A battery bank can be an excellent addition to your solar power setup. They provide you with essential energy storage so that you can tap into the excess solar energy that your array generates during the day. But there are several different battery types available for solar systems. Which kind is the best? This blog will compare the 2 most popular battery types: lead-acid and Simpliphi lithium batteries.
Depth of Charge
First, when considering how much power you’re going to get from your batteries, it’s important to consider more than just the battery’s total storage capacity. Solar batteries can’t actually discharge the full amount of their stored energy, so you’ll need to also consider the battery’s depth of charge. Lead-acid batteries typically have a depth of charge of roughly 50%. Lithium batteries, however, have a depth of charge of 80% to 90%. So, even if the battery banks have the same storage capacity, you’ll actually get a lot more power from lithium batteries, because it offers a deeper discharge capacity.
Number of Batteries Needed
Due to their lower depth of charge, you’re probably going to need more lead-acid batteries than lithium batteries to build battery banks of the same size. This is important to consider when calculating both the total cost and the total amount of space you’ll need for your battery bank.
Battery Size
If space or weight is an important consideration for your battery bank, then you’ll probably want lithium batteries. These tend to be smaller and lighter than their lead-acid counterparts. First of all, you’ll probably need more lead-acid batteries to build your bank, as mentioned above. That alone means more space and more weight. But the batteries themselves are also larger. For a standard off-grid battery bank, you’ll be looking at almost 1,000 pounds of batteries for a lead-acid battery bank, while a lithium battery bank of the same size would weigh under 400 pounds.
Battery Life
Lithium batteries have a much longer life than lead-acid ones. This is reflected in the warranty that comes with them. Most lead-acid batteries only have a 3-year warranty, while lithium batteries often come with a 10-year warranty. With a shorter battery life, you’ll need to factor replacements into the total cost of your lead-acid battery bank.
Cost
Of course, the total cost is an important consideration for any homeowner. While the upfront cost of lithium batteries is significantly higher than lead-acid ones, their longer battery life and deeper discharge (which equates to higher efficiency) typically make it the better choice in the long run.
If you’re shopping for batteries for your solar setup, Simpliphi lithium batteries are the best option for solar battery storage.
