When it comes to generating solar power on a household scale, there’s really no way to get around the humble battery that will serve as storage for the energy you draw from the sun’s rays. Even if you install the highest quality monocrystalline solar panels and advanced inverters, your system is really only as useful as your battery bank will allow it to be. While you can certainly generate power without sufficient storage, you won’t be able to store it for use when the sun isn’t shining. For that reason, solar battery systems are a key consideration when you design your solar power generating system.

Solar Panels on Roof

Battery systems for solar can come in many configurations, but two of the most popular types are the standard lead-acid batteries common in automobiles and lithium-ion batteries. Though both can admirably perform in a solar power generation context, each has its advantages and liabilities. Keep reading below to learn more about the differences that separate modern lithium-ion batteries from there more traditional lead-acid counterparts.


What Are Lead-Acid and Lithium-Ion Batteries?

Before we can understand the differences in their storage characteristics, we must first understand what constitutes a lead-acid battery and a lithium-ion battery. Lead-acid batteries have been around for well over a century, and they come in two primary types. The oldest type involves thin sheets of lead submerged in a weak sulfuric acid. Newer types of lead-acid batteries substitute a gel substrate in place of the liquid acid. A lithium-ion battery involves cells featuring a lithium-cobalt or lithium-iron-phosphate electrode paired with a graphite electrode connected with an electrolyte substance. Power is stored and discharged by the transfer of lithium-ions between the electrodes.



When it comes to cost, the clear advantage goes to lead-acid batteries. The older technology, invented in the mid-19th century, is cheap to manufacture and widely available in the automotive industry. Lead-acid batteries are easy to obtain at a low price point, which makes them an attractive option for anyone who is building a solar system on a budget. You can afford to buy several lead-acid batteries for the price of a lithium battery, though it should be noted several lead-acid batteries may likewise be needed to match the performance of a single lithium-ion battery.



There’s a reason that lithium-ion batteries are most expensive than their lead-acid counterparts, and that’s because they have superior performance characteristics. For example, lithium-ion batteries have significantly more storage capacity when compared to lead-acid batteries. Though specific capacity differs from battery to battery, lithium-ion batteries are known to have a higher energy density, which translates to more capacity to store energy.


Depth of Discharge

While capacity is certainly an important measurable, equally critical when considering battery types for solar systems is the depth of discharge. After all, capacity becomes a moot point if the battery can only be discharged to 50 percent without causing damage. Lithium-ion batteries are also superior to lead-acid batteries in this regard. The typical lead-acid battery can only be discharged to 50 percent before damaging the battery, while lithium-ion batteries boast a depth of discharge rating that can approach 85 percent with no ill effect.



Again, lithium-ion batteries get the nod when it comes to efficiency, as they can perform much more favorably than the traditional lead-acid battery. Most quality lithium batteries are rated at 95 percent efficiency, which means all but five percent of the energy stored is available for use. For lead-acid batteries, that efficiency rating falls to around 80 percent, making lithium-ion batteries the clear winner in this regard.

Whether you choose a lithium-ion or lead-acid deep cycle battery to support your solar power storage needs, it’s important to understand the differences in the two technologies as well as their strengths and weaknesses. To learn more about the differences between lithium-ion and lead-acid batteries, contact The PowerStore Inc. at (888) 595-0580.