What are the best solar batteries on the market in 2020?

Without a battery bank, you won’t be able to store energy generated by your system. If you’re tied to the grid, no battery means no backup power when the utility grid suffers an outage. If you live off-grid, your system simply won’t work at all.

Batteries are crucial to keep your system running. So what are the best solar batteries on the market?

Since you’re busy, we’ll put our recommendations up front. Keep reading for a breakdown on where each battery shines:

Best Overall Battery for Off-Grid Homes

Best Value Battery for
Off-Grid Homes

Best Battery for
Off-Grid Vacation Homes

Best Battery Backup for Grid-Tied Systems

Best Battery for Storing and Reselling Energy

Best Battery for RV, Marine, Small Off-Grid

What Are The Different Types Of Batteries?

To understand why we chose the above batteries, let’s review what the different types of batteries are. When selecting a battery for your solar system, you have three options: flooded lead-acid, sealed lead-acid, and lithium batteries.

Flooded Lead Acid Batteries

Lead-acid batteries have been used for the last 150 years. These batteries are affordable and about 99% recyclable. They are easy to get rid of at the end of their lifespan.

There are two types of lead-acid batteries: flooded and sealed.

Flooded lead-acid (FLA) batteries are designed to handle daily charge cycling. They do emit gas as a byproduct, so they must be ventilated properly.

FREE Solar Battery Guide

They also require regular maintenance. The plates of every cell in the battery must be submerged in water to function properly (which is why they are called “flooded” batteries). You’ll need to add water every 1 to 3 months to keep the plates submerged. It’s smart to check on them once a month.

FLA batteries are ideal for people who prefer to be hands-on with their system. They’re the most affordable option, but require occasional upkeep to work properly.

Sealed Lead-Acid Batteries

If you won’t be around to perform regular check-ups on your battery, sealed lead-acid batteries are a better option. These batteries are spill-proof and non-hazardous. There are two types of sealed lead-acid batteries with fairly similar characteristics: AGM (absorbent glass mat) and gel.

Sealed batteries are a self-contained system. They don’t need to be refilled with water, like flooded batteries. For that reason, they work well at properties that aren’t occupied full-time, like an off-grid vacation cabin you visit once or twice a year. Sealed batteries won’t self-discharge as fast if they sit idle for extended periods of time while you’re away.

Lithium Batteries

Finally, lithium batteries are a newer technology that hit the market in the 1970s. They are common in laptops and cellphones, but have become more popular in the renewable energy space lately.

Lithium batteries are more expensive, but there are several benefits to justify the higher price tag:

  • Longer lifespan
  • No maintenance
  • More efficient power usage
  • More usable storage capacity (deeper discharges)
  • No off-gassing / ventilation

Best Solar Batteries of 2019: Our Recommendations

So what’s the best battery for your system?

Picking the right battery depends on a combination of factors like application, budget, and expectations for upkeep (like regular maintenance and replacement interval). Your living situation will determine the smartest battery choice for your project.

Here’s our breakdown of the best batteries for a wide variety of situations:

Best Battery for Off-Grid Homes (Overall)

If you live in an off-grid home full time, you need a battery that can keep up with your power demands on a daily basis.

Our recommendation for the best overall battery for off-grid homes is the Discover 48V Lithium battery. It has a long lifespan and affords flexibility if you want to expand your system down the road.

Lithium batteries are a premium storage option. They have a longer lifespan and charge faster than other battery types. And because they can handle deeper discharges, you need less overall capacity than you would with a comparable lead acid battery bank.

They also make it easier to expand your system over time. Let’s say you add a new well pump to your property down the line. With lead-acid batteries, it can be difficult or even impossible to expand your battery bank, depending on the age and how they are wired.

That’s not the case with lithium batteries. More batteries can be added over time, because each battery operates independently with its own internal Battery Management System (BMS).

Lithium batteries can handle extended periods of time without being recharged. This situation would actually damage lead acid batteries because they need to be recharged every day, and will be damaged after several days without a full charge.

That’s why the Discover 48V Lithium battery is our pick for the best overall battery for daily off-grid use.

Best Battery for Off-Grid Homes (Best Value)

Looking for a more cost-effective option? The best value battery for off-grid systems is the Crown CR430 flooded lead-acid battery.

People who live the off-grid lifestyle tend to be more comfortable with hands-on DIY projects. If you don’t mind doing the occasional tune-up on your battery bank, the CR430 is an excellent option.

The 430 amp-hour capacity can’t be beat for the price, and Crown is a reliable American manufacturer (they show up on this list 4 times for a reason). CR430s are built in Fremont, Ohio at Crown’s advanced manufacturing plant.

Best Battery For Off-Grid Vacation Homes

What if you have an off-grid vacation home that you don’t visit on a regular basis? You want a battery that doesn’t require regular maintenance, since you’ll only be on site a few times a year.

In these cases, a sealed AGM battery is the best option. Our recommendation is the 415Ah FullRiver DC400-6. The lower capacity is fine because you don’t need year-round storage. We also skipped out on the premium lithium option, because it’s overkill for a system that will only be used a few times a year.

These batteries are relatively inexpensive, so you don’t have to make a huge investment into a property where you won’t be spending that much time.

The Best Batteries For Living Grid-Tied With Battery Backup

If you have a grid-tied system with battery backup for emergencies, you won’t need a battery with a tremendous amount of storage power. It will only see use when your power goes out, and hopefully that doesn’t happen more than once a year.

Similar to the previous section, you want a battery that doesn’t require maintenance – it should simply work in the rare cases you need it. For that reason, we recommend the same battery as above: the FullRiver DC400-6 with a sealed AGM.

Best Battery For Storing & Selling Energy

In certain areas, the utility company charges more during peak use times – around 4 to 9 pm, when people get home from school and work.

Energy storage allows you to store daytime energy and sell it back to the utility company for a profit.

The goal is to store energy generated during the day, and sell it back in the evening, when rates hit their peak.

For this type of use, we recommend the Discover AES 7.4kWh or the SimpliPhi 3.5 kWh batteries. Both are 48V lithium options. We recommend lithium here because the battery will be cycled more heavily than in a vacation home or battery backup application. The lithium option will have a much longer lifespan and can be just as cost-effective as lead-acid batteries in terms of cost-per-cycle over the life of the battery.

This setup helps protect you from future changes in your utility rates, and is a must if you live in an area with time of use rates (TOU), high demand charges, or no net metering.

The Best Batteries For RV, Marine, Remote Industrial & Small Off-Grid Use

This article has mostly covered residential use cases. But what if you need to power a smaller application, like an RV, boat or small outbuilding on your property?

Let’s say you have a wood shed on your property and want to power it independently. The shed has some lights and wall outlets, but there’s not much else to power. In a situation like this, you just need a compact battery with modest capacity.

For a light use cases like these, we recommend the Crown 6CRV220 sealed AGM battery. This battery was originally designed to power golf carts. As a result, it has a very low profile, but can still withstand deep cycling over a long lifespan.

We’d recommend this battery for tiny homes, boats, and RVs – any application where space is at a premium and you just need to power the essentials. You can also go with the Crown 12CRV110, which is the exact same size and overall capacity.

Battery Math:

The 6CRV220 and 12CRV110 have the exact same size and overall capacity.

6 Volts x 220 amp hours = 1320 watt hours

12 volts x 110 amp hours = 1320 watt hours

This is also our pick for remote industrial applications. It can power small-scale industrial equipment in remote areas not accessible by power lines. Common applications include lighting, pumps, traffic signs and monitoring equipment.

No matter what kind of off-grid system you’re looking for, your battery bank is a key component. Visit our deep cycle battery page to learn more, or check out our battery banks to find a pre-packaged solution.

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