Going Off the Grid? Check Out Our Best Battery for 100W Solar Panel

Whether you’re on the road or at home, you’ll find that you need to store all the excess energy your solar panels are producing.

In this article, you’ll learn about a few things to keep in mind when choosing a battery. You’ll also find reviews of our recommended batteries for a 100W solar panel. 

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ThePhoenixsun Video Series video

Buyer’s Guide: What to look for in a good solar battery

good solar battery
good solar battery

There are many batteries on the market that look alike, but not all are created equal. Choosing the correct battery is paramount to your system’s efficiency and longevity.

For a 100W solar panel, we recommend a 12v 100Ah LiFePO4 deep-cycle battery

Chemistry

The most common chemistry types for solar batteries are lead-acid and lithium-ion. Lead-acid batteries have a big market with many varieties (As can be seen below). 

Lithium-ion batteries are the result of newer technology. They have a much bigger capacity and efficiency, but they’re significantly more expensive.

The type of lithium-ion system used for solar power is the lithium iron phosphate (LiFePO4). Currently, all LiFePO4 battery cells in the world are made in China, even if the rest of the battery is made and assembled somewhere else.

If you find the cost of lithium-ion batteries prohibitive, you can opt for a lead-acid battery, which is still very viable. 

You can find a detailed comparison here, and here.

There are other types that can be used for solar batteries, such as nickel-cadmium, but they’re not recommended for home use since they are hazardous and difficult to dispose of.

The Best Battery for a 100w Solar Panel Reviews

We’ve looked at hundreds of batteries and have decided to showcase these 10.

We believe that they represent the highest performance and the best value for money.

We also made sure to represent different battery technologies, so that you can take your pick accordingly.

Battle Born LiFePO4 Deep Cycle Battery – 100Ah 12v

This reliable lithium-ion battery is about 1/3 the size of its lead-acid counterparts.

It’s also nontoxic, as it contains no acid and requires no maintenance. It can last up to 10 years!

However, with the current technology, the Battle Born can be a tad overpriced. 

Overview Specs:

  • Item Dimensions: 12.75 x 6.88 x 9 inches
  • Weighs about 31 lbs
  • Built-in battery management system (BMS) protects the battery from common causes of battery failure
  • Can be mounted upright or at any orientation
  • Lasts between 3000 and 5000 cycles

This American-made battery scores high on almost every metric, and it requires no maintenance. As long as it has decent ventilation to keep the temperature down, you can pretty much set it and forget it.

Battle born enjoys and great reputation in this business and has many satisfied customers. They offer a 10-year warranty on each purchase.

With all of that said, we still think these batteries are too expensive, especially if you’re buying several. If you’re willing to be acquainted with other options out there, you may be able to save a lot of money on a different brand.

If you want to know more about what happens inside this battery, you can watch a tear-down here.

Battle Born LiFePO4 Deep Cycle 12v 100Ah Battery Pros and Cons

ProsCons
Well-known brand
Decent weight, can be placed at any orientation
Doesn’t need maintenance
Can be discharged up to 90%
Doesn’t produce harmful gasses
Can handle 3000 cycles and up
Long-lasting (up to 10 years)
Quick charging even when cloudy
Very expensive (overpriced for current technology)
A bit bulky for a lithium-ion battery

Renogy Smart Lithium Iron Phosphate Battery – 100Ah 12v

A more affordable lithium-ion solar battery. Renogy is a well-known brand in the field, with amble documentation and customer support. You’ll still be getting all the benefits of lithium-ion technology at a smaller price.

Overview Specs:

  • Item Dimensions: 6.8 x 7.4 x 11.4 inches
  • Weighs about 26.01 Pounds
  • Built-in battery protection system
  • Can be mounted upright or at any orientation
  • Over 2000 cycles

This Renogy is so light at 26lbs; it’s even smaller and lighter than the Battle Born! If you can’t carry heavier weights, or if you need it for a boat or van, then this is definitely something to consider.

Renogy is definitely a well-known brand in this market. You can never be entirely sure of warranties, but there are many instances of customers returning a defective product and having it fixed or replaced. Also, their customer service is more than happy to help you with your setup.

These batteries are full of neat features.

For example, there’s a “shelf switch” that isolates the battery without needing to disconnect it from your system.

Additionally, if you’re using several of these in parallel, you’ll find that each one displays its voltage separately, which is very useful while testing your setup.

Little details like these can only be made from experience.

These batteries should never be mixed with other types in the same setup. They’re also not recommended for freezing temperatures, and may need an insulated box if you live in a colder climate.

You can watch this video tutorial from Renogy to learn how to set it up. You can also watch this video if you’re interested in the inner workings of the battery.

Renogy Smart Lithium Iron Phosphate 12v 100Ah Battery Pros and Cons

ProsCons
Lightweight and small
Doesn’t need maintenance
Can be discharged up to 90%
Doesn’t produce harmful gasses
Can last between 5-7 years depending on use
Quick charging even when cloudy
Still significantly more expensive than lead-acid
2000 cycles are not that impressive
Can only work in a parallel setup, which means that if you need several batteries, it’s not compatible with other types

SOC Lithium Iron Phosphate LiFePO4 Deep Cycle Battery – 100Ah 12v

This SOK battery has all the perks of a lithium-ion battery at an even smaller price tag.

The main difference is that the top is not sealed, which means it can be opened and the inner parts can be replaced. If you ever need to replace certain parts, SOK promises free maintenance. 

To get an idea for how much you can save, a SOK battery costs about 50% less than a Battle Born battery of the same capacity.

Overview Specs:

  • Item Dimensions: 10.2 x 7.9 x 8.1 inches
  • Weighs about 26 lbs
  • Built-in smart battery management system
  • Can be mounted upright or at any orientation
  • Should last between 4000 and 8000 cycles 
  • Free maintenance, detachable cover, replaceable parts

SOK batteries are made in China. They also make their own LiFePO4 cells, which could explain the massive price cut. Manufacturers from other countries would have to import the cells from China.

This brand and model are quite new, so no long-term usage data is available yet. However, what we have so far is very promising.

Choosing between this battery and other LiFePO4 will come down to whether you’re willing to pay more for a well-established brand, or if you’re willing to risk buying a relatively-unknown one for a significant price cut.

What we like about this battery is that the top is removable and many of the parts can be replaced if defective.

We also like that it can be connected to other batteries of different voltage ratings, so it gives your setup more flexibility.

For an in-depth technical review and a look inside the battery, watch this part 1 and part 2 of this video series.


SOK LiFePO4 Deep Cycle 12v 100Ah Battery Pros and Cons

ProsCons
Bargain price for a LiFePO4 battery
Lightweight, can be placed at any orientation
Replaceable parts
Can be discharged up to 80%
Doesn’t produce harmful gasses
Between 4000 and 8000 cycles
Free maintenance and replacement parts available
New and unknown model/brand.
Not enough customer feedback
The removable parts may be prone to failure if not serviced properly

Vmaxtanks VMAXSLR125 AGM Rechargeable Deep Cycle battery – 12v 125Ah

If you prefer good old fashioned lead-acid batteries, then the Vmaxtanks is one of the best out there.

It’s a sealed valve AGM battery, which means that it doesn’t require much maintenance. However, you’ll need to have good understanding of electrical circuits in order to set it up without problems.

Overview Specs:

  • Item Dimensions: 6.8 x 12.9 x 8.7 inches
  • Weighs about 75 Pounds
  • VRLA no-maintenance battery
  • Can be mounted sideways and placed indoors
  • Minimal ventilation required
  • About 1000 cycles

The Vmaxtanks battery is ½ to 1/4 the price of most lithium-ion batteries on the market, and yet you can easily get about 3 years of use out of it. 

AGM stands for “absorbed glass mat”. Soft glass mats allow for more lead to fit into the same battery, giving the battery a higher capacity in a smaller space.

The tight fit also prevents parts from moving around, which makes the battery less prone to failure. To learn more about AGM batteries, visit this link.

AGM batteries can be sensitive about their charging profiles. We recommend using a high quality smart charger to avoid problems. It also goes without saying that you should read the manual.

Vmaxtanks VMAXSLR125 AGM Deep Cycle 12v 125Ah battery Pros and Cons

ProsCons
Significantly cheaper than any lithium-ion battery
Sealed, doesn’t need maintenance
Minimal ventilation required
About 3 years of usage
AGM batteries charge faster than other lead-acid batteries
Resilient, heavy-duty construction
Rather heavy at 75lbs
Requires a bit of handiness to setup
Shouldn’t be discharged below 50%

Renogy Deep Cycle Hybrid Gel battery – 12v 125Ah

Another Renogy battery like the Vmaxtanks battery, this one is also a sealed valve-regulated lead-acid battery. It uses a unique hybrid gel technology.

Gel batteries have a similar construction to flooded batteries, except they use an electrolyte gel in place of the liquid.

Because of this, the battery can be safely sealed and the electrolyte material doesn’t need maintenance. The gel has a very low self-discharge rate when compared to flooded batteries (about 3% per month).

Overview Specs:

  • Item Dimensions: 12.9 x 6.8 x 8.7 inches
  • Weighs about 63.9 Pounds
  • VRLA no-maintenance battery
  • Should be placed upright. May be placed sideways if necessary, but never upside-down.
  • Should last about 3 years

The Vmaxtanks battery is ½ to 1/4 the price of most lithium-ion batteries on the market, and yet you can easily get about 3 years of use out of it. 

AGM stands for “absorbed glass mat”. Soft glass mats allow for more lead to fit into the same battery, giving the battery a higher capacity in a smaller space.

The tight fit also prevents parts from moving around, which makes the battery less prone to failure. To learn more about AGM batteries, visit this link.

Renogy is definitely a well-known brand in this market.

You can never be entirely sure of warranties, but there are many instances of customers returning a defective product and having it fixed or replaced.

Also, their customer service is more than happy to help you with your setup.

AGM batteries can be sensitive about their charging profiles. We recommend using a high quality smart charger to avoid problems. It also goes without saying that you should read the manual.

You can watch this video tutorial from Renogy to learn how to set it up. You can also watch this video if you’re interested in the inner workings of the battery.

Pros and Cons

ProsCons
Significantly cheaper than any lithium-ion battery
Sealed, doesn’t need maintenance
Minimal ventilation required
About 3 years of usage
AGM batteries charge faster than other lead-acid batteries
Resilient, heavy-duty construction
Rather heavy at 75lbs
Requires a bit of handiness to setup
Shouldn’t be discharged below 50%

Frequently Asked Questions

What is a deep-cycle battery?

Deep cycle batteries look similar to car batteries. However, the key difference is that Car batteries (or starter batteries) are designed to put out short bursts of energy (such as when you’re starting a car). While deep-cycle batteries are meant for discharging smaller amounts of power over longer periods, making them ideal for renewable energy use.

How do I size my battery bank?

There are many variables when it comes to sizing your battery bank. If you only need one battery for your 100 watt solar panel, a 12v 100Ah battery should be fit for most purposes.
If you have a more complicated rig, you can use a battery bank calculator or contact the manufacturer. Determining your bank size early on is important, because it’s not recommended to mix up old and new batteries in the same system. 

Difference between flooded and sealed lead-acid batteries

Flooded lead-acid batteries. These batteries have visibly large separators, thick plates, and a high-density paste material. Their design helps them resist corrosion, giving them a longer lifespan. “Flooded” means that the separators are fully submerged in electrolyte fluid. 

We don’t recommend flooded batteries for personal or home use, because they produce toxic vapors and require maintenance. There are a lot of hassle-free, cheap options on the market today that make them seem unnecessary. 

Sealed valve regulated lead-acid batteries, also known as VRLA maintenance-free batteries. These batteries are sealed and don’t need the user to maintain the fluid levels, they also don’t produce harmful discharges as much as flooded batteries. 

VRLA batteries have many types, including AGM batteries, gel batteries, lead-carbon batteries, and tubular gel OPzV batteries.

For a more detailed comparison, check this link.

Final Verdict

We highly recommend the SOK battery for most uses. It falls right in the middle of the price range for deep-cycle batteries, but it’s actually very affordable for a lithium-ion battery. It has all the advantages of higher-end batteries such as the Battle Born at half the price. 

SOK batteries have replaceable parts and the company offers free maintenance, so it can be salvaged even if it fails. If you get a more expensive battery and it fails, you may still have the warranty, but you can’t actually open it and replace the defective part.

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