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 the five best batteries for a 100W solar panel.
Contents
Buyer’s Guide: What to look for in a good solar battery
Many batteries on the market 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 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 lithium iron phosphate (LiFePO4). Currently, all LiFePO4 battery cells worldwide 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.
Other types 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 5.
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
- BUILT-IN BMS: BMS stands for "Battery Management System" - the brain of our deep cycle lithium batteries. Our BMS protects your battery from most common causes of battery failure, such as temperature volatility or ground faults. The BMS regulates the amount of power taken out of the battery and acts as a shut-off system to protect the li-ion cells (and you) from unsafe operating conditions.
- LITHIUM ION TECHNOLOGY: Unlike Lead Acid batteries, Battle Born's deep cycle lithium ion batteries have unlimited mounting capability, exceptional longevity, and are more cost effective. When factoring time and cost into your purchase, our lithium ion battery banks come out ahead every time. Plus, Li-Ion batteries can be safer than Lead Acid batteries, which have no protection against ground faults.
- GREEN ENERGY BATTERIES: Made from 100% safe, nontoxic, renewable energy, Battle Born Batteries last for more cycles and can be charged and discharged repeatedly (and charge faster than any other battery). We make our renewable, sustainable green energy batteries because they’re simply better than anything else out there, including other green batteries.
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, the Battle Born can be a tad overpriced with the current technology.
Overview Specs:
- Item Dimensions: 12.75 x 6.88 x 9 inches
- It weighs about 31 lbs
- A built-in battery management system (BMS) protects the battery from common causes of battery failure.
- It can be mounted upright or at any orientation
- It 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
| Pros | Cons |
| Well-known brand Decent weight can be placed at any orientation It doesn’t need maintenance Can be discharged up to 90% It 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 |
- BUILT-IN BMS: BMS stands for "Battery Management System" - the brain of our deep cycle lithium batteries. Our BMS protects your battery from most common causes of battery failure, such as temperature volatility or ground faults. The BMS regulates the amount of power taken out of the battery and acts as a shut-off system to protect the li-ion cells (and you) from unsafe operating conditions.
- LITHIUM ION TECHNOLOGY: Unlike Lead Acid batteries, Battle Born's deep cycle lithium ion batteries have unlimited mounting capability, exceptional longevity, and are more cost effective. When factoring time and cost into your purchase, our lithium ion battery banks come out ahead every time. Plus, Li-Ion batteries can be safer than Lead Acid batteries, which have no protection against ground faults.
- GREEN ENERGY BATTERIES: Made from 100% safe, nontoxic, renewable energy, Battle Born Batteries last for more cycles and can be charged and discharged repeatedly (and charge faster than any other battery). We make our renewable, sustainable green energy batteries because they’re simply better than anything else out there, including other green batteries.
Renogy Smart Lithium Iron Phosphate Battery – 100Ah 12v
- 【Premium BMS Circuit】 Incredibly advanced BMS provides over 20 protections designed to allow a peak current of 150A to pass through, deliver up to 1C charging and 1.3C discharging during an emergency. 50% more heat dissipation area will maximize the safety of your off-grid use.
- 【The Ultimate Quality】 The next-level pouch cells surpass severe high temperature and puncture tests to avoid fire or explosion. The battery cell not only passes the UL1642 but also offers over ten years of lifespan with more than 4000 cycles (80% DOD).
- 【Activation Switch】With the activation switch cable, now for the first time, you can turn on or off multiple batteries in parallel to ensure the safety of installation and use.
A more affordable lithium-ion solar battery. Renogy is a well-known brand in the field, with ample 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
- It 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 need it for a boat or van, this is something to consider.
Renogy is 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
| Pros | Cons |
| Lightweight and small It doesn’t need maintenance Can be discharged up to 90% It doesn’t produce harmful gasses It can last between 5-7 years depending on the use Quick charging even when cloudy | Still significantly more expensive than lead-acid 2000 cycles are not that impressive It can only work in a parallel setup, which means that if you need several batteries, it’s not compatible with other types. |
- 【Premium BMS Circuit】 Incredibly advanced BMS provides over 20 protections designed to allow a peak current of 150A to pass through, deliver up to 1C charging and 1.3C discharging during an emergency. 50% more heat dissipation area will maximize the safety of your off-grid use.
- 【The Ultimate Quality】 The next-level pouch cells surpass severe high temperature and puncture tests to avoid fire or explosion. The battery cell not only passes the UL1642 but also offers over ten years of lifespan with more than 4000 cycles (80% DOD).
- 【Activation Switch】With the activation switch cable, now for the first time, you can turn on or off multiple batteries in parallel to ensure the safety of installation and use.
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 of 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
- It weighs about 26 lbs
- Built-in smart battery management system
- It 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, explaining 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 the removable top, 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
| Pros | Cons |
| Bargain price for a LiFePO4 battery Lightweight can be placed at any orientation Replaceable parts Can be discharged up to 80% It doesn’t produce harmful gasses Between 4000 and 8000 cycles Free maintenance and replacement parts are 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
- 12 Volt 125Ah Group 31 AGM Deep Cycle Heavy Duty Battery
- Military grade custom made plates
- Float service life span of 8 to 10 years
If you prefer good old-fashioned lead-acid batteries, then the Vmaxtanks are 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 a good understanding of electrical circuits 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
- It 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, yet you can easily get about 3 years of use out of it.
AGM stands for “absorbed glass mat.” Soft glass mats allow 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, making 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
| Pros | Cons |
| 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% |
- 12 Volt 125Ah Group 31 AGM Deep Cycle Heavy Duty Battery
- Military grade custom made plates
- Float service life span of 8 to 10 years
Renogy Deep Cycle Hybrid Gel battery – 12v 125Ah
- 【Maintenance Free & No Leakage】This battery is comprised of gel instead of liquid, so there is no maintenance required to keep the battery working properly. Manufactured with an advanced valve regulated technology, Renogy Deep Cycle Hybrid GEL Batteries save you from acid leakage and frequent maintenance.
- 【Extended Service Lifetime】Corrosion-resistant grids enable a design life of up to 12 years in standby applications and more than 750 charge/discharge cycles at 50% DOD in cyclic applications.
- 【Longer Shelf Life】Made of high purity materials, Renogy Deep Cycle Hybrid GEL Batteries reduce the monthly self-discharge rate below 3% at 77℉ (25℃), which is 5 times lower than their Flooded counterparts. No need to recharge the dormant battery frequently.
Another Renogy battery like the Vmaxtanks battery 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 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
- It should be placed upright. It may be placed sideways if necessary, but never upside-down.
- It should last about 3 years.
The Vmaxtanks battery is ½ to 1/4 the price of most lithium-ion batteries on the market, yet you can easily get about 3 years of use out of it.
AGM stands for “absorbed glass mat.” Soft glass mats allow 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, making 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.
Renogy Deep Cycle Hybrid Gel battery – 12v 125Ah Pros and Cons
| Pros | Cons |
| 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% |
- 【Maintenance Free & No Leakage】This battery is comprised of gel instead of liquid, so there is no maintenance required to keep the battery working properly. Manufactured with an advanced valve regulated technology, Renogy Deep Cycle Hybrid GEL Batteries save you from acid leakage and frequent maintenance.
- 【Extended Service Lifetime】Corrosion-resistant grids enable a design life of up to 12 years in standby applications and more than 750 charge/discharge cycles at 50% DOD in cyclic applications.
- 【Longer Shelf Life】Made of high purity materials, Renogy Deep Cycle Hybrid GEL Batteries reduce the monthly self-discharge rate below 3% at 77℉ (25℃), which is 5 times lower than their Flooded counterparts. No need to recharge the dormant battery frequently.
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 more extended 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. It is important to determine your bank size early on 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 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 many 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.
