For a couple of years now, it's been an open secret that having a solar panel system is a tremendous long-term investment for various reasons. You end up saving plenty of money on energy costs but also do the environment a massive favor. To maximize your off-grid power system, you need the best solar battery to store all the solar energy your panels collect throughout the day, and you make use of it at night or on cloudy days.
Choosing the right solar battery for your solar system is critical because different types of batteries offer varying levels of energy efficiency, capabilities, storage and cost-effectiveness. To help you narrow down your selection, we have mustered an extensive guide on the best batteries for solar setup based on their characteristics and technical specifications. So let's get right to it and work out the best solar battery for your panel system:
Types of Solar Batteries
Before we walk you through the best solar batteries the market has to offer, we want to help you better understand what to look for when choosing a solar battery. Part of this involves knowing the differences between the various types of batteries. There are several kinds of battery types to consider; however, we always recommend going for deep-cycle batteries.
Why deep-cycle batteries? These batteries have the ability to complete a discharge-recharge cycle multiple times. They are designed to store electricity and release a steady flow of power over an extended period of time. Additionally, deep-cycle batteries are built with thick lead plates that also help prolong the battery's lifespan.
a). Lithium-ion Batteries
Lithium-ion batteries are a great option because they're fairly easy to install and have relatively low maintenance. Furthermore, they have a higher energy density, are considerably lighter and offer an extended lifespan. This makes lithium batteries some of the most popular for home solar systems.
b). Flooded lead-acid Batteries
These are also known as wet-cycle batteries. They contain a liquid in an open case and dissipate hydrogen gas. Flooded lead-acid batteries are cheaper but they also require more maintenance because they must be kept upright and well-ventilated. More so, these batteries have to be regularly monitored and refilled with distilled water.
c). Sealed lead-acid (AGM) Batteries
For sealed lead-acid batteries, the valve-regulated battery is arguably the maintenance-free option. They are built to keep the battery from getting to its gas-generating limit as it charges, which subsequently prevents water depletion and gas dispersal. On the flip side, this means valve-regulated batteries can never be fully charged.
d). Solar gel Batteries
Gel batteries, or gel cells, function closely similar to sealed-acid batteries, also using gel electrolytes. These batteries handle movement quite well -unlike lead-acid batteries that have to be kept upright- making them an excellent option for campers, vans and boats.
Our top picks for the best batteries for solar panels include:
1. ExpertPower 12V 33Ah Rechargeable Deep Cycle Battery
- Genuine ExpertPower Battery - The Most Trusted And Highest Reviewed Sealed Lead...
- Battery Type - 12 Volt 33Amp/10 Hour Sealed Lead Acid Battery
- Quality Assurance - Crafted Wtih A Rugged Construction, Our SLA Batteries Are...
- User Friendly - Easy, One-Time Installation Of Our Maintenance Free and Valve...
The ExpertPower 12V 33Ah is an absorbed glass matt (AGM) battery, which has several benefits. This seal lead-acid battery has a wide temperature range, meaning it never gets too hot. Plus, it can handle extremely hot or cold outdoor temperatures.
It's a fairly small battery that won't be taking too much space. More so, the ExpertPower 12V 33Ah comes with a relatively easy one-time installation feature. Plus, it's a valve-regulated battery meaning it's virtually maintenance-free. As far as safety standards go, it's UL, DOT, CE, ISO 9001, ISO 14001 and ISO 18001 certified.
As the name suggests, it's a 12 volt 33 Amp per 10 hours deep-cycle battery, meaning it can handle quite a substantial charge that'll last a more than decent time. Additionally, it has a 20-hour charging time at 12 volts/2 Amps. Lastly, this solar battery is made of an incredibly durable shell for extra resistance to the elements.
2. Renogy Deep Cycle AGM Battery
- Maintenance Free: Manufactured with thick absorbent glass mat (AGM) separators...
- Excellent Discharge Performance: Proprietary quinary alloy plates and specially...
- Long Shelf Life: Made of high purity materials, Renogy Deep Cycle AGM Batteries...
- Wide Operation Temperature Range: Improved electrolyte formula ensures stable...
- NOTE: We highly recommend installing the battery upright. It is allowed to...
The Renogy Deep Cycle AGM battery is a serious contender for the best solar battery, thanks to its efficiency in multiple circumstances. For starters, it's worth noting the battery is certainly not the lightest and it takes up a fair deal of space. However, it's pretty easy to install and get in operational condition. Furthermore, this specific model is practically maintenance-free.
This solar battery has an impressive capacity of 100Ah/10-hr rate to 10.8 V at 25°C. In simpler terms, this means it charges pretty quickly, holds the charge for quite a long time and is quite energy-efficient -although not as efficient as lithium batteries. The battery also has a 600 cycle 50% DOD rating, a fairly decent rating, especially for an AGM battery.
The battery comes with a canvas case melded with metal-eye holes, making it durable against harsh outdoor conditions. It also features a built-in zipper-closed pocket that safeguards devices while charging. Finally, the Renogy Deep Cycle AGM battery is quite cost-effective, priced quite reasonably for the average consumer.
3. Universal 12V 100Ah Deep Cycle AGM Battery
- UPG #45978 UB121000 12V 100Ah
- Dimensions: 12.17 inches x 6.61 inches x 9.16 inches. Weight: 63.93 Lbs
- SLA/AGM maintenance free, spill proof battery
- Rechargeable battery that can be mounted in any position, resists shocks and...
- 1 Year Warranty
If your idea of the best solar battery is solid and immensely durable, the Universal 12V 100Ah Deep Cycle AGM battery is an excellent choice to consider. First, it's incredibly versatile since you can mount it in any position. This also goes for its installation, which is as easy as it could get.
It comes in a durable shell that's resistant to shock and vibrations, and it also performs quite well in hot and cold temperatures. The Universal UB121000 is also spill-proof, meaning you essentially get a maintenance-free battery. It undoubtedly a reliable power source, especially for critical applications.
This is an affordable and efficient choice, but you'll also have to make some trade-offs. It's quite heavy, and the charging time is about average. That being said, it's a UL recognized & DOT classified solar battery that won't let you down in terms of discharging rate, overall capacity and durability.
4. Mighty Max Deep Cycle Rechargeable Battery
- ML12-12F2 SLA is a 12V 12AH Sealed Lead Acid (SLA) rechargeable maintenance free...
- Dimensions: 5.94 inches x 3.86 inches x 3.98 inches. Terminal: F2. Listing is...
- SLA / AGM spill proof battery has a characteristic of high discharge rate, wide...
- Rechargeable battery that can be mounted in any position, resists shocks and...
- Backed by a 30 day refund policy and full 1 year warranty
If you want a small, affordable battery for your solar panels, the Might Max Deep Cycle is a highly-rated option to consider. For starters, you technically get 2 batteries for a relatively low cost. Despite the notably low price, this battery still performs quite surprisingly well.
It comes with a spill-proof design, is easy to mount and install. This battery delivers a more than decent discharge recovery and works just fine in high and low temperatures. The solid build also means you get a durable solar battery with long service life.
As much as it doesn't exactly match up to the more expensive solar batteries, you still get pretty good value for the price. Since you'll be getting two batteries, the Mighty Max Deep Cycle Rechargeable Battery is worth considering for a budget solar battery storage.
5. WindyNation AGM Deep Cycle Sealed Lead Acid Battery
- WindyNation 100 amp-hour, 12 Volt heavy duty deep cycle AGM sealed lead acid...
- Ideal for all types of off-grid power: Solar Systems, RV's, UPS, Off shore...
- 99.995% pure virgin lead allows for an extremely low discharge rate and maximum...
- Technical and physical specifications can be viewed in the photo gallery (image...
- 100 Amp-Hours at the 10 hour rating. 110 Amp-Hours at the 20 hour rating! 1 year...
This solar battery might be one of the pricier options on this guide, but it's certainly one of the best AGM batteries on the market also. It provides up to 100-Amp hours per 10-hour rating, offering superb energy capacity, great efficiency and impressively low idle discharge rates, thanks to the virgin lead build.
It also features heavy-duty plates that allow for extended repetitive and deep discharges. The extremely low self-discharge rate makes the WindyNation AGM Deep Cycle Battery well-suited for entire off-grid, power supply applications and backup power. On top of its superior performance and longevity, this solar battery also comes backed by a 1-year warranty.
Factors to Consider in the Best Solar Battery
Solar power systems are quite expensive to setup, so you don't want just to walk out and buy any solar battery. If anything, you'll probably be overwhelmed the dozens of options available, not to mention multiple specifications that you have to look into for each product. For this reason, here are some of the key considerations to keep in mind when you're looking for reliable solar battery storage:
1. Battery Capacity
One of the initial things to consider before buying a solar battery is how big it is. This isn't in particular reference to physical size -although you might also have to think about how much space you have available for the setup. Instead, size refers to how much energy the battery can store, thus its capacity.
Battery capacity is measured in Amp-Hour (Ah), which represents the amount of energy the battery can store under specific conditions. For example, a 12 volt 18 Ah battery can produce one hour of 18 amperes of current at 12 volts. Generally speaking, the higher the battery capacity and power rating, the better off the solar power storage.
When looking at battery capacity, there are a few things to keep in mind. One, solar batteries are stackable, allowing you to use multiple batteries simultaneously. Two, a battery with a high power rating and low capacity can run an entire home's solar power system, but only for a couple of hours. On the other hand, a battery with a low power rating and high capacity will only power a few essential appliances, but for an extended period.
2. Round-Trip Efficiency
Round-trip efficiency is a measure of how well an energy storage system (made up of the battery and inverter) converts and stores electricity. Every electrical process loses some of its energy, meaning you'll also lose some kilowatt-hours of electricity when inverting from direct current (DC) to alternating current (AC). The same losses still come into play when you harness electricity in the battery then take it out again. To bring all these home, a battery's round-trip efficiency indicates how many units of electricity you'll draw out of a battery for every unit of electricity that goes in.
3. Charging Time
It's only logical to consider how much sun and time it would take to charge the solar battery. The faster the battery charges, the sooner you can use the solar power, and the less light and time spent.
- If you want the fastest charging, you're probably better off with gel.
- Lithium batteries usually taker around 3 hours or slightly longer.
- Flooded lead-acid batteries take up to an entire day to charge and sometimes even longer.
4. Battery Lifetime: Throughput and Cycles
Battery lifetimes are categorized in three different metrics:
- (Expected) lifespan.
- (Expected) throughput - allows you to compare how much electricity you can move through the battery over its lifetime.
- (Expected) cycles - represents the number of times the battery can charge and discharge.
Generally speaking, the higher any of these metrics, the more you can exploit from your solar energy system.
5. Battery Lifespan
You also have to consider how long the battery will reasonably last. At the same time, you have to keep in mind your battery's ability to hold charge will naturally diminish over time. The decline in performance varies depending on the type of battery, size and reliability. If you want solar batteries that last exceptionally long, you'll certainly have to pay more; but you still have to pay attention to the specific battery ratings.
6. Ease of Installation
You also have to factor in how easy the battery is to install. While it's certainly a process you can learn and do yourself, it's always recommended to let a professional help you with it. That said, if you're looking for a solar battery that's friendly to space, maintenance-free and fairly easy to install, you'll be best-suited buying lithium-ion batteries.
Frequently Asked Questions (FAQs) on Solar Batteries
1. How many solar batteries are usually needed to power a home?
Most homeowners require only two to five solar batteries to power their homes effectively. However, this does vary depending on specific energy needs. As mentioned before, solar batteries are stackable, which means you can install several batteries to get the right capacity for your solar storage system.
You can choose between connecting multiple batteries in a series or a parallel battery bank with interconnecting cables.
2. How long do solar batteries last?
Fully charges solar batteries can typically power a home for 12 to 24 hours, depending on various household factors. The best batteries for solar should last between 10-15 years. It's worth noting that proper maintenance can extend battery life significantly.
3. What is a solar panel battery? -green coast
Basically, this refers to all the components that make up the solar power storage in a solar system:
- Solar panels collect energy from the sun and convert it to DC electricity.
- The battery system allows for solar energy storage.
- The inverter converts DC to AC for consumption.