What is a 18650 battery?
The number 18650 is the size of the battery. 18 means the diameter of the battery is 18mm, 65 means the length is 65mm and the last zero means that the battery is cylindrical.
Generally, there are three kinds of 18650 batteries: lithium-ion battery, lithium iron phosphate battery, and nickel-metal hydride battery.
The 18650 standard is a standard-shaped type of lithium-ion battery developed by SONY to save money in the early days, and it has been used ever since so that it has become a common standard.
Because lithium battery has better performance than nickel-cadmium battery and nickel-metal hydride battery in many aspects, so many products use a lithium battery, so what are the characteristics of this kind of battery?
Capacity is large: a lithium battery battery battery at least 1200mah more than, even to achieve 4500mah, and the general battery cell only about 500;
High energy storage efficiency, good stability: can store more capacity, and generally have internal protection circuit to prevent the battery from burning out;
(3) almost no memory effect: do not put the remaining power before charging, can be charged at any time, easy to use;
Charge and discharge cycle life is high: cycle times than the general battery;
Environmental protection, no toxic substances: non-toxic, harmless, no pollution, after RoHS quality certification.
Lithium batteries don't usually use root, but the dogan, together we often referred to as the batteries, the battery life often appear in the outside, such as our laptop battery, charging treasure, electronic digital products, printers, wireless devices, portable, intercom communications, POS machine lithium battery, etc, many currents of battery capacity is 2200 mah.
HOPPT batteries have four main protection functions:
Overcharge protection: when the lithium battery is overcharged, the temperature rise inside the battery will keep rising, increasing the detection system of battery voltage. When the overcharge voltage of the battery reaches a certain value or period, the overcharge function will take effect and automatically stop charging to protect the battery.
Over-discharge protection: over-discharge is the battery has been in the overload output state, generally have discharge protection, at this time the battery will be in static waiting mode;
(3) overcurrent protection: this overcurrent protection value can be adjusted, some things several amperes, according to the actual situation to choose the setting
(4) short circuit protection;
When the battery is short-circuited, the overcurrent ACTS to protect the battery from burning out.
In addition to these four protection functions, some also have a temperature, balance, and other functions, the battery generally built-in PCM protection system, with multiple protection functions.
The general charging process of lithium battery:
This process can be divided into three stages: the first stage is trickle charging. When the battery is lower than a certain value, such as 3V, a constant current of up to 0.1c can be used to charge the battery.
In the second stage of constant current charging, when the voltage reaches a certain value after trickle charging, constant current charging is adopted. As shown in the table below, the charging speed can be changed to 0.5c constant current charging.
The third stage constant voltage charging, due to the lithium battery voltage is not too high, so at this point to constant voltage charge, when the very slow to charge can default have been charged at this time, set the time, but the actual situation, set up, this setting are usually set a limit, that is to say, regardless of is, when we charge it for a long time will think is full of, this is the protection of the battery.