In the use of lithium batteries, it should be noted that after the battery is placed for a period of time, it enters a dormant state, at which time the capacity of the lithium battery manufacturer for emergency power supply is lower than normal, and the use time is also shortened. However, lithium batteries are easy to activate, as long as 3-5 normal charge and discharge cycles can be activated to restore normal capacity. Due to the characteristics of the lithium battery itself, it has almost no memory effect. Therefore, the new lithium battery in the user's mobile phone does not require special methods and equipment during the activation process.

To charge lithium-ion batteries, use a dedicated lithium-ion battery charger. Lithium-ion battery charging using the "constant current/constant voltage" mode, the first constant current charging, to the emergency power supply with lithium battery suppliers near the termination voltage changed to constant voltage charging. For example, a battery with an 800mA.h capacity has a termination charge voltage of 4.2V. The battery is charged at 800mA (charging rate is 1C) constant current, and the battery voltage rises with a large slope at the beginning. When the battery voltage is close to 4.2V, it is changed to 4.2V constant voltage charging, and the lithium battery current gradually drops, and the voltage changes little. When the charging current drops to 1/10C (about 80mA), it is considered that the price of lithium battery for emergency power supply is close to full. You can terminate the charging (some chargers start the timer after 10C, and end the charging after a certain time). Lithium-ion batteries (although the rated voltage is the same, 3.6V) can not be charged with a nickel-cadmium battery charger (charged with three nickel-cadmium batteries), because of the different charging methods, it is easy to overcharge.

② Charging voltage: The termination charging voltage when fully charged is related to the negative battery material, coke is 4.1V, and graphite is 4.2V, generally known as 4.1V lithium-ion batteries and 4.2V lithium-ion batteries. When charging, it should be noted that the 4.1V battery cannot be charged with a 4.2V charger, otherwise there will be a risk of overcharging (the charger IC used for 4.1V and 4.2V chargers is different). Lithium-ion battery charging requirements are very high, it requires a sophisticated charging circuit to ensure the safety of charging. The accuracy tolerance of the termination charge voltage is ±1% of the rated value (for example, the tolerance of a 4.2V lithium-ion battery is ±0.042V), and overcharging can cause permanent damage to the lithium-ion battery.

(3) Charging current: The charging current of lithium-ion batteries should be based on the recommendations of the battery manufacturer, and require a limited current circuit to avoid overcurrent (overheating). Generally, the commonly used charging rate is 0.25 ~ 1C, and the recommended charging current is 0.5C (C is the capacity of the battery, such as the nominal capacity of 1500mA.h battery, charging current 0.5*1500=750mA). The battery temperature is often detected during high current charging to prevent damage to the battery or explosion due to overheating.

④ Charging temperature: When charging the battery, its ambient temperature cannot exceed the temperature range listed in the product characteristics table. The battery should be charged in the temperature range of 0 to 45 ° C, away from high temperature (above 60 ° C) and low temperature (-20 ° C).

If the lithium-ion battery is overcharged, overdischarged or overcurrent during charging or discharging, the battery will be damaged or the service life will be reduced. For this purpose, a variety of protection elements and a protection circuit composed of a protection IC are developed, which is installed in the battery or battery pack, so that the battery can obtain perfect protection. However, overcharge and overdischarge should be prevented as much as possible in use. For example, during the charging process, the mobile phone battery should be separated from the charger in time when it is nearly full. When the discharge depth is shallow, the cycle life will be significantly increased. Therefore, when using, do not wait until the battery is insufficient on the phone to charge, let alone continue to use this signal, although there is still a part of the residual capacity available when this signal appears.