It is well known that 12v lithium-ion solar cells are the best way to store solar energy in small off-grid power systems.
With the price of complete solar kits and solar storage capacity continuing to drop, now is the perfect time to take advantage of lithium-ion technology.
Shop Solar Kits understands that off-grid solar systems are only as good as their ability to store power in the field. We've patched, tested and sold thousands of lithium-ion batteries over the years and are always working to find the next best solar storage battery.
Here, we outline what to look for when buying a 12v lithium-ion battery, then review our picks for the top five lithium solar cells.
You can use 12V lithium-ion batteries in golf carts, boats, and tons of other applications. While we focus on off-grid solar storage, there are six key features to consider about lithium-ion solar batteries before choosing the best battery for your application. So let's dive in.
First and foremost, storage capacity is the most important thing to know about a 12v lithium-ion battery. Storage capacity is measured in watt-hours (Wh) or amp-hours (Ah) to approximate the battery's discharge run time.
Lithium-ion batteries come with the advantage of being able to discharge their capacity without damaging the system. As such, it is simple to calculate how long your battery will last.
Feel free to use our solar load calculator to calculate your average daily electrical demand based on the wattages and runtimes of your electronics and appliances.
Next, it is critical to verify a 12v lithium-ion battery’s estimated life cycle count before purchasing. Lithium solar batteries can be expensive, and life cycle counts help estimate the approximate lifespan of the storage.
Over time, batteries slowly degrade and lose a portion of their capacity to store electricity, known as the depth of discharge (DoD). Most commonly, lifecycles are an estimate of a number or range of full recharges before the battery reaches 80% DoD.
If a battery is rated at 1000Wh with 500 lifecycles at 80% DoD, then it can hold approximately 800Wh of electricity storage after 500 full uses.
All 12v lithium-ion batteries have an approximate shelf life which refers to the amount of time they can be left idle while maintaining their charge capacity. Sometimes, manufacturers refer to this as the maximum time between recharges, while others try to hide the term altogether.
A good shelf-life rating is critical if you plan to only use a 12v lithium-ion battery pack as an emergency source of power. In areas without sufficient sunlight, off-grid solar energy systems must have several 12v lithium-ion batteries on hand for extended periods of consumption.
If you use your lithium solar battery every day, then the shelf life isn’t nearly as important. In general, anything from 3 to 6 months is an average shelf life typical of high-quality lithium-ion batteries.
Of course, shelf life, lifecycles, and battery ratings mean nothing if your battery is defective. Like all electronics, lithium solar batteries may malfunction, so a good warranty is important to ensure the ongoing success of your off-grid system.
Long warranty periods, like seven, 10, and 12 years, can help you get the best return on investment for a lithium solar battery. Companies like Lion Energy provide lifetime warranties with some of their products. As always, it is important to read the fine print in a battery warranty and be careful not to do anything that would void a full refund.
Compared to AGM and lead-acid batteries, 12v lithium-ion batteries generally have more advanced battery management features. Advanced lithium-ion batteries with smart BMS temporarily absorb higher voltages and allow for highly efficient charging and discharging.
Generally speaking, smart BMS systems that automatically adjust electricity flows are considered premium features and designed to protect against possible damage to the system.
Thanks to recent developments, some of the newer lithium-ion batteries on the market make it easier to take complete control of the internal BMS. While some companies use an app (see KiloVault below), others use an onboard LED or LCD screen.
Last but not least, consider the temperature rating of the 12v LiPo battery before making your final decision. If you plan to take your battery into cold weather conditions (in a van, RV or home), it's good to know that your technology can work without putting you in the cold.
There are a few temperature ratings to keep in mind. Namely, batteries have charge, discharge and storage temperature ratings that indicate how they can be used safely while maintaining normal operating conditions