8 Best Solar Batteries of 2021: Which Is the Best Solar Battery for Your Needs?
Bigger is not always better when it comes to the best batteries for solar. Overcharging or undercharging is a common problem when you choose the wrong battery. And the last thing you want is a battery to fail or not have stored energy when you desperately need it.
So here are the eight best solar battery options that vary in capacity and price, making it easier to find the perfect one for your solar system. Plus, we included options that are pretty much maintenance-free.
8 Batteries for Solar of 2021
We put together the most popular solar batteries in the solar market, with different types and capacities in mind. Plus, we’ve included ones with special safety and monitoring features to make overall maintenance a breeze. Check out the 8 Best Solar Batteries of 2021.
|Ampere Time AP-200 Battery||
||SEE ON AMAZON|
|ExpertPower EXP1233 Solar Battery||
||SEE ON AMAZON|
|CHINS Solar Battery||
||SEE ON AMAZON|
|Mighty Max ML100-12 Battery||
||SEE ON AMAZON|
|Weize 12V100-1 Battery||
||SEE ON AMAZON|
|Vmaxtanks VMAXSLR125 Battery||
||SEE ON AMAZON|
|ExpertPower EP12100 Battery||
||SEE ON AMAZON|
|Battle Born BB10012 Battery||
||SEE ON AMAZON|
Still unsure which is the best solar battery for your needs? Continue reading to know everything you need about each battery on our list.
Our best solar battery choice combines a decade of service life with a high battery capacity. But there’s so much more to this lightweight, super-sealed package.
Like our premium pick, the Ampere Time AP-200 also has a built-in BMS that protects it from overcharging and operational damage. But, this best battery for solar takes the cake because it also shuts off on its own when the temperatures drop drastically. As a result, the battery lasts way longer and can even power through 8,000 cycles.
All in all, it’s a highly efficient all-around solar panel battery bank. The carefully engineered construction makes it easy and safe to install indoors. Plus, one battery is perfect for 600W solar panels since fewer connections save more energy.
When it’s fully charged, the rugged construction is ready to take on the great outdoors. Don’t worry. It’s not as heavy as our premium pick.
It weighs 45 pounds, albeit two times more than ExpertPower. Nonetheless, it has better features to make your weekend camping trip more worthwhile. Rain or shine, expect the battery to give out consistent solar power.
If you still don’t think you’re getting enough out of this solar battery, maybe the 5-year warranty will convince you.
Next on the list is a sealed lead-acid (SLA) battery that will last you a long time without spending hundreds of dollars.
Unlike traditional flooded lead-acid batteries, this battery uses absorbed glass mat (AGM) technology. It allows the battery to operate under a broader range of temperatures. But there’s a catch — it doesn’t hold enough solar energy.
Being small has its perks, though. This 23lb is a made match in heaven if you have a 100-watt solar panel or would like to bring a backup deep cycle battery to your next fishing or camping trip.
But given its limited 33Ah capacity, it’s not the best option to power up your trolling motor. It can, fortunately, keep your fish finder running hours, with extra solar power to top up your phone. If you need more power, we have a bigger version of this model further down the list.
Our budget solar battery pick is still practical for home use. It has enough juice to power your fridge and a few lights for a few hours. Plus, depending on how much energy you need, this lead-acid battery can cycle over 1,000 times. Is that a good budget pick or what?
From the budget pick, let’s dive straight into the premium choice. Chins’ 300Ah 12V battery is a powerhouse with a price tag to match. But it just may be worth the money considering what it can do for you.
The massive 300Ah capacity (that’s about nine times more than our budget pick!) can keep an RV running for a few hours. In a residential setting, you can expect enough solar power to get you through a prolonged power outage.
If you live in a super sunny place, this battery can keep you entirely off the grid. Hook up your solar panel system to four units of this bad boy, and you’re good to go. The best part is you don’t have to worry about monitoring them.
Each unit has its battery management system (BMS) that automatically shuts off connections when it reaches maximum levels. It prevents overcharging or over-discharging, which in turn extends overall battery life. The entire solar system functions efficiently, allowing you to maximize the energy stored in each battery. Although you can safely use up 100% of the solar energy storage, it’s better to cap it at 80%. It lets you use the battery for up to 2,000 cycles.
But with that much solar power comes an obvious trade — portability.
You can argue that the price is very steep for one battery, let alone four. But connecting several deep cycle batteries to get the exact capacity will cost you thousands of dollars more. Plus, you end up losing more energy with collective self-discharge compared to just one or a few of these solar batteries.
Moving on to the next best solar batteries, we have the Mighty Max ML100-12. This SLA battery also uses AGM technology, making it maintenance-free.
It uses a calcium-alloy grid that increases the battery’s power density, allowing you to run more high voltage electronics together without overloading. Having a higher power density also means that your solar energy storage bank charges faster.
This solar battery has a service life of 10 years. But it’s only highly efficient for an average of 500 cycles at the usual 50% depth of discharge (DoD). You can extend it to over 1,000 cycles if you keep it 30% of the capacity at a time.
That said, you’ll want only to use this for emergencies. But no one wants a battery that quickly drains itself doing nothing. Luckily, this solar battery has a relatively low self-discharge rate of 3% a month. This feature lets you keep the battery floating for a long time without worrying that you won’t have enough solar energy when you need it most.
We have a lot of sealed lead-acid batteries on this list. But that’s because these solar batteries are usually cheaper than their Lithium counterparts. The Weize 12V100-1 is another basic battery like our budget pick. But it has three times the Ah rating, letting you store more power.
With over 1,000 reviews and a 4.5-star rating on Amazon, expect this battery to be handy in all sorts of situations. For example, it’s commonly used to power sump pumps in the basement. Because at over 50 pounds, this deep cycle battery is on the verge of not being portable. But that doesn’t mean you can’t take it anywhere. Its high power capacity allows it to boost electric wheelchairs or juice up RVs for a weekend camping trip.
This Amazon Best Seller comes with a one-year warranty and a 30-day refund period. Plus, the manufacturer provides excellent customer service, giving you all the first-hand information you need for your new energy storage bank.
We’re finishing off the lead-acid battery category with the 125Ah unit of Vmax Solar. It has the highest energy storage among the typical solar battery options on our list, giving you more power for a lower price.
Aside from the extra solar power storage, this backup power battery is also highly efficient and made safer. It’s designed to have 99% recombination capability, making sure you don’t breathe in toxic gases or fumes. Plus, it uses military-grade plates in its construction, making this a super heavy-duty one-year solar battery. Keeping it running in its optimal temperature range of -4~140℉ will make this solar battery last between 8-10 years.
“But what’s the catch?”
This sealed lead-acid battery is bound to be heavy between the storage capacity and durability features. We’re talking a whopping 75 pounds! That’s a lot of weight to carry around the woods during a camping trip. You’re better off keeping this big boy in one place.
The Vmaxtanks is a good-sized battery for 175W-450W solar panel kits. You can also charge this from a 120W system but make sure you don’t go past a 50% DoD.
Let’s move on to another lithium iron phosphate battery that gives off thousands of cycles, the second Expert Power battery bank on the list.
This 100Ah version of the budget pick is lightweight at just 22.6 pounds. But of course, it’s heavier on the price. Let’s talk about some features that justify the solar battery cost.
Unlike other lead-acid options, you can safely max out this model’s storage capacity. All thanks to the efficiency of its flat discharge curve design. This, in turn, allows you to get a minimum of 2,500 cycles, making it perfect for emergencies where you need more power for a more extended period.
Although the EP12100 model has a 100Ah usable storage capacity, it automatically cuts off charging or operating connections when the temperatures hit 23 °F (-5 °C). That neat feature prevents damage that can reach thousands of dollars. Yikes! But it also needs monitoring in extreme cold.
If you think about it, the safety features alone already make this battery unit worth it. The only problem is the battery inverter/charger compatibility. If you’re upgrading from a sealed lead acid unit, chances are the battery inverter you used won’t work with this lithium-ion battery system.
Last but not least, we have the only Lithium-ion battery on the list. The Battle Born BB10012 is a supercharged version of your usual AA rechargeable battery. With 100Ah, this battery can power lights and essential appliances in your house.
Using green battery technology, the BB10012 doesn’t emit toxic substances, and it charges the battery faster. As a result, you can use up the entire solar battery storage for every single cycle.
You’d think that maxing out your battery all the time will dramatically lessen the cycles you get. But despite the 100% DoD, you can still get 3,000-5,000 cycles per battery. If you’re skeptical about this, the 10-year warranty might just ease your worries.
Yes, you read that right; you get a 10-year warranty for this solar panel battery. That’s the same as the minimum service life of the battery itself. Then again, anything this good comes with a price. Be prepared to shell out almost four figures for this battery bank.
Your Guide To Buying The Best Solar Battery
Amps, Watts, Voltage, don’t they just mean electricity?
We get it. Choosing among the best solar battery options is a technical process that is ironically draining! Lucky for you, we’ve made a super easy-to-understand guide that will instead have you geeking out over the detailed specifications.
Solar Battery Types
Our list has three battery types to choose from. And each type offers something different based on your power needs and budget. Check out the summary below to see which type is the best battery for your solar setup.
|Battery type||How the solar batteries work||Pros||Cons|
|Sealed Lead Acid with Absorbed Glass Mat||-Uses glass plates that absorb electrolytes, moving oxygen molecules from one terminal to another (1)||-Least expensive|
-No maintenance compared to a flooded lead-acid battery or solar gel battery
|-Sensitive to high temperatures|
-Lowest discharge capability (30%-50%) and least cycles
|Lithium Iron Phosphate||-Uses an iron phosphate cathode that is structurally the most stable and efficient battery type||-6x more cycles than SLA solar batteries|
-More cost-effective than Lithium-Ion solar batteries
-Uses more of the battery storage (80%) (2)
|-Sensitive to low temperatures|
-Lower energy density compared to Lithium-ion solar batteries
|Lithium-Ion||-Uses either lithium manganese oxide or lithium cobalt dioxide cathode that stores the most energy (3)||-Higher energy density|
-Also capable of high usable capacity use and long battery life
|-Fewer cycles compared to Lithium Iron Phosphate batteries.|
-More unstable in fluctuating temperatures
After comparing the three battery types above, it’s easy to understand the breakdown of solar batteries on our list. There are more SLA solar battery storage options because these are the most common types available. Plus, they are easy to use, affordable, and the best battery system for solar newbies.
LiPO4 batteries are relatively new in the market. But they are gaining popularity because of their safety and efficiency.
Lastly, we only have one lithium-ion battery on the list because it’s a costly option. The Battle Born BB10012 costs almost six times that of the lead-acid batteries on the list with the same usable capacity.
Battery Capacity and Power Rating
Let’s start this section by breaking down some power terms (4).
- Amp-hour (Ah) refers to a battery’s capacity. It measures how much can be given off through several hours. If you don’t consider time, you just measure current in terms of amperage (amps).
- Voltage (V) refers to the force needed to move current around a circuit. In most cases, it’s from the battery to an electric device.
- Watts (W) is the standard measurement of power used up by appliances or electronics. You get this value by multiplying voltage to amperage. W= V x A
- Watt-hours (Wh) measures power consumption over several hours.
Explaining the relationships of each electrical unit will take a lot of time and give you a headache. This video will do a better job showing you the connection of all these units.
Now, let’s relate the usable capacity ratings of our solar batteries to see how much juice they can store. And check out what you can do with all that solar panel energy.
|Product||Ah-Rating||Watt-hour Rating||What it can power in 10 hours (5)|
|ExpertPower EXP1233||33Ah||396Wh||1 LED light (10W)1 Wifi router (10W)1 Deep freezer (19W)|
|Other solar batteries||100Ah||1,200Wh||2 LED lights (20W)1 Wifi router (10W)1 Fridge freezer (60W)1 Phone charger (7W)|
|Ampere Time AP-200||200Ah||2,400Wh||3 LED lights (30W)1 Home Internet router (15W)1 Fridge freezer (80W)2 Phone chargers (14W)1 Laptop (100W)|
|CHINS Solar Battery||300Ah||3,600Wh||5 LED lights (50W)1 Home Internet router (15W)1 Fridge freezer (80W)3 Phone chargers (21W)1 Laptop (100W)1 Apple TV (6W)49” LED TV (85W)|
All the solar batteries in our review have a 12V rating, so the amp-hour rating is the main factor in power rating.
The important thing to remember is this: the bigger the Ah value of a battery, the higher the capacity and the more power you have.
You’ll notice that a 100Ah solar battery bank can already power essential household items overnight. It also has an excellent capacity to power your RV. But with a bigger capacity, you can run more things for the same amount of time. On the other hand, you can run the same basic stuff for double or triple the time.
When using your solar battery as an emergency power source, it’s better to plug in the necessities and make them run longer. Using power derived exclusively from solar panels to run your entire home requires many high-capacity solar batteries. You want to maximize the capacity of each battery and not waste energy on multiple batteries.
Charge/Discharge Cycles and Battery Life
One battery cycle starts from a full charge, draining down to a specific capacity and then charging back up to full. Each charge/discharge cycle takes its toll on the battery system over time. But it also depends on the battery type.
Generally speaking, lead-acid batteries like the Mighty Max ML100-12 don’t give many cycles because of their chemistry and construction. Therefore, you can expect the more long-lasting lithium batteries like the ExpertPower EP12100 to outlast the lead-acid batteries by about six times (6).
In any case, all deep cycle batteries eventually perform much lower than the manufacturing standards. This is when they reach their end of life (7).
“The actual operating life of the battery is affected by the rate and depth of cycles and by other conditions such as temperature and humidity.”
Storing and operating the battery system in its specified ideal conditions is essential to extend overall battery life. Not wholly draining the battery every time also extends the service life.
Depth of Discharge
Now let’s talk more about the depth of discharge or how much power you can safely drain from the battery during a cycle. Usually, a graph in the spec sheet shows you how many bicycles you can get at a certain DoD%.
Again, the chemistry of each battery system is a significant factor (7). Lithium batteries like the top and premium pick have a deeper discharge percentage up to 100%. This feature allows you to maximize the battery’s stored energy.
For example, you can only use 50% of the Vmaxtanks VMAXSLR125’s stored energy if you want to use the battery 500 times. But if you only use 30% of the solar panel energy every time, you could use the same battery for over 1,000 cycles.
Safety and Warranty
A lot can go wrong with operating solar panel energy storage systems. And when you use this on a large scale, you need to look for safety features or a good warranty deal.
More and more home energy solutions come with built-in battery management systems. Our top pick, the Ampere Time AP-200, has a basic system that prevents overcharging, discharging, and short-circuiting. But the ExpertPower EP12100 includes an auto-shut-off feature that keeps the battery from damage in below-freezing conditions. Extreme temperature is the main enemy of solar batteries (8).
“The mechanical stresses induced by cycling and temperature gradients lead to contraction and expansion, eventually increasing the cell impedance and reducing the cell capacity.”
Choosing the right controller helps keep an eye on your solar panel batteries without built-in monitoring systems. This gadget helps prevent overcharging and other degrading factors. Solar batteries last anywhere between 3-15 years, depending on the type. But it also depends on how you maintain it while floating and operating it when it’s running.
It’s a good thing that most battery system manufacturers offer at least a 1-year warranty for their products. However, the Battle Born BB10012 still has an unprecedented record of a 10-year warranty.
No, lithium-ion batteries are not practical for large solar power systems because they are too expensive. These lithium batteries may last long and hold the most energy among the other battery types. But these solar batteries cost thousands of dollars to set up an entire system using Lithium-Ion batteries.
Plus, they can glitch in places with constant temperature changes.
Yes, you can connect solar panels directly to a battery. But this can be dangerous if the voltages don’t match. If a sudden surge of power runs through the circuit, your battery system might not have enough space for it, and it will overcharge.
Using an inverter is always a safer option to safely manage the flow of current.
To know if a solar panel is charging a battery, you need to either use a multimeter, a charge controller or check the inverter panel. These devices measure the voltage running inside the battery. If it measures up to the voltage indicated on the battery label, you know the battery is charging efficiently.
Sometimes, the voltage reading is lower, which could be because there isn’t enough sun hitting the solar panels.
- An Overview of Batteries for Photovoltaic (PV) Systems. Retrieved from: https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.401.7780&rep=rep1&type=pdf
- What are some differences between Lithium and AGM batteries? Retrieved from: https://www.sealedperformance.com.au/faq/what-are-some-differences-between-lithium-and-agm-batteries/
- Lithium Iron Phosphate Vs. Lithium-ion: Differences And Advantages. Retrieved from: vhttps://blog.epectec.com/lithium-iron-phosphate-vs-lithium-ion-differences-and-advantages
- Definition of Terms-Electrical. Retrieved from: https://www.swtc.edu/Ag_Power/electrical/terms.htm
- List of the Power Consumption of Typical Household Appliances. Retrieved from: https://www.daftlogic.com/information-appliance-power-consumption.htm
- Lithium-Ion vs. AGM Batteries: Which Is Best for Solar? Retrieved from: https://www.solarips.com/blog/2020/january/lithium-ion-vs-agm-batteries-which-is-best-for-s/
- A Guide to Understanding Battery Specifications. Retrieved from: https://web.mit.edu/evt/summary_battery_specifications.pdf
- Estimating battery lifetimes in Solar Home System design using a practical modelling methodology. Retrieved from: https://www.sciencedirect.com/science/article/pii/S0306261918310225
Hi, Im Dara. Born and raised in Farmingdale NY and I spend my time online covering alternative energy news and local developments,in the space. My mission is to help more people realise the benefits of using alternative energy. When i’m not blogging about energy you’ll find me walking my dog, working out, or practicing meditation!