Do you know any ways to charge lithium batteries?

1. Linear charging method for lithium battery When the charger input voltage is greater than the open circuit voltage of the full overflow cell plus full headroom, it is best to use the linear method, especially when the 1.0C fast charging current is not too much larger than 1A. For example: MP3 players usually have only one lithium battery cell with a capacity ranging from 700 to 1500mAh, and the open circuit voltage at full charge is 4.2V. The power supply of the MP3 player is usually an AC/DC adapter or a USB interface, and its output is a regular 5V; at this time, a linear charger is the simplest and most efficient method. Examples of linear chargers-dual-input Li+ chargers and smart power selectors are dual-input USB/AC adapter linear chargers with built-in SmartPowerSelector for portable devices powered by rechargeable single-cell Li+ batteries. The charger integrates all the power switches required for charging the battery and external power supply and switching loads, so no external MOSFET is required: MAX8677A is ideal for portable devices, such as smart phones, PDAs, portable multimedia players, GPS navigation devices, digital cameras, And the digital video camera MAX8677A can work under independent USB and AC adapter power input or under either input of two inputs: When connecting an external power source, the intelligent power selector allows the system to not be connected to the battery or can be connected to a deep-discharged battery. The intelligent power selector automatically switches the battery to the system load, uses the unused input power part of the system to charge the battery, and makes full use of the limited USB and adapter input power. All necessary current test circuits, including integrated power switches, are integrated on the chip. The DC input current limit can be adjusted up to 2A, and both DC and USB inputs can support 100mA, 500mA and USB suspend modes. The charging current can be adjusted up to 1.5A to support a wide range of battery capacity. Other features of the MAX8677A include thermal regulation, overvoltage protection, charging status and fault output, power supply monitoring, battery thermistor monitoring, and charging timer. MAX8677A adopts space-saving, thermally enhanced, 4mmx4mm, 24-pin TQFN package, and is specified to work in the extended temperature range (-40~+85℃) 2. The Buck (step-down) switch charging method of lithium battery is 1.0C When the charging current is greater than 1A, or the input voltage is much higher than the full overflow open circuit voltage of the cell, Buck or step-down is a better choice. For example, in the hard disk-based PMP, a single-cell lithium battery is usually used, the full open circuit voltage is 4.2V, and the capacity ranges from 1200 to 2400mAh. At present, PMP is usually charged with a car kit, and its output voltage is between 9V and 16V. The relatively high voltage difference between the input voltage and the lithium battery voltage (minimum 4.8V) will reduce the efficiency of the linear approach. This low efficiency, coupled with a 1C fast charging current greater than 1.2A, will cause serious heat dissipation problems. In order to guard against this situation, it is necessary to adopt Buck method 3. SEPIC (boost and buck) switch charging method of lithium battery. In some devices that use 3 or 4 lithium ion/polymer batteries in series, the charger The input voltage is not always greater than the battery voltage. For example, a laptop computer uses a 3-cell lithium battery pack, the full-charge open circuit voltage is 12.6V (4.2V×3), and the capacity ranges from 1800mAh to 3600mAh. The input power supply is either an AC/DC adapter with an output voltage of 16V or a car kit with an output voltage between 9V and 16V. Obviously, neither linear nor Buck can charge this battery pack. This requires the use of the SEPIC method, which can work when the output voltage is higher than the battery voltage, and it can also work when the output voltage is lower than the battery. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Analysis of charging methods for power lithium batteries