The home storage revolution has arrived, and you have various home battery choices to choose from. We may discuss battery power in this article, including what it is, why it matters (or doesn’t), and how different battery models compare.
- The home batteries with the most energy are currently made by Eguana, Electric Power, and Sonnen.
- Battery capacity can be misleading; in many situations, you can stack several batteries to create a more extensive system.
What is Battery Capacity, and how is it measured?
As battery capacity (also called energy capacity) is mentioned by manufacturers and installers, they typically speak about one of two metrics on which a battery is rated: overall capacity and usability. We will get into why they are different a little later. It is all about “capacity” for the time being.At its core, the battery capacity means precisely the energy in a home battery in kilowatt-hours (kWh). From our glossary of key energy storage terms to know, here’s a more detailed description of energy capacity:A storage system’s energy capacity is measured in kilowatt-hours (kWh), reflecting the amount of time it can power your appliances. Energy is calculated by multiplying power consumption by time: kilowatts multiplied by hours equals kilowatt-hours. To consider battery energy sizing, you must first determine how long you want to operate your appliances on the battery. From a power and energy (capacity) perspective, running more devices for a long time would necessitate a larger battery, while running fewer appliances for a shorter time would require a smaller battery.Ten CFL light bulbs on for six hours consume almost one kilowatt-hour of electricity (10 CFLs * 15 Watts per bulb * six hours) to explain how much different energy appliances use. Depending on how often the TV is switched on and off and what temperature the refrigerator is set at, television or refrigerator will use 1 kilowatt-hour of energy in 24 hours. On the other hand, running a central air conditioner will consume up to 10 kilowatt-hours per day.
Total capacity vs. usable capacity
A battery’s power is assessed in two ways: total capacity and usable capacity. We prefer to measure storage devices using functional capacity as the main “capacity” metric since it is most applicable to the amount of electricity you can get from a battery.
See how the two words vary below, courtesy of our energy storage glossary:
Total capacity (kWh)
When fully charged, how much electricity is stored in the battery? Expressed in kilowatt-hours, this is an energy statistic that shows the amount of power required if you could completely discharge your batteries to zero.
Usable capacity (kWh)
The amount of electricity in the battery that can be used. The native load requirements of batteries are different. To put it another way, batteries take a certain amount of electricity to keep running. As a result, you may not be able to use all of the energy contained in a battery. If you want to use a battery’s available power outside its capacity, it could damage its health and longevity.
Why capacity matters?
The more energy it can store, much like any other battery, the more things it can typically power. Of course, other considerations (such as power rating and chemistry) come into play, but in general, more energy means you can operate more devices over long periods.When it comes to home batteries, this ensures that a bigger battery would provide you with enough electricity over a more extended period if the grid goes down. It also ensures that if you are using your home battery to avoid buying electricity at peak, costly hours (such as in an area with TOU rates), you will draw from your battery for more extended periods and avoid the high-cost block altogether. Increasing battery capacity is a great way to make sure you are getting the most out of your storage unit, particularly if you are charging it with solar panels during the day.
The only caveat is those home batteries can (often) be stacked.
Battery capacity is essential, but it is also crucial to remember that the power of a single battery is not always the energy you will need. You can connect several Tesla Powerwall batteries, for example, to produce a several times larger system than a single battery. If limited space is available, the battery capacity will be more critical in a single product. To store enough electricity for homes with high electric bills, you will almost always need to add a stacked battery pack.
The most potent batteries: a comparison of the best brands
Individual battery capacity is only essential to an extent, but it can be a significant factor. Below is a table listing the largest battery from each of the most common home battery brands, rated from highest to lowest capacity:The Biggest home batteries: Ranked by capacityAs previously stated, the capacity of a single battery is not always representative of battery-to-battery comparisons. Although the Tesla Powerwall is one of the most miniature batteries on this list, it is one of the most popular. It is critical to choose a home battery that meets your needs in terms of functionality and performance since you can combine most devices to produce larger battery banks.