Connection mode of battery in charging treasure

The internal batteries of most charging treasures are connected in parallel, and then the DC boost circuit is used to boost to 5V, which has the advantage of reducing the cost. Relatively speaking, the charge and discharge protection circuit cost of series lithium battery is better.

The two batteries on the other side of your battery are only connected to the negative electrode, and the positive electrode seems to be disconnected. There are two possibilities:

1. Don't worry when disassembling. The positive wires of the two batteries are disconnected, which may be directly welded to the PCB board, because the circuit board is very close to this group of batteries when it is installed in the box;

2. When installing the charging treasure, the staff forgot the welding wire. This kind of cottage charging treasure is mostly made by small factories or manual workshops, with poor workmanship and no professional quality control testing, so everything is in pursuit of low prices and profits.