CR430s can be built at Crown’s advanced manufacturing facility in Fremont, Ohio.

Best Off-Grid Battery for Vacation Homes

What happens if you own an off-grid vacation house that you don’t visit often? Because you will only be visiting the site a few times per year, you want a battery that is easy to maintain.

A sealed AGM battery in these situations is the best choice. We recommend the FullRiver DC400-6 415Ah FullRiver.

Because you don’t require year-round storage, the lower capacity is a good thing. We skipped the premium lithium option because it was too expensive for a system that is only used once a year.
These batteries are very affordable. These batteries are not expensive and you don’t need to invest a lot of money in a place where you won’t be spending much time.

The Best Battery for Grid-Tied Backup

A battery with a lot of storage capacity is not necessary if you have an emergency grid-tied system. We recommend the FullRiver DC400-6 battery with sealed AGM.

The battery should only be used when it is absolutely necessary. The battery won’t be used if your power goes off, which hopefully doesn’t happen more often than once per year.
Grid-tied batteries require low maintenance. A battery that does not require maintenance is ideal. It should only be required in rare instances.

Best Battery for Storing and Selling Energy

The utility company may charge more for peak usage times (around 4-9 pm), which is when people return from work and school.

You will need to be able store the energy you generate during the day and then sell it in the evening when the rates are at their highest.

We recommend the SimpliPhi 3.0 kWh or Discover AES 7.4kWh for this type of use.

You can store daytime energy with energy storage. It can be sold back to the utility company for profit.
The 48V lithium batteries are much more durable. Because lithium can be used in more places than a vacation home, or as a backup battery, we recommend it. In terms of cost per cycle over the battery’s life, the lithium option is just as economical as lead-acid.

These batteries will protect you against future changes in utility rates. They are a must-have if you live near high demand charges or time-of-use rates (TOU).

The Best Batteries for Marine, Remote Industrial, and Small Off-Grid Use

What if you have a smaller application such as an RV, boat or outbuilding that you own?

These are the options for compact batteries with small capacities:

Crown 6CRV220 AGM sealed battery: This is the best choice for light-use applications. This battery was originally designed to power golf carts. It has a low profile, but it can withstand heavy cycling for a long time. This battery is ideal for small homes, boats, RVs, and other applications where space is limited. It only needs to power the essentials.
Crown 12CRV110 is our choice for remote industrial applications. It can be used to power small-scale industrial equipment located in areas that are not easily accessible by power lines. It is used for lighting, monitoring, traffic signs, and pumps.

Both the 6CRV220 & 12CRV110 are identical in size and overall capacity.

6 Volts x 20 amp hours = 1320 Watt-hours

12 volts x 110 amp hours = 1320 watt-hours