Before reaching the user, lithium iron phosphate batteries may have been stored in a warehouse for a period of time, and after this period, they may enter a dormant state, requiring activation. Activation can be achieved through 3-5 normal charge-discharge cycles.
Due to the inherent characteristics of lithium-ion batteries, they have virtually no memory effect. Therefore, users do not need special methods or equipment to activate new lithium-ion batteries. The best approach is to use the standard charging method from the beginning for natural activation.
Normal charging use
Before charging begins, the charger supplies a small current to the battery while simultaneously detecting changes in battery voltage, and gradually increases the current until it reaches the set value. This process can be considered an activation or test charging.
The charger charges the battery with a constant current. As the battery voltage increases, the charger simultaneously increases the charging voltage to speed up the charging process.
When the battery reaches the 4.2V cutoff voltage, it has only been charged to about 70% (not fully charged). At this point, the charger continues to charge the battery with a constant voltage and a gradually decreasing current, stopping charging only when the current is less than 0.1A and the charger detects that the battery voltage is still rising.
When charging lithium iron phosphate batteries and related products, it is best to use the original, dedicated charger. This is because the original charger is the most suitable in terms of voltage, charging speed, and other factors, and is least likely to damage the battery.
1. Some mobile phone chargers have built-in protection that stops charging when the lithium-ion battery voltage reaches 4.2 volts. My idea is to connect a slightly higher power silicon diode (with a forward voltage drop of about 0.6 volts) in series between the lithium iron phosphate battery pack and the charger. This way, when the lithium iron phosphate battery voltage reaches 3.6 volts, the diode voltage drop will add up to 4.2 volts, which the charger can detect and stop charging.
2. The protection circuit of the mobile phone battery was taken out and used for the charging protection of the lithium iron phosphate battery pack. It is based on the above principle and a diode is connected in series during charging to provide 4.2 volt protection.
3. Considering that the inconsistency between battery packs will gradually increase when a single cell is charged in series, in order to ensure the battery life, the only way is to reduce the utilization rate of the lithium-ion battery pack and perform equal charging. As an effective way to reduce the inconsistency of battery pack characteristics, it can balance the characteristics of the batteries, thereby improving the utilization rate of the iron phosphate battery pack and significantly extending the battery pack life.
4. The optimal charging temperature for lithium iron phosphate battery packs is between 0-45℃. This temperature range is more conducive to the activation of the chemical properties within the lithium-ion battery pack, resulting in higher charging efficiency.
5. Charging is a crucial step in using lithium-ion batteries. Proper and reasonable charging greatly extends the battery pack's lifespan, while rough and haphazard charging will significantly impact battery life. For lithium iron phosphate battery pack chargers, it is best to use the dedicated charger provided by the manufacturer. Do not use other models or chargers with incompatible charging voltages.
Calculation method for charging and discharging lithium iron phosphate battery packs:
First, let's talk about charging: The charging process of a lithium-ion battery pack is like filling a bucket with water; the time it takes is the only factor. The larger the tap, the faster it fills. Similarly, charging a battery depends on the charging current; the higher the current, the shorter the charging time!
