Lithium batteries are known for their high energy density, long lifespan, and low self-discharge rates, making them a popular choice for various applications, from boats to RVs. However, to ensure your lithium battery remains in optimal condition during periods of inactivity, proper storage is crucial. Whether you're storing batteries for the winter or during a prolonged break from usage, following the right steps can significantly extend their life and maintain their performance. Here’s a comprehensive guide on how to prepare your lithium battery for seasonal storage.

1. Charge the Battery to the Optimal Level

Unlike lead-acid batteries, lithium batteries can be stored in partial states of charge without damaging the battery. If you are storing the battery for more than three months, then it’s safe to store the battery at a 50 percent state of charge in the appropriate temperature range.

2. Store in a Cool, Dry Place

Temperature is a critical factor in the longevity of lithium batteries. Extreme heat or cold can accelerate degradation and reduce the battery's capacity. If you’re storing your battery for less than three months, it can be stored in temperatures anywhere between 23°F to 95°F (-5°C to 35°C). For storage longer than 3 months, the recommended temperature range is 32°F to 77°F (0°C to 25°C). A cool, dry place, away from direct sunlight or sources of heat, is ideal for storage.

3. Avoid Complete Discharge Before Storage

Lithium batteries should never be stored in a fully discharged state. A deeply discharged battery can fall into a state known as “deep discharge,” which may render it unable to recharge or significantly reduce its capacity. Always ensure the battery has some charge left before putting it away for the season.

4. Disconnect the Battery from Devices

If the lithium battery is part of a device that won’t be used during the storage period, it’s a good idea to disconnect or remove the battery entirely. Leaving the battery connected to a device can lead to a slow discharge over time, even if the device is turned off, which could result in over-discharge and damage to the battery.

5. Store the Battery in a Fire-Safe Container (Applies to Lithium Cobalt Batteries Only)

While lithium batteries are generally safe, they are not all created equal. Lithium cobalt-based batteries, such as lithium nickel cobalt aluminum oxide (NCA), are capable of thermal runaway or fire, especially if they are damaged or stored improperly. For added safety, consider storing your lithium cobalt-based batteries in a fireproof container, particularly if you are storing multiple batteries or larger capacity ones. This precaution does not apply to lithium iron lithium iron phosphate (LiFePo4) batteries, which do not pose this same risk of thermal runaway. This is one of the reasons why RELiON only manufactures LiFePo4 batteries - due to their inherent safety.

6. Check the Battery Periodically

During the storage period, particularly during extended periods of storage, it’s advisable to check on your lithium battery occasionally. This involves checking the charge level to ensure it hasn’t dropped too low. If the battery’s charge level falls below 20% or 12.5V dc, recharge it back to the optimal storage level. This will help prevent deep discharge and potential damage. Also, if you are storing the battery for over six months, the batteries should also be cycled every six months.

7. Avoid Exposure to Moisture

Lithium batteries should be kept away from moisture, which can lead to corrosion or short circuits. Ensure the storage area is dry and consider using silica gel packs or a dehumidifier in humid environments to protect the battery from moisture.

8. Prepare for Reuse

When you’re ready to bring the battery back into use after storage, check the charge level. If it’s been stored correctly, you may only need to top it off before using it. For optimal performance, allow the battery to warm up to room temperature if it was stored in a cold environment before charging or using it.

Properly preparing your lithium battery for seasonal storage is key to maintaining its health and longevity. By following these steps—charging to the optimal level, storing in a cool, dry place, disconnecting from devices, and checking periodically—you can ensure that your battery remains in good condition and is ready for use when you need it. If you have any questions about how to properly store your battery during the off season, get in touch with a technical expert at RELiON.