Rechargeable Solar Battery System For Your Home
Consult with your sales representative for battery availability and backup capabilities in your area. Available while supplies last.
Generate, store, and manage clean, affordable solar energy on your terms. With Sunrun Brightbox, your Brilliant Home™ comes full circle. Brightbox is more than just solar battery storage—it’s a holistic service that puts the power in your hands. We only partner with top-notch innovators in lithium-ion battery technology, so you’re backed by the highest quality products available. Brightbox is currently available to new Sunrun solar customers only.
Sunrun helps you go solar and finds the back-up options that best fit your needs.
Our solar-powered batteries are best-in-class. Choose to back up your whole home with Tesla Powerwall, or just the essentials with LG Chem.
Our customized plans give you the financial flexibility you need. Choose from multiple lease, financing, and cash options.
We’re with you every step of the way. From finding the right solar plan to monitoring your solar system, Sunrun safely sees you through your solar journey with our Solar Guarantee. Go solar virtually with no in-person contact.
Keep the lights on, protect your family and secure your home office during blackouts. Our 100-year-old utility grid is expensive, dirty, and susceptible to extreme weather. As blackouts become the new normal, Brightbox backs you up with reliable, clean energy for your home and family.
Brightbox can buffer you from increasing energy costs so that you have power when you need it most. While we can’t predict how much or how often utility electric rates will rise or when exactly the power will go out, we can always count on the sun rising each day. Take charge of your electric bill and get control of your energy needs now and in the future.
The benefits of solar-powered batteries go beyond your home. Brightbox’s solar battery service enables you to consume more of the clean energy your solar panels produce, so you rely less on dirty and damaging fossil fuels while you decrease your carbon footprint. A cleaner and safer future starts today, and you can help create it by building a smarter energy grid.
Reliable energy when you need it most.
Find solar battery availability, information, and Sunrun locations near you. If we’re not there already, we may be in your community soon. Sunrun is committed to growing solar locally.
What kind of solar batteries does Sunrun use?
Brightbox offers two lithium-ion solar battery storage options: Tesla Powerwall and LG Chem. Compared to lead acid batteries, solar batteries using lithium-ion technology are more efficient and have longer lifespans. This makes them one of the best energy storage options when going solar.
Tesla Powerwall can provide whole home backup while LG Chem backs up to four circuits. There are also differences in the software and app functionality.
Request a free quote to get connected with a Sunrun Solar Advisor and determine which back-up solution will best meet your energy needs.
Are there solar storage incentives available?
One of the best solar storage incentives is the Federal Solar Tax Credit. The Federal Solar Tax Credit will deduct 26% of the cost of your solar energy system from your federal taxes. Starting in 2021, the value of the tax credit will step down to 22%. After 2021, the tax credit for residential solar ends.
Another option is to finance Brightbox with a lease. We’ll pass down the savings to you in the form of a lower and more predictable electric bill.
Net metering, which credits any excess power your solar system generates back to your electric bill, is another great incentive for many people that go solar. However, several states have chosen to adopt Time-of-Use (TOU) rates, which complicate the way your net metering credits are calculated. Brightbox can buffer you from peak TOU rates so you may save even more on your electric bill.
Solar Battery Cost Breakdown
Before we go any further, it’s important that we provide you with some context to the information shown in the tables below: In order for us to provide you with the most accurate solar battery cost estimates, we collected data from over 100 different batteries, from the following manufacturers:
- Battle Born
- Ampere Time
- AIMS Power
- MK/Deka Batteries
- Concorde Battery
- Future Solar
- Sun Xtender
- Outback Power
Additionally, we based the solar battery cost estimates according to ampere hour and voltage.
Based on our research, we discovered the following:
- There are a number of manufacturers that don’t provide the for their batteries online. This makes it difficult for online consumers to compare and contrast prices.
- The majority of the data that we found related to batteries in the 12V range.
Because of this, we felt it important to FOCUS on 12V Lithium-Iron (LiFePo4), AGM, and GEL batteries.
Technically, we could provide 24V and 48V but the sample sizes simply weren’t big enough at those ranges (at least in our books) for us to give you accurate cost estimates. The lack of 24V batteries on the market is actually one of the reasons why many are looking to convert 12V To 24V for better efficiency.
Please Note: We will keep an eye on the market and update this article with 24V and 48V cost estimates in due course. So, stay tuned!
Now, let’s have a look at what we found!
Solar Battery Manufacturer Cost Comparison
Here you’ll find a cost comparison between a variety of manufacturers.
You’ll notice that we haven’t included all of the manufacturers that we originally listed. Again, this is because some of the data sample sizes were too small, or the company simply doesn’t have batteries available in these sizes.
Average Cost Of Lithium-Iron Batteries (LiFePo4)
What Factors Determine Solar Battery Cost?
Not all batteries are created equal. Yes, we know that’s very cliché but it’s true nonetheless.
So, now that you’ve had a good look at our solar battery cost estimates, let’s dive into the factors that can influence an individual battery’s price point.
Here are some of the factors that determine the cost of a solar battery:
Any solar-related product’s price tag will depend on the company that manufactures them. This goes for inverters, batteries, panels, EV’s, etc.
This can come down to their manufacturing process, marketing strategy, material cost, and other various overheads.
For those of you who’ve taken a look at the above tables – you may have noticed a significant difference in price relative to the type of battery chemistry/technology.
In this article, we’ve included for both lithium-iron (LiFePO4) and lead-acid (AGM GEL) solar batteries. Out of the 3, LiFePO4 batteries tend to be the most expensive – at least initially. Over time, they actually save you money because they last longer.
To explain this, here’s a brief summary from our article – Lead-Acid vs Lithium-Ion (10 Key Differences):
Levelized Cost Of Storage
The Levelized Cost of Storage (LCOS) is the most appropriate way to compare the cost of different battery technologies. This variable is expressed in USD/kWh and takes into account all of the expenses related to energy storage over the lifespan of a battery.
As batteries are maintenance-free, the only cost you incur is the price of the battery itself. Have a look at the table below
As you can see — initially, the price of the lithium-ion battery (LiFePO4) costs 4X more than the lead-acid battery.
However, it lasts much longer and thus it has the lower LCOS. In short, over its lifespan, the lithium battery is two times cheaper than the lead-acid.
The durability of a battery is another factor that greatly influences solar battery cost.
This metric is rated in the number of cycles (charge/discharge) and in years.
A battery’s tolerance towards intermittent charging/discharging is a good example and indicator of durability.
Why? Solar panels are non-linear generators — their power output varies continuously according to the availability of sunlight irradiation. For instance, a passing Cloud can drastically influence power variation (several hundreds of watts).
It stands to reason then that your battery should be ready for such events. Fortunately enough, LiFePo4 batteries can handle power fluctuations rather well.
Batteries that come with quick charging/discharging are naturally more expensive.
Lead-acid batteries don’t support quick charge — this makes them cheaper. Their charging time range from 6 to 15 hours and follow a 3-step process:
- Bulk charge — charging voltage increases steadily to its maximum value and charging current is kept at its maximum value. The battery will reach up to 80% of its full capacity in approximately 6 to 8 hours.
- Absorption charge — charging voltage is kept at its maximum value, while the current slowly decreases until the battery is charged at 90-95%.
- Float charge — charging voltage and current decreases to zero, while the battery reaches full charge.
Conversely, lithium batteries are fit for quick charging.
You’re able to charge them to 80% of their full capacity in just 1 to 2 hours (depending on the power output of your charger).
The remaining 20% will take another 2 to 3 hours. Therefore, you can fully charge a lithium-ion battery in 3 to 5 hours.
Both types of batteries support quick discharge and can provide intense pulses of current (hundreds of amps) if required.
Battery capacity refers to the maximum amount of energy that can be stored and extracted from a battery. This is expressed in kilowatt-hours (kWh) as well as ampere hours (Ah/Amps).
Which Type Of Solar Battery Is Worth The Cost?
Think of it like this — a solar battery’s worth is contextual.
You could go out and buy yourself the most expensive battery on the market, but if its specifications aren’t suited to your needs, then it simply isn’t worth the money.
But that’s a pretty lazy answer — so how do we attack this question?
Well, one of our aims here at Climatebiz is to arm our readers with the knowledge to make informed decisions.
In this case, we’re going to provide you with background information on each type of battery technology. That way, you’ll have a better understanding of what battery type is best suited to your needs.
Lithium-Iron Batteries (LiFePo4) Overview
LiFePo4 batteries are the most common type of lithium solar batteries out on the market. They have the following components:
- Positive electrode: Lithium oxide LiFePo4 (Lithium Iron Phosphate)
- Negative electrode: Carbon
- Electrolyte: lithium salt (Li, gel type)
- Membrane separator
Their working principle is based on the exchange of lithium ions (Li) from one electrode to another — this is thanks to the electrolyte. This flow of ions generates a current outside the battery cell.
- High storage capacity
- Fitted for intermittent charging
- High power output
- Very durable (5000 cycles, 10 years)
- Accepts quick charge
- Tolerates high temperatures well
Types Of Solar Batteries
There are many types of solar batteries being used today. Some of the battery types are:
Absorbed Glass Mat (AGM)ALA
Lithium Iron PhosphateLFP
Lithium Nickel Cobalt Aluminium OxideNCA
Lithium Nickel Manganese Cobalt OxideNMC
Among the various types of solar batteries, the most affordable yet shortest-lived batteries are Flooded Lead-Acid batteries. These batteries typically have a lifespan of 500 life cycles or 1-2 years.
Next in line, in terms of affordability and short lifespan are Gel and AGM batteries which are an improved version of flooded lead-acid batteries.
Lastly, the most expensive batteries and yet the longest lasting would be the Lithium-ion batteries which include LFP, NCA, and NMC batteries.
How Much Does A Solar Battery Cost?
Besides the type of material used to construct the battery, solar batteries can be divided into two based on their storage capacity.
The first category features smaller solar batteries that individually have a battery capacity that’s insufficient for use in most homes. These batteries need to be linked together to form a bigger battery bank that can be used to power homes.
Using smaller batteries is often cheaper when building large-capacity battery banks. For example, building a 13 kWh battery bank using Renogy’s 12V 100Ah LFP batteries costs approximately 5,170. Accounting for the need for battery replacements, the total cost across 25 years is still less than 10,340.
The second category has large single-unit solar batteries with capacities usually over 10 kWh of capacity. An example is the Tesla Powerwall that’s no longer being sold separately. For the most part, batteries in the second category are more expensive than their smaller counterparts. A Tesla Powerwall usually retails at 12,000. So if you have to replace this unit before the panels’ 25-year lifespan is over, it will cost you over 20,000.
At the end of the day, it’s up to you to pick the battery sizes you prefer. Here at Renogy, we sell lightweight, reasonably-sized, and affordably priced Lithium batteries ranging from 0.6 kWh to over 4 kWh of energy storage.
We also have 100Ah and 200Ah 12V Gel and AGM Lead-Acid batteries that are even more affordable, with ranging from 200 to 450. Note these may be subject to change.
Factors Affecting Solar Battery Cost
The cost of a solar battery storage system plus installation depends on several factors that determine whether the final system cost is going to be high or low.
Examples of the factors that influence the cost of solar batteries are:
Size of the Battery’s Storage Capacity. Batteries with bigger storage capacities are more expensive.
Type of the Battery. Different types of batteries are made with different materials and technologies. Depending on the type, the battery will vary in different ways. For example, lead-acid batteries with the shortest lifespan are often also the most affordable. In contrast, long-lasting lithium batteries cost the most. So the battery type affects the cost to a large extent.
Battery’s Brand or Manufacturer: Different manufacturers produce batteries of different qualities, standards, and pricing. For example, our certified batteries will cost slightly more than poorly made batteries.
Location: Most governments today have tax credits, subsidies, and policies to encourage the adoption of solar by businesses and homeowners. Depending on your location, and the incentives available to you, the cost of the same solar battery can vary greatly.
What Should You Look for When Looking for Solar Batteries?
A lot of solar customers choose the Tesla Powerwall just because it’s the product they’ve heard about most often, and others may get shoehorned into a specific battery based on what their installer carries. We recommend choosing your battery carefully, even if it means installing panels with a different solar company.
Below are three things we’d specifically look for in a solar battery, along with a brief explanation as to why we think each is so important.
- Battery capacity: The storage capacity of your battery or batteries is a crucial thing to dial in. Oversizing your system means you’ll pay far more than you need to for backup power. Undersizing your system means you’ll only be able to power your home—or certain items in your home—for a short amount of time during an outage.
- Power output: Most customers forget to consider the continuous and peak power ratings of their batteries. These numbers ultimately determine how many electronics and appliances you can run in your home at once on battery power. A rating that’s too low might not meet your energy demands and could end up damaging your batteries.
- Islanding inverter: A lot of the big-name solar batteries include islanding inverters, but not all of them do. Under normal circumstances, your panels will not provide electricity to your home in the event of a power outage to avoid dangerous currents running through utility lines when workers are restoring power. An islanding inverter lets you separate your photovoltaic (PV) system from the grid entirely so that your panels can recharge your batteries even during an outage. That means you can stay off-grid for much longer than you otherwise would, making the most use of your batteries’ capacity.
Compare the Top-Rated Solar Battery Manufacturers
The solar battery manufacturer you opt for can determine the warranty you get with your equipment, the customer service you’ll experience in the event of a warranty claim, the overall quality and reliability of the battery and more.
Based on the company’s reputation alone, we’d recommend Tesla and SunPower. Tesla is well-known for providing advanced technology, and SunPower is one of the most trusted and reputable companies in the solar industry.
The table below includes a look at how these companies and the ones we’ve reviewed above compare to one another. Keep in mind that these scores are determined using average numbers for each specification we consider if the provider offers more than one battery option.
Compare the Top-Rated Solar Batteries
In addition to considering the manufacturer of your solar battery, it’s, of course, important to compare the batteries themselves to make sure you get one that meets your needs. Overall, our top recommendations are the Tesla Powerwall and the Panasonic EverVolt. The table below includes a comparison of these batteries and the other options we’ve reviewed above.
What Do the Solar Battery Specs Even Mean?
Looking at the battery specifications we’ve mentioned above can quickly get confusing. Not only are there a bunch of specs that vary pretty widely, but it’s also not apparent what each of them even means. Below, we’ll clarify what some of the less obvious specifications above mean and why we feel each is an important consideration.
- Per-battery capacity: The per-battery capacity tells you how much energy storage you get with each battery you install. The lower this number, the lower the barrier to entry into solar batteries as a whole. However, it’s important to consider this number in combination with the per-battery cost to see what you’re paying for each kWh. The SunVault from SunPower provides the highest per-battery capacity of our top picks by far.
- Total capacity in series: Many manufacturers let you install multiple batteries stacked together for greater total energy storage to provide more backup power to your home. The higher this number, the longer your system will be able to maintain power in your home through blackout conditions. Tesla lets you link 10 batteries together in parallel, providing the highest capacity in series of our top battery options.
- Price per kWh: The price per kWh is straightforward, but it’s something many solar customers overlook. The cost per battery is important, but the per-kWh price is more important for determining the value you get for your money. The Powerwall Plus has the lowest price per kWh of the options we’ve reviewed.
- Continuous power output: Continuous power rating tells you how much power your battery can continuously put out over long periods. The higher this number, the more likely your battery will be able to provide electricity to your entire home, including all appliances and electronics. A lower output could mean the battery is only suitable for emergency power in an outage. The Panasonic EverVolt has the highest continuous output of the options above.
- Peak power output: Peak power ratings are similar, but they tell you the highest amount of power your battery can put out without sustaining damage. The higher this number is, the more likely your battery will be to keep up with high demand during blackouts without losing efficiency. Panasonic’s solar battery also scores highest in this category.
- Depth of discharge (DoD): This spec tells you how much of the battery’s storage can actually be used to power your home. The closer this number is to 100%, the more usable capacity you’ll have per kWh indicated in the battery’s nominal capacity. For example, a 100% DoD on a 10 kWh battery means you have 10 kWh of storage. A 90% DoD on that same battery means you effectively only have 9 kWh of storage. The batteries from Tesla and Panasonic have the highest DoD at 100%.
- Round-trip efficiency: Round-trip efficiency tells you how much of the solar power being routed to your battery will actually be available for storage. All batteries lose some of the energy generated by your panels, but the higher this number is, the less energy you’ll lose in the transition to storage. Higher efficiency ratings are best in areas where energy costs are high and where you don’t have access to net energy metering (NEM), as they will help maintain more of the power your panels generate to offset utility bills. The Generac PWRCell has one of the highest round-trip efficiency ratings in the industry at 96.5%.