What to Know About Lithium Batteries
Dec 2nd 2020
Are lithium batteries the best option for solar installations?
There was once a time when adding battery storage to a solar installation was out of reach for most people due to the high cost of battery technology. However, with dropping costs and improving technologies, there’s never been a better time to include a battery bank in your solar panels. Lithium iron phosphate batteries in particular have come a long way, and they are a highly efficient, long-lasting, and low-maintenance storage solution that can be compatible with a range of solar installations.
Whether you’re looking to add battery storage to make your on-grid solar system more powerful or are living the off-grid dream, solar batteries can transform your solar installation and give you increased flexibility, capacity, and ease of mind. Lithium iron phosphate batteries are an ideal storage solution for those looking for an efficient battery that has a long lifespan and requires little to no maintenance.
What are deep cycle batteries?
Deep cycle batteries will be your go-to for any battery bank for a solar installation. In contrast to car batteries which only provide short bursts of energy, deep cycle batteries are designed to provide sustained energy over a long period of time.
In a solar installation, your deep cycle batteries store the energy that is collected from your solar panels. The higher your battery’s capacity, the more solar energy you can store in your system.
What should I consider when shopping for solar batteries?
Price: The cheapest lead acid battery can cost around $150, while lithium iron batteries can cost upwards of $2,000. However, don’t let that sticker shock scare you away. You need to consider the overall lifetime costs when deciding on a battery. For example, you will have to replace lead acid batteries before you will need to replace a lithium iron battery, so it’s important to take into account the overall lifetime costs.
Capacity: Battery capacity, which is measured in total amp hours, refers to the amount of energy a battery can store. If you need to power certain appliances for long periods of time, you'll need more batteries to carry a bigger load.
Cycle Life: This specifies the number of discharge and charge cycles a battery can provide before the capacity drops below the rated capacity. This varies sharply from technology to technology and is measured by the number of cycles.
Do I need battery storage?
I live or travel in a van, RV, or motorhome: Yes!
We highly recommend battery storage for those living a mobile lifestyle in vans, motorhomes, or RV’s. With a battery bank, you’ll be able to keep things running even when your panels aren’t producing energy. You also typically won’t need a noisy, dirty gas-powered generator anymore.
I live in a home with access to the electrical grid: Battery banks can be useful in case of outages.
Battery storage can be beneficial for homeowners who are still connected to the grid. If you’d like to run your solar panels in the case of grid outages, battery storage is a great way to ensure continued energy access when you need it most.
What should I know about Lithium Iron Phosphate batteries?
Lithium iron phosphate batteries have an extremely long cycle life, high discharge and recharge rates, and are incredibly compact and lightweight. They also require little to no maintenance. That being said, they are also the most expensive battery option on the market.
Lithium batteries typically have a lifespan of at least 10 years and lose less capacity when idle. This is especially useful in cases where solar energy is only used occasionally. They also have the best cycle life of deep cycle batteries, offering approximately 2000 cycles at 100% DoD (depth of discharge.)
A great battery worth considering is the Renogy Smart Lithium Phosphate Battery 12 Volt 100AH, which is lightweight, safe, and suitable for many applications.
Pros of Lithium Batteries
• Requires little to no maintenance
• Long lifespan
• Best cycle life
• Compact and lightweight
• Loses less capacity when idle
Cons of Lithium Batteries
• Most expensive battery option
• Smaller temperature range than other batteries
Do lithium batteries charge faster than lead acid batteries?
Yes they do! As mentioned above, lithium iron phosphate batteries are more efficient and have a faster rate of charge. Lead acid batteries are limited in how much charge current they can handle, mainly because they will overheat if you charge them too quickly. However, lithium iron phosphate batteries can typically handle a higher amperage. This means they can be recharged much faster than sealed and flooded lead acid batteries.
What is the lifespan of lithium iron phosphate batteries?
Lithium iron phosphate batteries typically last about 10 years. The Renogy Smart Lithium Iron Phosphate Battery is rated to last at least 4,000 cycles at 80% depth of discharge. Lithium iron phosphate batteries also lose less capacity when idle.
I only using my batteries sometimes. Are lithium batteries a good option?
Compared to other battery technologies, lithium iron phosphate batteries lose less capacity when idle. This is especially useful in cases where solar energy is only used occasionally. They also have the best cycle life of deep cycle batteries, offering approximately 2000 cycles at 100% DoD (depth of discharge.) This 12V lithium battery also comes with Bluetooth which allows you to connect to the mobile app for tracking the battery's condition.
What size battery bank do I need?
When planning your solar installation, it’s important to properly size your system to ensure your battery storage will meet your needs. On the flip side, you also don’t want to oversize your system and waste money on large components that you don’t need.
Energy usage is measured in kilowatt hours. For example, if you need 1,000 watts for 5 hours per day, then your energy usage is 5kWh per day. To size a system that will best fit your needs, we recommend making a list of all the devices you plan on running. The Renogy solar power calculator makes calculating your energy needs quick and easy.
How to maintain your battery bank for best performance
Lithium iron phosphate batteries are known for being incredibly low maintenance. In contrast to flooded lead acid batteries which require monitoring water levels, lithium batteries are much more hands off. However, there are some things we do recommend to ensure a long life. We recommend charging your batteries fully once a month, in order to equalize the batteries in your bank. If sunshine is not readily available, Renogy has a range of battery chargers available to help you maintain your batteries. You can also use an amp hour meter to see if the batteries are fully charged. We also recommend checking to see what your solar system is outputting at least twice a year to make sure you don’t have any underlying issues in your system.
Conclusion
Lithium iron phosphate batteries are an incredibly versatile, powerful, and efficient battery option for many solar installations. Even though they are the most expensive, lithium iron phosphate batteries have an extremely long cycle life, high discharge and recharge rates, are compact and lightweight, and require little to no maintenance. Because of all these benefits, it’s easy to see why they are becoming the most popular battery storage solution for many solar owners.
See other related articles at Renogy：
Solar Panels Maintenance Best Practices And Costs
A Guide to Installing Solar Panels On Van Or RV
Solar Panels 101: A Beginner's Guide
The Ultimate Guide To DIY Off-Grid Solar Systems
Do solar panels increase home value
How efficient are solar panels
How Many Solar Panels Do I Need
