Gel Batteries: Everything you need to know

by Tyler Deken November 8th, 2022

Key Points

  • Gel batteries are a relatively expensive solution, suited for use in small-scale solar setups
  • They have dozens of applications with vehicles and off-the-grid setups 
  • Gel batteries will not leak, are vibration-resistant, and have no maintenance fees
  • Charging a gel-battery is an involved process that must be closely monitored 

What is a Gel Battery?

Any solar gel battery is a deep-cycle battery, which differs from your conventional automotive battery. 

Vehicles use starting, lighting, and ignition (SLI) batteries, which are composed of very thin lead plates that produce a sudden burst of energy, allowing your car to start quickly. 

If you were to hook up an SLI battery to a solar setup, you would run into some frightening issues. 

Deep-cycle batteries are made up of thicker lead plates that result in a slower, but more balanced production of energy, lasting longer than SLI batteries. 

Stringing them together creates a battery bank that has applications for solar energy storage, but at a smaller scale compared to a lithium-ion battery.

Chances are, if you have been looking into a solar setup for your home, you have read about sealed lead-acid batteries, and lithium-ion and absorbent glass mat (AGM) batteries. 

While it may be tempting to simply go with the one you have read the most about, you’ll want to select the right type of battery for your residential solar, or niche solar setup. 

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Can you Pair Gel Batteries with Solar Panels?

Similar to other lead-acid battery options, gel batteries can be a brilliant choice to pair with your residential solar panel system. 

That being said, for most homeowners, a lithium-ion battery will be a much better fit. Take a look at products like the Tesla Powerwall 2, SunPower SunVault, Enphase IQ and the LG Chem RESU. 

All of these are able to keep up with the extremely high energy input from your solar panel system, and effortlessly manage the demands of your home energy system. 

Gel batteries are more suited for smaller, off-the-grid solar systems with lower energy demand than your suburban home. 

If you have a small cabin, or a remote solar station powering some agricultural utilities, you may be better off going with a gel or AGM battery bank. 

Why? In most cases, virtually no maintenance is needed to keep them up and running. Combine that with a lower initial investment, and you have a great candidate for some off-grid power storage. 

Are 12V 1000AH Gel Batteries Good for Solar? 

Simply put, there are limited applications for solar energy storage. Most solar setups will not work well with deep-cycle gel batteries. 

This is because of their cost to energy ratio, as well as the amount of energy these batteries are able to store and produce. 

As mentioned above, gel batteries are great for small, off-grid solar energy systems. Other than the example above, you may find gel batteries in: 

  • RV solar setups
  • Solar setups on boats 
  • Tiny home setups 
  • Van solar panels 
  • Small, remote cabins 

If you are hoping to use a gel battery for your home, look elsewhere, as they are not a practical investment for the average residential solar system. 

How to Charge Gel Battery with a Solar Panel? 

Before charging a gel battery, you’ll need a few key components: 

  • A solar array with 12V or 24V capability
  • Solar Charge Controller (BMS)
  • Battery Capacity between 40-100Ah/12V/24V

Most solar charge controllers will have 3 terminals, the (+) Positive inflow, (-) Negative inflow, and the output terminal, or (+) Positive outflow to the battery. 

Using a 40Ah to 100Ah battery is ideal for remote setups, because it allows energy storage during sunny days. 

You will want to connect your solar panels directly to your charge controller. This will regulate how much current is allowed to flow into the battery, preventing the damage. 

Always be sure to add fuses on both outputs of the charge controller. 

Connect your negative and positive wire from the panel to the corresponding position on the charge controller, and install fuses on both ends of the wires leading to your gel battery. 

Once your system is installed, be sure to use a multi-meter to measure the amount of electricity flowing into your battery from your solar panels. 

What are the Pros and Cons of Gel Batteries?


  • Maintenance Fees: Thanks to the fact that the battery is made from gel, and not liquid, there is almost no maintenance required on gel batteries. 
  • No Leaks: Gel batteries are sealed, and come equipped with a value to remove excess pressure. Thanks to this system, the mixture will not breach the battery casing. 
  • Install them Anywhere: Thanks to their unique composition, gel batteries can be installed in almost any location, and in any position, giving them countless applications. 
  • Minimal Risk: Unlike liquid lead-acid batteries, which can have a dangerous cleanup process, gel batteries will not leak if the casing becomes damaged, making them inherently safer. 
  • Vibration Resistant: Wet cell batteries are extremely prone to issues from vibrations, whereas gel batteries are not, making them great for mobile setups that are prone to constant vibration. 
  • No Fumes: Minimal fumes are created as a result of use, making them great for installations where minimal ventilation is available, and giving them the ability to be charged almost anywhere. 
  • Resistant to Dying from Discharge: Because they are deep-cycle batteries, they can be discharged lower than a conventional wet-cell battery. 


  • Cost: On average, gel batteries cost an extra 31% over conventional wet cell batteries. The hefty price tag is the biggest complaint about gel batteries. 
  • Charging Time: You’ll need to allocate extra time to charge a gel battery, and you simply can’t walk away during its recharging period. If you let it overcharge, it can cause voids in the electrolyte, resulting in irreversible damage to the cell. 
  • Heat Control: Like any battery, gel batteries are prone to the effects of damage from heat. Limiting your battery’s exposure to direct sunlight and allowing it to ventilate is critical. 

What is an AGM Battery? 

  • AGM means absorbent glass mat and refers to the fine glass fiber separator between the positive and negative plates that helps absorb all the battery acid
  • AGM Batteries are advanced lead-acid batteries

Agm vs. Gel Battery for Solar: Which is Better? 

Ultimately, while both batteries have their applications, AGM batteries actually outsell gel batteries by a ratio of almost 100:1. 

The price tag of gel batteries is only justified if the battery must withstand constant jarring or vibration

Which Is Cheaper: Gel or Lithium?

Average Cost of Gel and AGM Batteries, not Including the Federal Solar Tax Credit

It is important to look at each battery. It is important to look past the price tag and do extensive research on which type of battery will end up being more cost-effective.

If you are strictly looking at the price tag, then you could end up buying a battery that doesn't work well with your setup. 

In most cases, you can expect to pay around $7,500 for a lead-acid battery in a complete home energy system. 

With respect to a lithium-ion battery setup, you can expect to pay around $12,000 for a top-of-the-line setup. 

These prices will vary depending on the system size and the complexity of the installation. 


Are Gel Batteries a Good Investment? 


Provided that you intend to use your batteries to store solar energy from your solar panel setup, both types of batteries would qualify for the Federal Solar Tax Credit

This would save you 26% in equipment and installation costs. 

Factoring in the credit, you should expect to pay around $5,550 for a Gel battery setup, and $8,800 for an AGM battery setup.  

When it comes to “hidden costs,” the first that comes to mind is the lifespan of both batteries. 

The average lead-acid battery will last for around 7 years. Amortizing it over its lifespan, you end up with a yearly cost of $785.

Despite lithium-ion batteries growing in popularity, they still remain the more expensive investment. Amortizing their cost over 10 years, which is their effective lifespan, and you’ll end up paying $880 per year. 

Lithium-ion batteries are going to see a continual decrease in price as they become more popular, provided that global market conditions remain stable. 

In the future, it is highly probable that lithium-ion batteries will be the market standard, making them a phenomenal long-term investment for you and your family to make. Spark Change is partnered with Home Grid Energy, the most powerful batteries available. Bundle your battery with your solar system and receive a $7500 cash rebate from Spark Change.

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