The use of solar panels and solar energy has grown increasingly more common in recent years. Someone doesn’t need to be living “off the grid” to have an interest in energy storage and solar batteries. Many people have chosen to add solar power to their grid-connected homes, providing a backup for emergencies and unexpected power outages, and for having an alternative for everyday use. In many cases, use of solar power reduces energy bills and allows for other money-saving benefits consumers can take advantage of.
However, in order to make the most of the opportunities provided by solar power, you need to find a battery that meets your demands—one that allows for heavy cycling, and irregular full recharging. There are plenty of options and narrowing down your choices will require some research.
What Types of Solar Batteries are Available?
The first step to choosing the best solar battery for your solar panels/solar power system and charge controller is to figure out which type of battery will best suit your needs. There are pros and cons for each type of battery and, in many instances, “the best” is just a matter of figuring out which will work for you.
Different battery types include:
This type of battery has been used by people who chose to go off-grid for some time. They are a cost-effective option and newer models can allow for deep cycling. You can get lead-acid batteries in both absorbed glass mat and gel model. They are built for both dual purpose and standby applications, and the newer AGM designs allow for deep cycling for a lower price than their gel counterparts.
Users love these batteries because they are affordable and they charge faster and cycle more than older traditional lead-acid options. They also don’t require much maintenance because they internally convert hydrogen and oxygen into water. They can also be installed in just about any position, though not upside down, so if you need a battery in a hard-to-reach place that doesn’t need replacing very often, this is an excellent choice.
Lead-acid batteries can be toxic if not disposed of correctly, so when you need to do a replacement, you’ll need to find a way to properly dispose of the used battery.
This is the most commonly used type of battery. There are three different kinds, including pouches, cylindrical, and prismatic. You’ll find this type of battery in a variety of applications, including cell phones and other mobile communication devices, and electric vehicles.
They aren’t as cost-effective as lead-acid batteries, due in part to needing a battery management system to monitor the temperature and voltage of the cells.
In most cases, lithium-ion batteries are able to cycle any more than lead-acid batteries, making them an option for ancillary power sources. Lithium-ion batteries also have a high charge and discharge, which means it’s able to harvest higher levels of energy.
Inorganic lithium-ion batteries can be toxic and difficult to dispose of, but ones with organic cells have no toxins.
Flow batteries are becoming more popular, especially for long-duration use. Most use a mixture of positive and negative electrolyte liquids to operate. They operate in a similar fashion to lead-acid batteries but are more reliable because of the exchange of fluids that produce electrical current without degradation of the membrane. This means they last longer and have a quicker response time than their counterparts.
They are also cost-effective, at least when you consider the lifetime of the battery. They require little maintenance and their life can be extended by adding more electrolytes. They reportedly have no cycle limitations and can be charged and discharged over time without affecting their overall lifespan. They are also easy to dispose of and the electrolyte in these batteries can sometimes be recycled.
Nickel-cadmium batteries have been in use for more than 100 years and offer a long lifespan and are a reliable, simple option. They are relatively inexpensive and the most updated designs allow gas to recombine into the water so the batteries are practically maintenance-free.
Nickel-cadmium batteries can stand up to extreme temperatures, making them a popular choice with off-grid people living in harsh climates. They have a high cycle life and, in some cases, can last up to two decades.
The disposal can be tricky because cadmium is a toxic material. It can be extracted and recycled into new batteries and the nickel can be used to make stainless steel.
What to Consider When Buying a Solar Battery
In addition to knowing what type of battery is going to work best for your system, there are a few other things you’ll want to consider.
- Make sure you choose the right size battery to suit your needs. A size calculator can help you determine your power needs and guide you to the right-sized battery.
- In addition to the price of the battery, you’ll want to consider the overall cost of ownership. The cheapest battery to purchase isn’t always the cheapest over the course of its life. Think about how often you’ll need to replace the battery and consider voltage, capacity, and cycle life.
- Remember that battery ratings can be misleading. Some take up to 100 or more cycles to reach full capacity, and those that reach full capacity sooner than that won’t last as long.
- Try checking the reviews of batteries. The best way to learn if a battery might be the right one for you is to see what users have had to say about it. Chances are the best batteries are going to have solid reviews from people who have experience with solar power.
- Finally, try trial and error—as long as you don’t feel as if you’ll be spending too much money. You can get a feel for the quality of a battery just by investing in a small quantity of them and seeing how they perform.
There are plenty of options available for solar batteries, but five of our favorite choices include: