Why does a mobile phone battery have three contacts?

The mobile phone battery generally has at least three contacts, but the regular 5th battery has only two positive and negative contacts, while the mobile phone battery has three, why?

Recently, a friend asked an interesting question. The battery of a mobile phone generally has at least three contacts, but the normal 5th battery has only two positive and negative contacts, while the mobile phone battery has three. Why is this? So only professionals can help answer. The following industry manager Liu will explain this phenomenon for everyone.

Manager Liu said that in fact, the contacts of the mobile phone battery are the detection electrodes on the battery protection board, which are used to detect the status of the battery and facilitate the automatic protection of the battery and the mobile phone. Most cell phone batteries have three metallic shocks, positive, negative, and identification resistor contacts.

In addition, there are still some cell phone batteries that have four metal contacts, such as the HTC cell phone battery. The more contacts on the battery are negative temperature coefficient thermistors, which are also on the battery protection board to suppress excessive current in the circuit and protect the cell phone battery. In short, it is the mobile phone battery that incorporates some protection modules, so there are three or four contacts.