Comparing Lithium-ion VS Lead-Acid Batteries: Which one is the Best?

Both lithium-ion and lead-acid batteries can effectively store energy, but each has different advantages and disadvantages. Here are some key comparison points to keep in mind when selecting a battery type:

• Cost of the Battery
• Battery Storage Capacity
• Battery Efficiency
• Charging Rate of the Battery
• Battery Energy Density

·         Cost of the Battery

The one area where lead-acid batteries appear to outperform lithium-ion options is cost. A lead-acid battery system may cost hundreds or thousands of dollars less than a comparable-sized lithium-ion setup.

On the other side, lithium-ion batteries currently cost anywhere from $5,000 to $15,000 including installation, and this range can vary depending on the size of the system you require.

While lead-acid batteries typically have lower purchase and installation costs than lithium-ion options, the lifetime value of a lithium-ion battery balances the scales. 

·         Battery Storage Capacity

The capacity of a battery is a measure of how much energy it can store (and eventually discharge). While capacity numbers vary depending on the battery model and manufacturer, lithium-ion battery technology has been shown to have significantly higher energy density than lead-acid batteries. 

This means that a lithium-ion battery can store more energy in the same physical space. Because lithium-ion technology can store more energy, it can discharge more energy, allowing you to power more appliances for longer periods.

·         Battery Efficiency

Battery efficiency, like solar panel efficiency, is an important metric to consider when comparing different options. Most lithium-ion batteries are 95 percent efficient or higher. This means that you can use 95 percent or more of the energy stored in a lithium-ion battery.

 Lead-acid batteries, on the other hand, have efficiencies of 80 to 85 percent. Higher efficiency batteries charge faster, and improved efficiency, like depth of discharge, means a larger effective battery capacity.

·         Charging Rate of the Battery

Higher efficiency means a faster charge rate for lithium batteries. They can resist high amperage from the charger, allowing them to be refilled much faster than lead-acid batteries.

 Primarily, Lead-acid batteries contain limited  amount of charge current they can handle. This is because they overheat if charged too quickly. Furthermore, as you approach full capacity, the charge rate slows significantly.

During the bulk phase, lead-acid batteries can charge around C/5 (up to 85 percent capacity). The battery charger then automatically slows down to top off the batteries. This means that lead-acid batteries take longer to charge, sometimes more than twice as long as lithium batteries.

·         Battery Energy Density

Lithium batteries have a much higher energy density than lead-acid batteries. It means they can fit more storage capacity into less space.

Although most installers can handle the extra weight. But, DIYers may find lithium batteries more difficult to install. It’s a good idea to get some help lifting and moving them into place.

If you need to get creative with how you mount your battery bank, this is a big help. If you are mounting an enclosure on the wall or concealing it in a closet. The more energy density allows your lithium battery bank to fit into smaller spaces.

Lithium-ion VS Lead-Acid Batteries: Which one is the Best?

Although, Lead-acid and lithium-ion batteries are both viable options for battery backup systems. However, because of the many advantages of lithium-ion technology, such as a longer lifetime, higher efficiencies, and higher energy density, installing one is usually the best choice. Despite their higher initial costs, lithium-ion batteries are typically more valuable than lead-acid alternatives.