The correct way to charge lithium batteries and the charging process in detail

As a secondary battery, lithium batteries like mobile phones and laptops can be recharged many times and are easy to use. However, there are various claims and even misconceptions about the charging method of lithium batteries.

So, for new lithium batteries, how to charge them correctly? Hirsh gives you a collation of commonly used mobile phone lithium battery charging method, of course, know its right to know its right, the correct use of lithium batteries can not be separated from the understanding of the lithium battery charging and discharging process

The correct charging method for lithium batteries

1. Li-ion batteries, whether used or not, "shelf life" of 3 years, about 400-500 times after the decay very quickly. It depends on whether you first use the 3 years or first charge to the number of times. 2. lithium battery in addition to fear of low power, but also afraid of a point is overheating, especially when charging. If your phone case dissipates heat very poorly and gets hot when charging, it is best to take the case off while charging.

2. Shallow charging and discharging is ideal, that is, charging and discharging does not reach 100% of the maximum capacity of the battery, that is, charging is not full and discharging is not finished. Do not use the phone for a long time during the charging process to make it the longest life. 3. It is not recommended to play with the phone while charging, it should be safer to play while charging at half power (i.e. around 50%), if the internal temperature of the battery is high at full power, the heat will become bigger when playing with the phone and the battery temperature will be higher. High battery temperature will have a certain impact on the life of the battery.

Second, the lithium battery charging process is explained in detail

The most suitable charging process for Li-ion batteries can be divided into four stages: trickle charging, constant current charging, constant voltage charging and charging termination.

Stage 1: Trickle charge - Trickle charge is used to first pre-charge a fully discharged battery cell (recovery charge). The battery is first charged using a constant current of up to 0.1C when the battery voltage is below about 3V.

Stage 2: Constant current charging - when the battery voltage rises above the trickle charge threshold, the charging current is increased for constant current charging. The current for constant current charging is between 0.2C and 1.0C. The current during constant current charging does not need to be very precise, quasi-constant current is fine. In linear charger designs, the current often rises with the battery voltage to minimise heat dissipation problems on the transfer transistors. Charging at a constant current of greater than 1C does not reduce the overall charge cycle time and therefore this is not desirable. When charging at higher currents, the battery voltage rises more rapidly due to overvoltage of the electrode response and the rise in voltage across the internal impedance of the battery. The constant current charging phase becomes shorter, but the total charge cycle time is not reduced as the following constant voltage charging phase increases accordingly.

Stage 3: Constant voltage charging - When the battery voltage rises to 4.2V, constant current charging ends and the constant voltage charging stage begins. For optimum performance, the regulated voltage tolerance should be better than +1%.

Stage 4: Charge termination - Unlike nickel batteries, continuous trickle charging of Li-ion batteries is not recommended. Continuous trickle charging can cause a plate plating effect on lithium metal. This can make the battery unstable and may lead to a sudden and rapid automatic disintegration.
 

There are two typical methods of charge termination: using a minimum charge current judgement or using a timer (or a combination of both). The minimum current method monitors the charge current during the constant voltage charging phase and terminates charging when the charge current is reduced to the 0.02C to 0.07C range. The second method is timed from the start of the constant voltage charging phase and terminates the charging process after two hours of continuous charging.

The four-stage charging method described above takes approximately 2.5 to 3 hours to complete the charge of a fully discharged battery. Advanced chargers also employ additional safety measures. For example, if the battery temperature exceeds a specified window (usually 0°C to 45°C), then charging is suspended.

As can also be seen from the Li-ion battery charging curve graph, for each stage, we can not only use the Li-ion battery correctly, but also better protect it from improper handling that may cause damage.

Third, fast charging for convenience, slow charging to preserve life.

Apple lithium-ion batteries use fast charging to quickly reach 80% charge and then switch to a slower trickle charge. Depending on the settings and charging device, the time it takes to fully charge the first 80 per cent will vary.

When the battery exceeds the recommended temperature, the software may restrict charging after the charge has reached 80%. This combination of processes will not only get you out and about with your device faster, but will also extend the life of your battery.

Four: Make charging easier.

You can charge your Apple lithium-ion battery whenever you need to. Apple's lithium-ion batteries work on a charge cycle. If you use (discharge) up to 100 per cent of the battery's capacity, you've completed a charge cycle, but not necessarily with a single charge.

For example, you might use 75% of the battery one day and then fully charge the device overnight. If you use 25% the following day, then the total discharge will be 100%, thus completing a charge cycle cumulatively over two days.

It may also take a few days to complete a charge cycle. After a certain number of charges, the capacity of any type of battery will decrease. Lithium-ion batteries have a capacity that decreases slightly with the completion of each charge cycle.

Apple lithium-ion batteries will retain at least 80% of their original capacity after many charge cycles, depending on the product.