LiFePO4 chemistry lithium cells have become popular for a range of applications in recent years due to being one of the most robust and long-lasting battery chemistry available. They will last ten years or more if cared for correctly. Please take a moment to read these tips to ensure you get the longest service from your battery investment.
Tip 1: Never over charge/discharge a cell
The most common causes for premature failure of LiFePO4 cells are overcharging and over-discharging. Even a single occurrence can cause permanent damage to the cell, and such misuse voids the warranty. A Battery Management System is required to ensure it is not possible for any cell in your pack to go outside its nominal operating voltage range.
In the case of LiFePO4 chemistry, the absolute maximum is 4.2V per cell, though it is recommended that you charge to 3.5-3.6V per cell, there is less than 1% extra capacity between 3.5V and 4.2V.
Over charging causes heating within a cell and prolonged or extreme overcharging has the potential to cause a fire.
Over charging may occur as a result of：
- Lack of a suitable battery management system
- Faulty of infective battery management system
- Incorrect installation of the battery management system
At the other end of the scale, over-discharging can also cause cell damage. The BMS must disconnect the load if any cells are approaching empty (less than 2.5V). Cells may suffer mild damage below 2.0V, but are usually recoverable. However, cells which get driven to negative voltages are damaged beyond recovery.
Tip 2: More precautions for LiFePO4 batteries charging
- NEVER charge LiFePO4 batteries with a charger not specifically compatible with LiFePO4 batteries!
- When the cell is first used, it MUST be fully charged and discharged for activating it and giving fully capacity.
- Always charge LiFePo4 batteries in an area with adequate ventilation.
- No matter what charge mode the battery is in, stop charging once the cell temperature exceeds the absolute charge temperature range.
- No matter what charge mode the battery is in, stop charging once the cell voltage exceeds the absolute charge voltage.
- When the LiFePO4 batteries are intended to be stored for a prolonged period of time (more than one month), the SOC of cells should be adjusted to around 50% periodically(every three months is recommended).
Why you should charge the LiFePO4 battery to full capacity before the first use？
The LiFePO4 cells and batteries MUST be charged to full voltage level for activating it before assembling into a pack and before starting to be used. This way the cells will be fully charged and balanced before the first use of the battery pack.
Even in simple installations, it is important to make the first charging. Additionally to the first installation, we recommend to checking the cells of the battery pack from time to time and making the full balancing of all the cells, by means of the individual charging.
Tip 3: Clean your terminals before installation
The terminals on top of the batteries are made from aluminium and copper, which over time builds up an oxide layer when exposed to air. Before installing your cell interconnectors and BMS modules, clean the battery terminals thoroughly with a wire brush to remove oxidation. If using bare copper cell interconnectors, these should be cleaned too. Removing the oxide layer will greatly improve conduction and reduce heat buildup at the terminal. (In extreme cases, heat buildup on terminals due to poor conduction has been known to melt the plastic around the terminals and damage BMS modules!)
Tip 4: Charge frequently and shallower cycles
With lithium batteries, you will get longer cell life if you avoid very deep discharges. We recommend sticking to 70-80% DoD (Depth of Discharge) maximum except in emergencies.
Tip 5:How to store and maintain lifepo4 batteries during winter?
You can take a few different steps to maximize the life of your lithium batteries during the cold winter months, including:
- Storing them in the proper temperature: Keep your lithium batteries in a place that does not get colder than 32 degrees Fahrenheit or warmer than 80 degrees Fahrenheit.
- Charging them regularly: Ideally, lithium batteries should never be completed uncharged, so it’s important to remember to charge your batteries in the winter months when they are most prone to quick loss of power.
- Cleaning them: Corrosion and dirt can cause the battery to lose charge faster, which decreases its lifespan, so it’s important to keep your lithium batteries clean. You can use a mix of water and baking soda for a gentle cleaning.
Tip 6: Safety Precautions
- It is strictly forbidden to immerse the battery in seawater or water. When not in use, it should be placed in a cool and dry environment.
- It is strictly forbidden to reverse the positive and negative poles to use the battery.
- It is forbidden to use metal to directly connect the positive and negative electrodes of the battery to short circuit.
- It is forbidden to transport or store batteries together with metals, such as hairpins, necklaces, etc.
- It is forbidden to knock or throw, step on the battery, etc.
- It is forbidden to directly weld the battery and pierce the battery with nails or other sharp objects.
- It is forbidden to use or place the battery under high temperature (in the hot sun or in a very hot car), otherwise it may cause the battery to overheat, catch fire or fail to function, and shorten its life; the recommended temperature for long-term battery storage is 10-45°C.
- It is forbidden to throw batteries into fire or heaters to prevent fire, explosion and environmental pollution; scrapped batteries should be returned to the supplier or battery recycling point for disposal.
- Do not use it in places with strong static electricity and strong magnetic fields, otherwise it will easily damage the battery safety protection device and bring unsafe hidden dangers.
- If the battery leaks and the electrolyte enters the eyes, do not rub it. Immediately rinse the eyes with clean water and send them to the hospital for treatment, otherwise the eyes will be hurt. If the battery emits odor, heats up, discolors, deforms, or has any abnormality during use, storage, or charging, immediately remove the battery from the device or charger and stop using it.
- It is forbidden to insert the positive and negative poles of the battery directly into the power socket, and a special charger for lithium-ion batteries must be used.
- Before installation, check the battery voltage and connectors, and use it only after everything is normal.
- The battery is stored in half power. If the battery has not been used for three months, it needs to be recharged once.
- If the electrode is dirty, it should be wiped with a dry cloth before use, otherwise it may cause poor contact and function failure.