How to Prolong LiFePO4 and Lithium-ion Batteries

Modified on Thu, 13 Jul, 2023 at 9:42 AM

As battery care-giver, you have choices in how to prolong battery life. Each battery system has unique needs in terms of charging speed, depth of discharge, loading and exposure to adverse temperature.

Li-ion or LiFePO4 does not need to be fully charged as is the case with lead acid, nor is it desirable to do so. In fact, it is better not to fully charge because a high voltage stresses the battery.

How to prolong the life of your LiFePO4 battery and get the most out of it:

Avoid deep discharges. Deep discharges, which are when the battery is drained to a low level, can damage the battery and shorten its lifespan. Try to keep the battery charged between 20% and 80% of its capacity.

Avoid extreme temperatures. High temperatures can cause the battery to lose capacity, while low temperatures can slow down the battery's charging and discharging. Store the battery in a cool, dry place.

Use a slow charger. Fast chargers can heat up the battery and shorten its lifespan. Use a slow charger whenever possible.

Don't leave the battery plugged in when it's fully charged. Leaving the battery plugged in when it's fully charged can cause the battery to overheat and shorten its lifespan.

Calibrate the battery regularly. Calibrating the battery can help to improve its accuracy and performance.

Keep the battery clean. Dirt and dust can build up on the battery and prevent it from charging properly. Clean the battery with a soft cloth and a mild cleaning solution.

Use the battery's built-in protection features. Many LiFePO4 batteries have built-in protection features that can help to prevent damage. For example, some batteries have a built-in cutoff that will prevent the battery from being overcharged.

Be aware of the battery's limitations. Every battery has its own limitations. For example, some batteries may not be able to withstand extreme temperatures or high discharge rates.

Replace the battery when it's no longer performing well. As a battery ages, its capacity will decrease. If the battery is no longer performing well, it's time to replace it.

What is the best percentage to charge a lithium-ion battery?

The maximum charging current is 50 % for a gel battery, and 30 % for an AGM battery. The best percentage to charge a lithium-ion battery is between 20% and 80% of its capacity. Charging the battery to 100% can shorten its lifespan, while deep discharges (below 20%) can also damage the battery.

Don't discharge the battery below 20% of its capacity. Discharging the battery below this level can damage the battery.

Do lithium batteries last longer if not fully charged?

LiFePO4 batteries do last longer if they are not fully charged. This is because LiFePO4 batteries are less susceptible to damage from deep discharges than other types of batteries. Deep discharges are when the battery is drained to a low level, such as 20% or below. Deep discharges can damage the battery's internal chemistry and shorten its lifespan.

It is best to keep LiFePO4 batteries charged between 20% and 80% of their capacity. This will help to prolong the battery's lifespan and ensure that it performs well.

Not letting your LiFePO4 battery run down completely will extend the battery lifespan. If you are preparing to store your batteries for a period of time, make sure you do so at half charge. Unlike other types of batteries that need to be recharged throughout their storage time, lithium batteries do better at 40%-50% DOD (depth of discharge).

How much does lithium battery degrade if left fully charged?

LiFePO4 batteries can degrade if left fully charged. The amount of degradation will depend on a number of factors, including the battery's age, the temperature, etc.

A study by the University of California, San Diego found that LiFePO4 batteries that were left fully charged for 6 months lost about 2% of their capacity. The study also found that the batteries that were left fully charged at higher temperatures lost more capacity than those that were left fully charged at lower temperatures.

Whereas, according to battery-testing firm Cadex Electronics, a fully charged lithium-ion battery will lose about 20% of its capacity after a year of typical storage. Increase the temperature to just above 100 degrees in a hot attic, or garage for example and that number drops to 35%.

It is generally recommended to store LiFePO4 batteries at a charge level of 50-70%. This will help to prolong the battery's lifespan and ensure that it performs well.