Choosing the Right Maintenance Free Solar Battery
Need reliable, low maintenance deep cycle batteries for your solar, wind or emergency backup system, but aren’t sure which technology is best? We understand choosing the right maintenance free solar battery can be confusing. Fire Mountain Solar usually recommends two types. The one that is best for you will depend on your goals, how you will be using your system, and your budget.
Option 1: SLA (Sealed Lead Acid) – AGM (Absorbed Glass Mat) or Gel Batteries
Details: with AGM batteries you can use up to 50% of the rated capacity (depth of discharge aka DoD) if you want the longest life out of your storage system. This is approximately 1,300 cycles, or 3.5 years if you are cycling your batteries daily.
A sealed lead acid-based technology that requires limited maintenance and has been an industry standard for over a decade. Specifically designed for deep-cycle solar powered applications, these batteries provide a cost-effective choice for energy storage.
Gel batteries have lower charge rates and output, as well as lower threshold for charge current than AGM batteries. This means they take longer to charge and output less power overall.
Option 2: Lithium Batteries
Lithium Ion batteries are some of the most commonly used in the world. These are the same batteries that come in cell phones, laptops, and all sorts of electronics. With some modification, this kind of battery can be used for home energy storage. Many high-profile home storage options (such as the Tesla Powerwall) are Lithium-Ion based.
Details: Lighter and more compact than SLA batteries. They also have a higher depth of discharge and longer lifespan. Generally warrantied and effective from 4-10 years. More expensive than SLA batteries. With Lithium Ion batteries there is the danger of thermal runaway (uncontrolled overheating) if the battery experiences damage (from external force, internal chemistry issues, or over/undercharging).
Due to the potential risk associated with Lithium Ion batteries, Fire Mountain Solar does not sell them for home energy storage use.
LiFePO4 (Lithium Iron Phosphate)
Lithium Iron phosphate is a high-performance chemistry that allows for deep cycling of batteries, meaning more energy is available at every rating. LiFePO4 batteries can function with little maintenance for upwards of two decades. LiFePO4 is a lithium technology that provides protection from thermal runaway.
Details: With LiFePO4 you can use up to 80% of the rated capacity and still get the maximum lifespan from your system. This is approximately 8,000 cycles, or roughly 21 years if cycled daily.
LiFePO4 battery systems are premium in performance, durability, and price.
Which Maintenance Free Solar Battery is Right for You?
If you are okay with replacing your batteries more frequently and purchasing a larger battery bank, SLA batteries may be right for you. If you have less space to install your batteries or simply do not want to replace your batteries every few years, a LiFePO4 system may be best for you.