Installing a solar power system can help you become more independent with your energy production, but if you truly want to achieve energy independence, you’ll need a backup power source. Most solar users turn to solar battery storage to build battery banks that store excess solar power produced during the day so that they can use that power at night. If you want to build a battery bank, you must know how to choose the right one instead of alone relying on the price tag. Here’s how to choose the best solar battery for your system.
Determining Your Priorities
The best battery for you is going to depend largely on your priorities. Do you want a battery that can supply power to more appliances at once? Do you need one that can run an energy-intensive appliance? Do you want one that will last for years? Here are a few priorities to consider and what you should be looking for to meet those priorities.
Powering Your Whole Home
If you don’t want to reduce the number of appliances you’re running when you switch to battery power, you’ll need something that can supply sufficient energy to run your entire home. For this, you’ll want to look at batteries with a high continuous power rating.
Powering an Energy-Intensive Appliance
Certain appliances require a large surge of power to kick on. One good example is a sump pump. Suppose you have such an appliance in your home, and you want it to remain operational on battery power. In that case, you’ll need to look at a different power rating when buying a battery: the instantaneous power rating. Look for a high rating in this area to meet those needs.
Powering Your Home for Longer
If you want a long, steady supply of energy to your home when on battery power, you’ll need a battery that has more usable storage capacity. It is called the depth of discharge, or DoD, and is expressed as a percentage. Most batteries cannot empty their stored energy without causing damage to themselves. The higher the percentage for DoD, the more energy they can expel, giving you more usable energy.
Minimizing Lost Energy
All batteries will lose a tiny bit of energy through the simple process of storing that power. As the electricity moves to the battery, is stored there and is pushed out again, some power will be lost. However, some batteries are more efficient than others. If you want to get the most out of every kilowatt you store, look for a battery with a high roundtrip efficiency.
Keeping the Same Battery for Longer
A battery that will continue to work efficiently for years can minimize your overall cost-per-watt on your battery bank. If you want something that will last, look for lithium iron phosphate (LFP) batteries. These have the longest lifecycles of any home solar battery available.