While solar battery storage is only necessary for an off-grid solar setup, many on-grid solar users choose to add a battery bank to their system. This choice enables them to further reduce their dependence on the grid, leading to even lower monthly power costs and the ability to keep the lights on when the grid goes down. If you’re considering adding a solar battery bank to your system, it’s important that you know what to look for before you buy. Keep reading to learn the four main factors that you should consider when shopping for solar batteries.



The first thing you should look at when buying a solar battery is its capacity. This, as you can probably guess, refers to how much energy can be stored in the battery. Some people also refer to this as the battery’s “size,” though this can be confusing, as batteries may be the same physical size but have different capacities. When buying batteries for a backup system, you need to ensure that you’re purchasing enough total capacity to meet your energy needs.

A solar professional can help you to calculate your exact power storage needs if you’re not sure how to do this. However, if you already have a solar setup, the sizing used to calculate your solar array’s size can also be used to calculate your battery bank’s capacity.


solar power battery storage

Depth of Discharge

What many people don’t realize is that batteries can’t actually use the full capacity of their stored energy. They must retain a certain percentage of charge at all times or else risk damage to the battery. Different batteries have different depths of discharge—the amount of power that they can actually use. Make sure to consider the battery’s depth of discharge when calculating your needs, too, so that you know how much usable energy you’ll actually have.


Cycle Life

Cycle life refers to how many times a battery can charge and discharge before it begins to lose its efficiency. The longer the battery’s guaranteed cycle life, the more usage you’ll get out of it before you have to replace it. This is a very important consideration to keep in mind when looking at the last factor in this list.



Finally, consider the battery’s price—but not just the price tag. What you should be looking at is the cost per watt that you’ll be getting from your batteries. This number takes into account the efficiency and lifespan of the battery to help you better determine which battery will give you the most usage for your money. In many cases, a battery that has a slightly higher number on the price tag can actually cost you significantly less in the long run because it lasts longer, is more efficient, and has a deeper depth of discharge.


If you keep all 4 of these factors in mind, you can find the best solar battery for your solar setup. If you have questions about finding a battery bank that meets your needs, contact The PowerStore, Inc., today.