Whole House Battery Backup – FAQ’s

What is a battery?

A battery is a container that stores electrical energy.

How much do batteries cost?

The price for a bank (set) of batteries for the storage of solar typically ranges from $800 to $25,000. Your cost will depend on what you will be powering, and for how long you want to go before having to recharge again.

Why would I want a battery?

Whole house battery backup keep your refrigerators, electric vehicles, lights, well pumps, and more operating silently, without running a noisy generator. When grid power fails, transition between grid power and battery power is automatic, silent, and reliable.

Do I have to have solar with batteries?

No, having batteries does not mean you must have solar. You can get an emergency battery backup system that is kept charged by the grid until you need it. Then the grid can recharge the batteries when it becomes available again. Or you can use a backup generator to charge the batteries should your utility be down for an extended period of time. NOTE: A solar and battery backup system qualifies for the federal income tax incentive, a battery-only system does not.

What is the expected life span of a battery?

When properly cared for, batteries can last from 2-20 years, depending on the quality of the battery and how well it is maintained. As a battery owner, it’s important to understand the basics of system maintenance. Providing proper maintenance to the system will ensure maximum life expectancy of your batteries. Even maintenance free batteries would benefit from you checking every few months that the battery terminal cable connections are tight.

Where do I put them?

It’s imperative that batteries are not exposed to the outside elements. Ideally, a battery bank should be in your basement, garage, shop, or some type of shed where the temperature range is controlled.

What types of batteries are available and which is best for my situation?

The type of battery technology depends upon your intended use:

  • Sealed Lead Acid are ideal for grid tie battery backup because they are essentially maintenance free and are designed to effectively sit at a full state of charge for most of their life.
  • Flooded Lead Acid is better for off grid applications because they can withstand frequent charging and discharging (cycling).
  • Lithium is a technology unlike other batteries; they can be discharged to 0% without having any damaging effects, whereas discharging a lead acid battery more than 50% can cause damage. Lithium batteries are best suited for grid tie battery backup for large residential or small commercial applications. The initial cost of lithium batteries can be expensive, but with the number of years they will last and the fact that 100% of the capacity can be used, the difference in total life cycle cost between lithium and other types of batteries is not as significant. The supply of lithium batteries can be inconsistent and there may a long lead time for this product.
  • NanoCarbon is better for off grid users where the charging source may be undersized. They can withstand frequent and extended periods of a partial state of charge without being damaged.
  • Nickel Iron is ideal for both off grid and grid tied applications where budget is not an issue. These batteries will often last over 20 years.