What is a Solar Panel Battery?

what is a solar panel battery

In this blog, we’re going to take the guesswork out of solar panel batteries. There are a lot of considerations, but whether you’ve already gone solar or are planning on it, adding a battery to your solar array could be something you don’t want to pass up.

But… what is a solar panel battery, and why do you need one?

We’re going to break it all down for you in this blog.

So if getting closer to a $0 power bill, power consistency during the night and natural disasters, and near-complete grid independence are things you’re wanting, then keep scrolling.

What is a Solar Panel Battery?

A solar panel battery is a battery for your solar panels! Just like the battery in your phone, it can store power to use at a later time.

Why do solar panels need batteries?

There are times when your panels may produce more power than what your home actually uses. Where does that power go?

There are two possible options: back to the power company through a program called Net Metering, or it could be saved and used by you at night or during power outages or natural disasters via a backup battery.

While net metering can credit your account with your utility company, you’re still “technically” paying for the power your home consumes at night and during storms or outages.

Solar batteries, on the other hand, will retain the surplus power your solar panels produce, so you can seamlessly switch between your solar array to your battery when the sun goes down or when nature strikes.

Store Unused Energy, Save Money, and Protect Your Home

To put it simply, homeowners like you want to feel protected from rising electricity costs and natural disasters – that’s why they’re adding a battery to their solar systems.

Get Your Solar Panel Battery Quote

How Solar Panel Batteries Work

It’s rather simple: the sun shines. Your panels turn the sun’s rays into usable power. You power your home appliances and HVAC with said power. If you don’t use it all — the remainder goes into your battery for later. Easy peasy.

So when the sun goes down later in the day, instead of having to pull from the electricity grid, you can still use clean solar power stored by your solar battery. You will be able to enjoy free, green power any time of day thanks to your solar storage system.

How the Enphase Encharge battery works.

Benefits of a Solar Panel Battery

Why would you want a solar panel battery? Here are just a few of the benefits:

  • Lower electric bill
  • Protection from power outages
  • Maximize the energy from your solar panels

Solar Panel Battery Benefits


Put Your Money Where Your …Power…Is

So, there’s a thing out there known as the ITC, or the Federal Investment Tax Credit, a.k.a. the solar tax credit. It’s a tax credit from the government that could reduce the cost of both your solar array and your backup batteries by 30%*.

With this credit, you could receive a dollar-for-dollar reduction in the income taxes you would have to pay the government. The good news is if you don’t use all of the credit in the first year, the remainder just rolls over to the next.**

Couple that credit with the near-immediate savings you’ll have from your solar panels, and you’ll have a nice chunk of change back in your piggy bank!

Which Solar Batteries to Buy

The best types of batteries for your solar panels should be lithium-ion batteries, which are the safest and most reliable solar batteries available. Let’s go over a couple of our expertly-provided and certifiably-installed solar batteries at ADT Solar: the Tesla Powerwall 2 and the recently released Enphase Encharge.

Read more: Enphase Encharge vs. Tesla Powerwall 2

Enphase Encharge solar panel batteryEnphase Encharge 10:

The Encharge 10™ all-in-one AC-coupled storage system, comprised of three base Encharge 3™ storage units, provides a total usable energy capacity of 10.1kWh and twelve embedded grid-forming microinverters. Connect multiple Encharge 10 storage systems to maximize backup potential for whole home backup.

Read: Introducing Enphase Encharge

Tesla Powerwall 2:

Powerwall is a battery that stores energy, detects outages and automatically becomes your home’s energy source when the grid goes down. Unlike gasoline generators, Powerwall keeps your lights on and phones charged without upkeep, fuel or noise. Pair with solar and recharge with sunlight to keep your appliances running for days.

Read: Is the Tesla Powerwall worth it?

Free Solar Panel Battery Quote

Now That We’re Thinking About It — Let’s Define Some Terms

Now that you’re belly-deep in all things battery, it’ll be a good time to break down a few terms and ideas you may have read about, but don’t really know about.!

What Exactly is Depth of Discharge? 

Depth of discharge (DoD) just means how much the battery can hold a charge before it needs to be recharged. Like, your cell phone, example. If you had to recharge it every time it said 5%, you would have a 95% DoD.

What this means for you: look for a solar battery that has a high DoD, ideally over 95%.

Round Trip Efficiency?

Round-trip efficiency (RTE) just means how much energy your battery can give you, compared to how much it can store. Using your cell phone as an example, if you were only able to use 70% of your battery each time you charged it, the RTE would be 70%. This is slightly different from DoD in that it measures how much energy discharged compared to how much energy was put into it for each cycle.

What this means for you: since batteries lose efficiency each cycle (we all know this from our cell phone), look for a high RTE for your solar battery to maximize your savings and lifespan.

Battery Lifetime

Once again, since we all are very aware that batteries lose charge with each cycle, an extremely important factor to consider is battery life, and if the manufacturer provides a warranty.

A typical solar battery can last between 5 and 15 years, depending on how many cycles it goes through. Most leading manufacturers guarantee their batteries with a 10 year warranty.

What this means for you: choose a solar battery from a reputable company with at least a 10 year warranty. That way if anything goes wrong within 10 years, you’ll get a free replacement.

Read More: How Long Do Solar Batteries Last?

Battery Types

Another factor you’ll want to consider is the type of battery, as in what is the battery made of. The most common solar battery types are lead acid and lithium-ion.

What’s the difference? Lead acid batteries have been on the market for a long time and they have low DoD as well as a short lifespan. However, they are the least expensive option. Lithium-ion is what most home solar batteries from leading manufacturers are made of. Lithium-ion has a higher DoD and lifespan, and is a lot more compact and lighter than lead acid.

Among lithium-ion batteries, Lithium Iron Phosphate (LFP) is the safest option, compared to Nickel Manganese Cobalt (NMC).

Factors That Can Affect Battery Capacity

A major factor in choosing the right solar battery is how much energy you’ll want to store in your battery. This can depend on a lot of things. For example, how much energy does your house normally consume? How large is your solar panel system? What are your energy goals with a solar system and battery? What appliances and equipment do you want backed up in case of an outage?

These factors can and should be discussed with a professional to help make your decision to go solar or purchase backup batteries that much easier.

Ok, but how do I know these things are actually working?

Phenomenal question!

ADT Solar now provides two options for backup solar batteries: The Enphase Encharge and the Tesla Powerwall 2.

Also phenomenal: both Enphase and Tesla provide digital applications to see both how your home is producing and using energy.

What’s also cool about both of them: it’s compatibility with the National Weather Service. With Storm Watch enabled, the Powerwall and Encharge can communicate with the NWS and prioritize charging in anticipation of severe weather.

The Enphase Encharge battery has multiple microinverters placed inside the unit itself. So, if one of those inverters fails, the others pick up the slack to ensure the battery keeps on truckin’.

Other batteries use a single-string inverter, which means if that inverter fails, the whole battery goes down.

In Summation…

Batteries are a great addition to your solar panel array. What we offer at ADT Solar is safe, quality installation products from leading manufacturers to help you gain energy independence. The Enphase Encharge and Tesla Powerwall 2 are both exceptional choices to consider when going solar, but overall, the choice is yours. We just hope the information here helped you figure your way through the noise of solar battery backups and what they can do for you.

If you’re ready to make the transition to solar or add a battery to your existing system, get in touch with an expert at ADT Solar to answer all your questions and help you decide which battery could be right for you.

Get Your Customized Solar Panel Battery Quote


*Tax and credits or incentives including those provided by federal, state, or local governments may change or end. This can impact the amount of money you might save. Consult a tax professional to understand any tax liability or eligibility for any tax credits that may result from the purchase of your solar system.

**If you have taxable income and own the system, you may qualify for the federal investment tax credit (ITC). It is your responsibility to determine your eligibility and to apply. Consult a qualified tax professional for assistance and details. 

Going Solar 101 ebook cover

Download Our Free “Going Solar 101” Ebook:

  • This field is for validation purposes and should be left unchanged.

Find out how much you can save with ADT Solar