Do you know why phone battery has three contacts?

Do you know why phone battery has three contacts?

Recently, a friend asked an interesting question. The mobile phone battery generally has at least three contacts. The ordinary 5th battery has only two contacts, positive and negative, while mobile phone battery has three. Why? The manager of this industry explains this phenomenon below.

Manager Liu said that in fact, the electrode of the mobile phone battery is the detection pole of the battery protection board, which is used to detect the state of the battery, and is convenient for automatically protecting the battery and the mobile phone. Most cell phone batteries have three metal shocks, positive, negative and identification resistor contacts.

In addition, some mobile phone batteries now have four metal contacts, such as HTC's mobile phone battery. The contact on battery is a negative temperature coefficient thermistor, which also use on battery protection board to suppress excessive current in circuit and protect the battery of mobile phone. In short, it is mobile phone battery that has some protection modules, so there are three or four contacts.

The page contains the contents of the machine translation.