A group of 6-string 18650\150mah-3c battery pack (25.2V 4.5A), the batteries are stored for more than 5 days, and the non-voltage batteries are selected for spot welding and protection board combination. Within 12 hours, one of the six batteries in the battery pack dropped from normal voltage to 0V, and the ratio reached more than 5 percent. After leaving the factory, customers will find such battery packs one after another.
Questions: 1. Before the battery cells are grouped, the sorted bad battery cells can drop a maximum of 100mV (about one-thousandth), and the battery cells we use are within 10mV, why 12h after the group Can the normal voltage drop to 0V?
2. How should I proceed to analyze the cause of the cell or the protection board?
Billie Veröffentlicht am July 14, 2020
First determine whether the number of strings that will fall to 0V will be in the same string. Personally think that the protection board is likely.
Blaise Veröffentlicht am July 14, 2020
There is only one tandem for a total of six.
Nathalia Veröffentlicht am July 14, 2020
There may be a problem inside the battery. The protection board is good or bad. Try changing the battery pack.
