4 Ways Lithium Batteries Power Up Solar

Posted September 17, 2018

Lithium Batteries Power Solar PanelsInvesting in solar is smart; pairing solar with a lithium battery storage unit is even smarter. While lithium batteries tend to be a higher initial investment than lead acid batteries, their superior performance and longevity makes them an ideal choice for off-grid and grid-tie applications.

When selecting a battery to complement your solar system, understanding the advantages that lithium batteries have over lead acid batteries is essential. Below are some key advantages:

1) Lithium batteries are efficient.

According to the Institute of Electrical and Electronics Engineers, the efficiency of lead acid batteries is around 70% to 80%. This low efficiency is present throughout the life of the system. In a world where inverters and charge controllers are reaching efficiencies in the high 90s, it is highly desirable that the energy storage system is also highly efficient. This is where lithium batteries exceed lead acid batteries since their efficiency is typically 99%.

Harvesting all the energy from your renewable energy system is another way in which lithium batteries outperform lead acid batteries. The low charge acceptance of lead acid batteries often means that your inverters and charge controllers must reduce the energy that they can harvest so as to not exceed the low charge currents that lead acid batteries can accept. Lithium, on the other hand, does not have such a disadvantage since they can be charged at the 1C rate. For example, if your lithium battery has a capacity of 100 Ampere-hours, you can charge your battery with 100A.

2) Lithium batteries are long lasting.

The cycle life of a battery, defined as a discharge followed by a recharge, is an important parameter in batteries since it determines how long your batteries will last. This is another area where Lithium batteries outperform lead acid batteries since they often last 20 times longer than lead acid batteries. If you discharge your lead acid battery 100% of its capacity it will deliver about 400-600 cycles. A lithium battery on the other hand will deliver 8,000 cycles under the same conditions.

One of the reasons that lead acid batteries do not last as expected is their sensitivity to being undercharged. If a lead acid battery is chronically under-charged, it will suffer significant damage and its life will be reduced by 80%. This is important since renewable energy sources are naturally intermittent with the end result of the batteries being operated at partial states of charge. With lithium, you do not need to worry since cycling lithium batteries at partial states of charge does not harm them in any way.

3) Lithium is cost-effective.

With lead acid batteries you often have to over-size your battery bank to limit how much you discharge your batteries. Most lead acid battery manufacturers do not recommend that you discharge their batteries beyond 50%. This means that your battery bank has to be 2 times bigger than it really needs to be. Lithium batteries allow you to use 100% of their energy without any damage. Thus, removing the need to oversize your battery bank.

Batteries experience a decrease in capacity at low temperatures. This means that the battery bank has to be over-sized to meet the energy requirements of the solar system at low temperatures. Lead acid batteries are significantly affected by low temperatures whereas lithium batteries are not.

4) Lithium is zero maintenance.

Lead acid batteries need to be carefully monitored and maintained; if water levels drop too low, you have to refill them or face significant damage and hazard risk. Lithium batteries, conversely, require zero maintenance after installation. While you should monitor any battery you purchase – even lithium – upkeep is reduced significantly with a lithium-based solution.

Lithium batteries are also very space-efficient. If you’re setting up your solar application and find yourself running out of room for batteries, choose lithium to reduce your size constraints considerably.

Compared to lead acid, lithium offers a more compelling energy storage option in nearly every situation. If you’re unsure about your solar power storage needs, contact us so we can help determine the perfect fit for your application.

Interested in more? Get all the technical specifications you need to find the right lithium solar battery for your application.



  • Joseph Taylor