Tell me about the current situation. The allowed charging voltage is 4.2V, and the output limited low voltage is 3.6V. This is the national standard implemented by most mobile phone batteries, and there are many other details, such as the charging current limit. It is 200-300MA. There are also short circuit protection times etc, but that's all we can see. There is no single national standard for cell phone batteries. But I'm talking about what most companies do when designing cell phone batteries.
1. Voltage measurement method
That is, the battery power is obtained by simply monitoring the battery voltage. Advantages of this method: simplicity Disadvantages: imprecise, the precision of the power measurement is only greater than 20%. Especially when the battery charge is lowere at 50%, the calculation of the phone's power will become very imprecise. Battery protection by this method is therefore very limited.
2. Battery modeling method
This method involves creating a data table based on the battery discharge curve. The data table will show the power values at different voltages. Advantages: More accurate than the voltage test method. Disadvantages: Obtaining an accurate data sheet is not simple because the relationship between voltage and power also involves factors such as battery temperature, self-discharge, and aging.
Early developments of lithium batteries
Lithium batteries were first used in pacemakers. Lithium batteries have the advantages of extremely low self-discharge rate and gentle discharge voltage, enabling pacemakers implanted in the heart.human body to operate for a long time without recharging. Lithium batteries typically have a voltage rating above 3.0 volts and are best suited for use as an integrated circuit power supply. Manganese dioxide batteries are widely used in calculators, digital cameras and watches.
In order to develop more efficient varieties, various materials were researched to create unprecedented products.
In 1992, Sony successfully developed lithium-ion batteries. Its practicality has significantly reduced the weight and volume of portable electronic devices such as cell phones, laptops and calculators.