5 Best Deep Cycle Batteries For Solar Power Storage

The world has witnessed numerous energy crises in the years since the Industrial Revolution. But it never has been as bad as it is now.

The basic reason for our present predicament is the overdependence on fossil fuels. The energy demand across the world seems to be growing at an alarming pace, which is not surprising. What is surprising is the way we continue to hold on to fossil fuels and refuse to let them go despite knowing the negative consequences of our actions for more than half a century!

In the last decade or two, there have been some positive trends in the energy sector. Solar energy is gaining a foothold in energy production, riding on the back of all the financial incentives and rebates being offered. This is definitely a positive development though solar power has numerous challenges in the path ahead.

One of the most prominent challenges faced by solar power is intermittency. Being completely dependent on sunlight, solar energy production grinds to a halt during night hours. This single setback adds a whole lot of dimensions to the challenge.

All the troubles of the unreliability of solar power can be overcome as if by the wave of a magic wand with a solar battery. These are devices to store energy generated when the sun is shining for use when it is not.

Pairing a solar panel installation with a solar battery or a battery bank can give you the freedom you want from fossil fuel-generated grid energy.

Before you go solar battery shopping, you need to have a better understanding of them to make an informed choice. This article explores the world of solar batteries, especially the deep cycle ones, and comes up with answers to your queries on the topic. You will also find in this article a list of the best 5 deep cycle batteries for storing solar energy. The information here will help you find the best solar battery for your needs.

Solar batteries for the solar panel system

A battery is an electrical device for storing electricity. Just like a water tank stores water for later use, batteries store energy for use in the future. A point to remember is that batteries do not produce electricity on their own.

When electricity is fed to the battery, it converts the electrical energy into chemical energy and stores it. This process is called charging. When you want to draw electricity from the battery, it discharges the stored energy in it after reconverting the chemical energy into electrical energy.

Types of batteries

Batteries are classified based on their application as well as construction. Examples of batteries based on application are marine, automotive (starting), and deep cycle. The major construction type batteries are lithium-ion, flooded lead-acid, sealed lead acid, gel, and AGM (absorbed glass mat) batteries.

Each one of the construction type batteries listed above can be used as a solar battery. They differ in their uses, benefits, price, lifespan, features, and more. There is no simple answer to the question, “Which among these are best suitable for solar backup?”. You need to consider the various factors and your requirements to arrive at this answer.

Among the application-type batteries, automotive batteries are used only for starting and running engines. Deep-cycle batteries are designed to discharge up to 80 % of the stored energy and can be charged and discharged multiple times. A marine battery is a hybrid of these two. Of these three, deep-cycle batteries are the best suited for pairing with solar installations.

Some more things to know about deep-cycle solar batteries

When shopping for solar batteries, remember that the battery has to be a match for the solar panel. If you have a 12V solar panel, you should pair it up with a 12V solar battery. Though 12V is the most common among solar panels and solar batteries, there are 24V solar panels also on the market.

Here are some more features to check in the battery before buying.

Power rating: This is an indication of the amount of energy the battery can discharge at once. It is denoted in kilowatts (kW). This will give you an idea of how many devices you can use at the same time.

Capacity: Solar battery storage is the maximum amount of energy the battery can store. This will give you an idea of how long the stored energy will last.

Roundup efficiency: This is an indication of the conversion efficiency of the battery. For instance, if 100 watts of energy is fed into the battery and if it can discharge 80 watts, the roundup efficiency of the battery is 80%. The higher the percentage, the better it is for you.

Lifetime: This is measured using three different criteria – years of operation, throughput, and discharge cycles. Throughput is the total amount of energy the battery can handle over its lifetime.

Chemistry: This is one aspect of the battery that has a say in most of the above factors. The chemistry of a battery refers to the actual chemical compound used in the battery to store energy.

How to choose the right battery for your solar system?

Besides the technical aspects of the batteries listed above, you also need to consider these points when selecting solar batteries.

Ease of installation
Time required for charging
Your budget limitations
The length of the warranty offered by the manufacturer

5 best batteries for solar power storage

1. Renogy 12V 100Ah LiFePO4 Deep Cycle Lithium Battery

One of the most trusted battery makers, Renogy, presents this perfect companion for your solar panels. Being a lithium-ion battery, it comes with a long lifespan of more than 4000 cycles of charging and discharging. That is a lot compared to flooded lead-acid batteries.

This Renogy solar battery offers 100Ah of continuous discharge current, a wide range of operation temperatures, and an auto-balancing function. It comes equipped with a smart battery management system to prevent overcharging, overheating, and short circuits, besides monitoring and managing the charging and discharging process.

As it is a lithium-ion deep cycle battery, it is more lightweight and portable than lead-acid batteries. The activation switch allows you to change into shelf mode to lower the self-discharge rate. The real-time monitor helps link various devices in the system and allows you to monitor the real-time charging status in the Renogy DC Home app.

Highlights:

Long lifespan
Powerful performance
Low self-discharge
Protection against abnormalities
Auto-balancing function
Real-time monitor

2. Vmaxtanks VMAXSLR125 AGM 12V 125Ah SLA Rechargeable Deep Cycle Battery

This 125 Ah deep-cycle battery is made using AGM technology. This is not as efficient, lightweight, or sophisticated as lithium batteries, but the advantage is mostly in the price difference. But this is a step up from the lead-acid batteries.

Vmaxtanks AGM battery features military-grade and custom-made plates for superb deep-cycle capabilities. The heavy-duty plates provide an extra lifespan and an extended margin of performance. Whether you want it for your everyday needs or emergency power backup, this battery is designed for heavy-duty applications.

This AGM battery is built to withstand repeated charges/discharges and continue to remain charged. In standby mode, its self-discharge is minimal or negligible.

As the battery is sealed, there is no worry about leakage. Unlike lead-acid batteries, there is no need for maintenance. No need to add water or check the specific gravity of the electrolyte.

Highlights:

Well-built battery
Long lifespan
Maintenance-free
Leak-proof
99% recombination to ensure no toxic fumes
Ideal for positioning on the side or at an angle

3. WindyNation 100Ah 12V AGM Deep Cycle Solar Battery

A great product from one of the most trusted brands in solar batteries. This WindyNation AGM battery is the best AGM battery for solar and a perfect addition to your home solar installation, especially if you want to avoid the hassles of maintenance of lead-acid batteries and the exorbitant price of a lithium-ion battery.

This sealed lead acid battery comes with 99.995% virgin lead to offer you extra power and a longer lifetime. A battery designed specifically for use with solar systems, this AGM battery can be used in a variety of settings – off-grid, marine, RVs, and portable needs.

The heavy-duty plates in this battery are built for deep discharges and repetitive charges.

If your energy demand is low, this WindyNation model is a great option. The reliable brand name, affordability, and low maintenance are the main selling points of this deep cycle AGM battery.

Highlights:

Affordable
Low maintenance
Low discharge
Lifespan of 10-12 years
Leak-proof and non-spillable
1-year warranty

4. Universal Power Group 12V 100Ah Solar Wind AGM SLA Deep Cycle VRLA Battery

This sealed lead acid battery is an excellent choice if you are searching for a battery that can be placed in any awkward position. Though it is a basic model, it comes with the flexibility of positioning it even upside down.

This near-zero maintenance battery is ideal for teaming up with solar panels for a 24×7 supply of electricity even for off-grid users. The affordability of this battery is one of the main reasons for its immense popularity in solar homes.

Unlike most other AGM batteries, this one offers a range of voltage choices – 12V, 24V, and 48V. This would be helpful for at least some with unique setup requirements.

This spill-proof battery is built for heavy use. It is resistant to shock and vibration.

Highlights:

Budget-friendly
Reliable and long-lasting
Compatible with a variety of devices
Easy to install
Ideal for continuous usage
1-year warranty

5. Battle Born Batteries LiFePO4 Deep Cycle Battery

This lithium-ion battery from the Battle Born stables is the best deep cycle battery for solar, especially for those looking for a safe and stable 12v deep cycle battery for the solar system. The lithium-ion technology used in this battery gives it the flexibility of positioning, exceptional longevity, and reliability. Cost-effective and lightweight, this battery is made from 100% nontoxic materials.

The built-in battery management system offers excellent protection to the battery from temperature volatility and ground faults. It also shuts down the battery use if the charge in it reaches unsafe levels.

Battle Born LiFePO4 battery provides 100 Ah continuous output and can be used with 12V, 24V, 36V, and 48V systems. This lightweight battery can fast recharge and last for 3000-5000 cycles. This is a true deep cycle battery with 100% discharge depth.

Highlights:

Lightweight and versatile
Fast recharge
100% discharge depth
Can withstand temperature volatility
3000-5000 cycles
8-years full replacement warranty

Bottom line

Shopping for a solar battery is not like buying groceries from the supermarket. Unless you invest some time understanding your expectations and the system requirements of your solar installation, you may end up with an unsuitable or undesirable battery.

All you need to do is check the basic specifications to ensure that the battery matches your solar system and is capable of meeting your energy demand.

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