Solar Batteries: What You Need To Know Before Buying

A home with a solar battery cartoon

Do you want to help the environment and your wallet by using solar power? But are you worried about cloudy days, storms, and other risks that come with solar systems?

You can find out how solar batteries can help put some of your worries to rest. By the end, you’ll feel better about solar panel usage because of solar batteries.

What Are Solar Batteries?

A solar battery (also called a deep cycle solar battery) is a device that stores excess energy produced by your solar panel system. When sunlight hits your solar panels, electricity is generated in the form of Direct Current (DC). This needs to be converted into Alternating Current (AC) if you want to use it as an energy source. Solar batteries convert this DC energy into AC energy so it can be used to power your home. 

How Does A Solar Battery Work For Solar Panels?

When sunlight hits your solar panels and creates energy, some is used immediately, while excess energy is stored in the battery. You can use it when there isn’t enough sunlight for your solar panels to generate electricity. The amount of stored energy will depend on how much excess electricity is produced and stored.

How Many Will My Home Need?

One of the types of solar batteries

The number of solar batteries you need for your home will depend on the size of your house, kilowatt-per-hour (kWh) requirements, and your energy consumption habits.

If you have a large home with multiple levels, you will likely need more solar batteries than someone with a small one-story home. 

Another factor that affects how many solar batteries you need is the kilowatt-per-hour (kWh) requirements your home has. An electrician or energy specialist can determine this for you.

Finally, it’s important to consider your own energy consumption habits. If you use more electricity during certain periods, you may require additional battery capacity to meet these demands without draining existing resources too quickly.

*Blue Sky Electric can estimate how many solar batteries your home will need based on your electrical bill and utility company history.

Cost For Solar Batteries

Lead-acid batteries are widely used for residential applications, and they can range in price from $200 up to $800 per battery.

Lithium-ion solar batteries tend to be more expensive than lead-acid batteries. The average cost of a residential lithium-ion solar battery system with installation falls in the $7,000 to $14,000 range, although many entry-level systems start at around $20,000. A mid-size system is usually between $20,000 and $40,000, depending on the manufacturer.

A 3 kWh system from Generac is about $2,500. 

Installation Costs

Installation costs can vary significantly depending on your home’s existing electrical setup and other factors such as roof shape or access difficulties.

Types Of Solar Batteries

Lead-Acid Batteries 

Lead-acid batteries are the oldest type of solar battery and remain one of the most affordable options. However, lead-acid batteries typically have a shorter lifespan than other types and require regular maintenance. They also contain hazardous materials that can be dangerous if not handled or disposed of properly. 

Lithium-Ion Batteries 

Lithium-ion batteries are the most common type today because they provide high energy levels and don’t require much maintenance. They’re also lightweight and easy to install. That said, lithium-ion batteries tend to be on the more expensive side. 

*Blue Sky Electric mainly uses this battery type.

Nickel-Cadmium Batteries 

Nickel-cadmium (NiCd) batteries are similar to lithium-ion in terms of their durability and reliability. But NiCd batteries have a shorter lifespan and are considered an environmentally hazardous material that must be handled cautiously when installed or disposed of. 

Flow Batteries 

Flow batteries are a popular option for storing large amounts of energy over long periods. These systems use two tanks filled with electrolytes that flow through a central cell stack when charging or discharging electricity. Flow batteries tend to be large, sometimes taking up entire rooms, and can be costly upfront due to their size and complexity.

Sealed AGM Batteries

Sealed absorbed glass mat (AGM) batteries don’t require maintenance since all components are sealed within the casing. These systems tend to have longer lifespans than other types and require minimal space for installation purposes. But, AGM systems tend to cost more upfront than other types due to their advanced features. 

Sealed Gel Cell Batteries

These systems are similar in many ways to AGM models but rely on a thicker gel electrolyte solution for fast recharging capabilities and superior performance in extreme temperatures. Sealed gel cell systems can last up to 10 years before needing replacement. Remember that these will come with a heftier price tag due to their advanced features.

The Best Solar Battery

The best solar battery has the specifications that best meet your needs. At Blue Sky Electric, we prefer using Generac batteries and/or lithium-ion.

Considerations When Choosing Solar Batteries

Home solar panel system with battery


The type and material of your solar battery will largely depend on how you plan to use it. Lead-acid batteries are popular due to their relatively low cost and long lifespan. Lithium-ion may be the better choice if you want a battery with a longer life span. If you plan on using your battery in extreme temperatures or harsh conditions, you’ll need one specifically designed for those conditions. 

Battery Life 

The life expectancy of any given solar battery will depend on its type, quality, and usage history.

  • Most lead-acid batteries can last between 5 and 10 years when properly maintained and used correctly
  • Lithium-ion batteries typically have longer lifespans—upwards of 20 years—but they tend to be more expensive

Discharge Depth (programmable) 

The discharge depth of a solar battery is essentially how much power it can provide over time without being damaged or drained too quickly.

This is measured in terms of percentage. For example, a 20% discharge depth means that the battery can provide up to 20% of its total capacity before needing recharging. So if it has 100Ah capacity, it can provide 20Ah before needing recharge time.

If the discharge depth is lower, it will require less maintenance. But it also won’t provide as much power. If the discharge depth is higher, it will provide more power, but it’ll need more maintenance to keep it running well.


Efficiency refers to how well your solar panel system can charge and store energy from the sun’s rays.

A system with high-efficiency rates can convert more sunlight into usable electricity with fewer components. Systems with low-efficiency ratings may need additional components to produce enough electricity for you.


Most manufacturers offer warranties on their products which guarantee that they will perform correctly under normal operating conditions within a specified duration after purchase.

Deciding On Battery Specifications For Your Home

What You’ll Use It For

Do you need a system to run your home off-grid or just during a power outage? Will it need to power your home along with other systems?


If someone in your household requires electrical support for medical reasons, you must make sure that you choose a battery with adequate safety features.


Think about how much money you can realistically afford to spend on a solar battery for your home. Evaluate all available options and decide which best meets your requirements and budget constraints.

Power Rating

The power rating of a solar battery refers to its ability to store energy over short periods. Higher power ratings usually mean higher costs, but they also mean more efficient energy storage over shorter periods.

Battery Capacity

Different types of batteries have different capacities; some claim they are better than others, but ultimately it’s up to you which type best meets your needs and budget constraints.

Roundtrip Efficiency

The roundtrip efficiency measures how much energy can be stored from one cycle, or the “round trip” from charging up the battery from empty, then draining it back down until it is empty once more.


The makeup of the battery will affect its overall performance in terms of power output, efficiency, and lifespan. Chemistries offer different benefits depending on your specific needs; lithium-ion batteries tend to last longer but require deeper cycles. Lead-acid batteries may not last as long but require less frequent recharging cycles.

Tips For Deciding Which Battery You Need

  • For more power, choose a solar battery with a high power rating
  • For powering an energy-intensive appliance, choose a solar battery with a high instantaneous power rating
  • For powering your home over an extended period, choose a solar battery with a higher usable capacity
  • For getting the most out of every kilowatt-hour, choose a solar battery with a higher roundtrip efficiency 
  • For the most power that takes up the least space, choose a lithium-ion nickel manganese cobalt (NMC) solar battery
  • For the longest life that you can cycle the most, choose a lithium iron phosphate (LFP) solar battery
  • For the highest safety rating, choose an LFP solar battery
  • To be off-grid, look for a solar battery that can keep up with the kilo-watt usage of your home. You’ll also want a generator

Popular Solar Batteries

Generac and Tesla have emerged as two popular options among solar batteries due to their dependable performance, state-of-the-art technology, and affordability.

Generac is a well-known name in the home backup power industry, with its Guardian Series providing high-quality solar storage solutions to homeowners just about anywhere.

Tesla’s Powerwall is designed for residential and commercial use, with the latest generation boasting powerful features such as long-lasting storage for up to 10 days and a peak power of 7kW.

The most popular type of solar battery is lithium-ion.

Will Solar Batteries Be Worth The Cost?

Installing solar batteries comes with many potential benefits. They can help you save money on energy costs by storing energy when rates are lower and releasing it when rates are higher. Solar energy is clean and renewable, making it an environmentally friendly power source. Depending on where you live, you may find incentives or rebates for installing a solar battery system that can offset some of the cost. 


Do solar batteries have disadvantages?

Cost & Lifespan 

Solar batteries can be expensive and have an average lifespan of 10 years.


Solar batteries are low-maintenance but need occasional servicing to keep them running efficiently. Some tasks you may be able to do yourself. This may include checking connections, cleaning terminals, checking voltages, etc., all of which will require time and possibly money if done by a professional. 

Space Requirements 

Solar batteries may take up space around your home, but it’s usually less than other energy sources such as generators.


They may not be as powerful as other sources when supplying power during peak times or when the temperatures drop below 40F degrees Celsius outside. 

Risks Involved 

There are risks associated with solar batteries, such as leakage or overheating—but these risks have decreased over the years due to technological advancements in battery production and storage technology.

Needs Professional Installation

Professional installation is often recommended due to the complexity involved in setting up multiple solar batteries for maximum efficiency. 

How many solar batteries does it take to power a home?

There is no one-size-fits-all answer when it comes to powering your home with solar batteries. The number of batteries you’ll need depends on several factors, including the type of battery, storage capacity, system size, and your energy requirements. 

You can estimate your needs by calculating the kilowatt-hours you’ll need during a power outage and comparing that to batteries and systems.

What solar batteries are best?

When choosing a battery system for your home solar energy system, it is important to consider how you will use it. For example, do you need it for everyday use or for longer periods? Sealed lead-acid and lithium batteries are usually good options depending on what you need.

Many companies make solar batteries, including Generac, Tesla, Panasonic, LG Chem, Electriq Power, Enphase, Sunpower Solar Edge, SunVault, and Renogy.

Power Your Home With Blue Sky Electric

Investing in solar batteries can offer numerous benefits to your home energy needs.

Blue Sky Electric is the perfect partner for this journey, as we have everything you need, from helping determine how many solar batteries you need to the installation. We understand the complexities that come along with powering your entire home with renewable energy.

Fill out our contact form today and get started on becoming more conscious of your electrical usage.