First, the correct way to charge a lithium battery:
Lithium is chemically very reactive and easily combustible. When the battery is discharging and charging, the internal temperature of the battery continues to rise. The gas produced during the activation process expands, increasing the internal pressure of the battery. When the pressure reaches a certain level, if there are scratches on the outer casing, it will rupture, causing leakage, fire, or even explosion.
1. Charging:
The safe operating voltage range for lithium batteries is 2.8~4.2V. Below or above this range, the lithium ions in the battery become very unstable, potentially causing accidents. To ensure the battery operates within this safe range, a dedicated charger is required. These chargers automatically adjust the charging method based on the battery's current state.
2. Activation:
Before the charger starts charging, it 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.
3. Constant current transformer 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.
4. Variable current constant voltage charging:
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 it detects that the battery voltage is still rising even when the charging current is less than 0.1A.
Second, the storage voltage of the model lithium battery.
Model lithium batteries are generally lithium polymer batteries, with a minimum safe operating voltage of 3.6V. However, to prevent damage from over-discharge, the minimum safe operating voltage is typically 3.7V, and the maximum charging cut-off voltage is 4.2V. At the highest voltage, the battery stores its peak energy. If the battery is kept at a high voltage for an extended period without use, gas generated from the reaction within the lithium battery cells will accumulate, eventually causing the battery to swell, commonly known as "bulging." To avoid this, the storage voltage of model lithium batteries is generally controlled between 3.7 and 3.8V.
Third, lithium battery storage conditions
The most critical storage conditions for model lithium batteries are temperature and humidity. Generally, room temperature has little impact on the state of lithium batteries, but they should not be exposed to direct sunlight. High temperatures can easily cause model lithium batteries to swell or explode. Therefore, model lithium batteries are usually stored in light-proof and airtight metal or plastic boxes. If a single model lithium battery has very good discharge performance, it is also necessary to purchase a model lithium battery explosion-proof protective bag. This reinforced bag has a reinforcing mesh inside, which can prevent high-energy model lithium batteries from damaging other items in the event of a gas leak or explosion.
