LG Solar Battery Lineup (2024 Costs, Reviews & Comparisons)
By Aniket Bhor /
In this guide on lithium solar batteries, you’ll learn:
Each product and or company featured here has been independently selected by the writer. You can learn more about our review methodology here. If you make a purchase using the links included, we may earn commission.
When you decide to go solar, you’ll have an array of solar panels installed on your roof. If you don’t know how solar panels work, they collect energy from the sun and convert it into an electric current. The direct current (DC) electricity passes through an inverter, which turns it into an alternating current (AC), the type of electricity we use in our homes.
Most home solar installations are connected to the local power grid, meaning any excess energy produced by your solar energy system is fed back to the grid. If your utility company has a net energy metering program, you can receive credits for this excess energy. If your solar system does not produce enough energy to power your home at any point, you’ll draw energy from the grid.
Solar batteries are renewable energy storage systems that store energy produced by your solar system rather than sending it back to the grid. This allows you to use the stored energy when your solar panels are not producing any energy (like after the sun sets or on overcast days). Lithium solar batteries are energy storage devices typically made with lithium iron phosphate.1
Before we get into specifics, you should know that there are a few different types of lithium technology — regular lithium, lithium-ion and lithium iron phosphate (LiFePO4 — also known as LFP). Standard lithium batteries are not rechargeable and, therefore, not fit for solar.
We already use lithium-ion technology in common rechargeable products like cell phones, golf carts and electric vehicles. Most lithium-ion solar batteries are deep-cycle LiFePO4 batteries. They use lithium salts to produce a highly efficient and long-lasting battery product. Since they are deep-cycle batteries, the products do very well even when the attached solar panels experience inconsistent charging and discharging.
Before Tesla developed its Powerwall I lithium-ion solar battery 2015, most solar batteries used lead-acid battery banks. There are now many lithium-ion solar batteries on the market, allowing a range of options for homeowners and their various needs.
Here’s a helpful video to learn more about the differences between lithium-ion batteries and lead-acid batteries:
The best battery type for your solar system will depend on several factors, like what your system powers, if you are on or off-grid, and how often the system is used.
There are a variety of benefits of lithium-ion and LFP batteries over lead-acid batteries, but they might not be ideal for every solar setup. Let’s take a look at some pros and cons.
Pros | Cons |
Higher depth of discharge (DoD) | Premium Cost |
Long lifespan | Thermal runaway |
High efficiency | |
High charge rates | |
High energy density | |
Low maintenance |
The DoD of a battery is the amount of the stored energy in the battery that can be used relative to its total capacity. Most batteries come with a recommended DoD to maintain the health of the battery.2
For example, the Tesla Powerwall II has a 100% depth of discharge (or so it advertises), which theoretically means that you can use 100% of the energy in the battery before it has to be recharged (we believe that it’s closer to 80% — fully draining the Powerwall between charges will significantly lower the battery life).
Lithium-ion batteries have a high depth of discharge, meaning homeowners can use more stored energy without having to charge it as often. Lithium-ion batteries can handle discharging around 80% of their charge before needing to be refilled, as opposed to a lead-acid battery, which should only be run to 50% depth of discharge.
Lithium-ion batteries have a substantially longer lifespan than lead-acid batteries because of their high DoD. A high DoD means that they don’t have to be recharged as often. The more you recharge a battery, the shorter its lifespan will be (similar to an iPhone).
Battery efficiency refers to the amount of energy you get out of a battery relative to the amount that you put in.
Lead-acid solar batteries are notoriously high-maintenance. Inconsistent use can lead to damage and deterioration of its lifespan. This is not a concern for lithium-ion batteries. Lithium-ion batteries accept a larger amount of charge current, leading to shorter charging times.
Partially charging lithium-ion batteries also has little to no effect on their lifespans and performance. But with lead-acid batteries, it is recommended to fully recharge the batteries after discharging any amount of energy. Partial charges can reduce a lead-acid battery’s lifespan.
Lithium-ion batteries store more power with less space than lead-acid batteries. This makes them a great choice for homeowners, as lithium-ion batteries can be stored in garages or even mounted on walls.
Unlike lead-acid batteries, lithium-ion solar batteries do not need regular maintenance. This can save you time, money and the hassle of servicing your batteries.
Lithium-ion batteries are typically the most expensive residential battery storage option. The upfront price tag can lead to sticker shock, especially when compared to lead-acid batteries.
However, they are more cost-effective in the long run. Lead-acid batteries need to be replaced more often and require more maintenance. Keep in mind that solar battery systems qualify for incentives like the federal solar investment tax credit. Certain states even have standalone tax credits for solar energy storage systems.
Thermal runaway is one of the primary risks related to lithium-ion batteries. It is a phenomenon during which the battery enters an uncontrollable, self-heating state. Thermal runaway can result in the ejection of gas, shrapnel, particulates or fire.
When properly installed, the risk of a lithium solar battery overheating is slim to none.3
The total cost to install a lithium battery storage system can range anywhere from $4,000 to over $25,000. While that is a big cost range, the total price depends on:
The higher price tag comes with the benefits that lead-acid batteries can’t provide, like a longer lifespan and lack of needed maintenance.
There are many high-quality lithium solar batteries on the market in 2022, but the most well-known choice is the Tesla Powerwall II battery. It is one of the most cost-effective lithium-ion solar batteries, costing around $12,000 with all parts and installation factored in. Below, you’ll see our picks for the best lithium solar batteries and a side-by-side comparison.
Tesla Powerwall 2 | Enphase IQ 10 | Generac PWRcell | LG RESU | BYD Battery-Box HV | |
Battery Capacity | 13.5 kWh | 10.5 kWh | 9-18 kWh | 9.3 kWh | 5.1-12.8 kWh |
Continuous Power Rating | 5.8 kW | 3.84 kW | 3.4-6.7 kW | 5 kW | 5.1-12.8 kW |
Depth of Discharge (DoD) | 100% | 100% | 84% | 95% | 100% |
Round-Trip Efficiency | 90% | 96% | 96.5% | 94.5% | 95% |
Price | $12,000 | $5,000- $10,000+ | $9,000+ | $7,000 | $4,000+ |
Warranty | 10-year warranty | 10-year warranty | 10-year warranty | 10-year warranty | 10-year warranty |
To get the most out of your entire solar system, you will need more than just state-of-the-art solar panels. A reliable and efficient solar battery can help you save energy and money in the long run. Make sure you explore your options and account for your home’s specific energy needs when choosing the best solar batteries for your system.
A consultation with a certified company is a great way to find out what type of battery would work best for your home, how much your solar system would cost and how much you can save by taking advantage of local and federal solar incentives.
Below are some of the most common question that EcoWatch receives from our readers about lithium-ion solar panels. If you have a question that isn’t answered below, feel free to reach out to us!
Lithium batteries can be used for off-grid campers, but they are not always necessary. Lead acid batteries are often less expensive than lithium battery packs, so many people will choose these batteries for their backpacking and cabin use. However, those who camp more often may want to invest in a lithium battery pack because they have a longer cycle life.
The most important things to look for are a larger amp-hour rating, low discharge threshold to prevent damage, internal battery management system, quality customer service and competitive warranties.
Both lithium batteries and AGM batteries have their pros and cons, but many people choose lithium batteries for their grid-tied solar projects due to their longer life expectancy and low maintenance.
To charge a typical 12-volt lithium battery, you will need at least a 100-watt solar panel that has access to five or six hours of direct sunlight per day. The wattage you need can also depend on your geographical location, access to direct sunlight and the efficiency of your solar panels.
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