How to Store Lithium LiFePO4 Batteries for Long Term

There are many types of lithium-ion batteries, but the most widely used are those with an iron phosphate chemical composition called LiFePO4 batteries. As compared to other lithium-ion batteries, these batteries have a high energy density, so they can store more electric charge for their specified weight. Unlike other lithium-ion batteries, LiFePO4 batteries are more temperature stable and are ideal for deep cycle use.
LiFePO4 batteries are widely used and preferred owing to their low self-discharge rates, low maintenance requirements, and high charge retention characteristics. These batteries are equipped with BMS meaning a battery management system that smartly protects the battery from overcharging and balances the cells. In addition, these batteries are sealed, so there won’t be any fumes that can cause pollution.
Many people store these batteries during the off-season when they are not in use, which makes them quite handy. The storing part is a bit tricky as you can enhance the useful life of these batteries by using good storage techniques or otherwise damage the internal structure of the battery by using improper storage techniques. Several questions have been raised about storing these batteries.

Can you store the LiFePO4 battery fully charged?

Storing a LiFePO4 battery with a full charge is recommended, as these batteries usually have a very low self-discharge rate of 2% per month. To ensure that no load drains additional charge and power from the battery, it should be disconnected from any attached load. For long-term storage, give the battery a charge of over 50%, and ideally keep it in a fully charged state for the greatest charge-retaining capacity during storage.
It’s important to remember that batteries naturally deplete even when staying idle in storage. If you keep your battery in a state of low or zero charge, then you could face serious repercussions. Over-discharging can lead to some irreparable damage, even when the battery is still under warranty. To avoid potential problems, it is recommended that you store the battery with a charge level of 50% or more.

How long can you store a LiFePO4 battery?

It is possible to store liFePO4 batteries for a short or long period of time. Generally, it is held 3-6 months, yet with careful measurements, it can even stay up to 3 years. It is important to take into consideration the 2% self-discharge rate of these batteries and therefore charging them to 50% or more before storing is recommended. Additionally, fully charging the batteries beforehand will help prevent over-discharge.
You should store LiFePO4 batteries at a low temperature, away from direct sunlight, in a dry and indoor space. It is recommended you store these batteries at a low temperature for a long period of time.
Maintaining the battery health is vital and, unfortunately, self-discharge is inescapable. Continuous long-term self-draining can have an effect on the LiFePO4 cell’s internal structure, so it should be recharged every three to six months at 3.8 to 3.9 volts. If you’re short on time, charging every six months will suffice.