Traditionally, solar systems have employed deep-cycle, flooded lead-acid batteries for energy storage, because they are durable, cost-effective, and they offer the charging characteristics and performance required for the high demands that solar systems place on batteries.
Flooded Powersonic lead-acid batteries, however, require extensive maintenance to maintain their performance and extend their lifespan. And, because they aren't sealed, they can release large amounts of extremely flammable hydrogen gas during the charging cycle, and they can easily spill sulfuric acid, which is corrosive and can cause serious injuries to exposed skin.
Sealed lead-acid batteries, also known as absorbent glass mat batteries, offer a safer alternative to flooded batteries, because they're completely sealed and the electrolyte is absorbed into fibrous mats, virtually eliminating off-gassing and spills. Power Sonic is one of the largest manufacturers of sealed lead-acid batteries, and they offer a range of capacities that are perfect for energy storage in off-grid solar power systems.
Here are the advantages of using a Power Sonic battery in your solar system.
1) Large Capacities
Solar systems that are not connected to the local electrical grid need large amounts of energy storage to supply power after the sun sets or when the skies are cloudy. This is typically achieved with a large bank of multiple batteries that are connected in a combination of series and parallel circuits, depending on the voltage and amperage requirements of the system. As the number of batteries in a bank increases, so does the potential for electrical losses from faulty connections and long wire runs. By using large-capacity batteries, the losses in the electrical system are minimized.
The Power Sonic battery line is available in capacities from a few amp-hours to over 200 amp-hours, including popular 12-volt models like the 35 Ah, 100 Ah, 210 Ah and 260 Ah. They are also available in 6-volt models, such as the 210 Ah version.
The amp-hour rating reflects the amount of current a battery can provide over a given time. For instance, a 100 Ah battery can theoretically provide 1 amp of current for 100 hours, 10 amps for 10 hours or 20 amps for 5 hours. However, to maximize the life of any type of lead-acid battery, it should never be drained below 50 percent of its total capacity, and in solar applications, it's best to avoid discharging the battery below 70 percent of its total capacity.
2) Long Life Cycles
Several types of lead-acid batteries are common in off-grid solar systems. Inexpensive flooded deep-cycles designed for Marine or recreational vehicle use tend to be dual-purpose batteries designed both for starting and deep-cycle usage, with lead plates that provide high amperage for starting an engine when necessary. Unfortunately, this limits their longevity as deep-cycle batteries, and they tend to have a lifespan of only about three years when used in solar systems. More expensive flooded batteries designed for true deep-cycle performance tend to be very expensive, but they can last from 5 to 7 years with heavy cycling in a solar system. They require frequent maintenance, however.
Sealed lead-acid batteries, such as the Power Sonic battery line, are now cost-competitive with flooded deep-cycle batteries, and often cost significantly less. They can offer over five years of cyclical use in solar systems, and they often last longer when the battery bank is sized appropriately. At a 50 percent depth of discharge, they can provide over 400 charge and discharge cycles, depending on the temperature and other variables. And at 30 percent depth of discharge, or 70 percent remaining capacity, they can offer well over 1000 cycles.
3) Reduced Maintenance
Flooded lead-acid batteries require significant amounts of maintenance to keep them operating properly and to avoid shortening the life of the battery. As they charge, they release hydrogen gas and other compounds, reducing the amount of electrolyte available to the battery over time. To keep the battery operating properly, it must be periodically opened to add water to the existing sulfuric acid electrolyte, a potentially dangerous process that could cause injuries to the person maintaining the batteries. Additionally, the specific gravity of the electrolyte and the battery voltage must be constantly monitored, and the contacts must be cleaned of corrosion periodically.
Sealed lead-acid batteries like the Power Sonic battery line use a valve-regulated design that recombines gases with the electrolyte during the charging cycle. This means that under normal circumstances, a Power Sonic battery will not emit hydrogen gas when recharging, making it safe to use in confined spaces. It will also not leak any electrolyte, as is common with flooded batteries. Because of its sealed design, a Power Sonic battery can be used in nearly any orientation and requires very little maintenance — just periodic voltage monitoring and terminal cleanings.
4) Competitive Costs
Sealed lead-acid batteries are typically more expensive than entry-level marine or RV deep-cycle batteries, but they feature a longer lifespan and require much less maintenance. Compared to high-end flooded deep-cycle batteries specifically designed for cyclical use, however, they are very cost-competitive and are often priced lower. When the overall lifespan and maintenance requirements are considered, sealed lead-acid batteries like the Power Sonic battery series represent a good alternative to traditional flooded lead-acid batteries. And because they are sealed, they offer more flexibility in their placement and use.
Other battery types, such as lithium ion, lithium phosphate or sodium ion, can be used in off-grid solar systems, but they tend to cost far more than either flooded or sealed lead-acid batteries, and are not yet practical for many solar system owners.
With their sealed design, low maintenance, reasonable cost, and large capacities, the Power Sonic battery series can be an affordable and reliable solution for storing energy in your off-grid solar system. They are compatible with most equipment used for charging flooded batteries, and can be installed in series or parallel configurations to match your system's specifications.