zero voltage or low voltage of the battery pack?

Q:What are the possible reasons for zero voltage or low voltage of the battery pack?

A:Single battery in the battery pack is zero voltage. 

Short circuit or open circuit of the connector or wrong connection. 

Desoldering or cold solder joint between the batteries and lead. 

Wrong connection between the batteries. 

There is desoldering or cold solder joint between the connection strap and battery. 

The wrong connection or failure of the electronic components inside the battery pack.

Q:What are the possible reasons for zero voltage and low voltage of the battery?

A:The outside short-circuit on the battery, overcharge, or over discharge. 

The battery is continuously over charged by the very high current. 

The battery is internally short-circuited or slight short-circuited.

23,What are the possible reasons if the rechargeable battery or rechargeable battery pack can not be charged?

The battery is zero voltage or there is battery with zero voltage in the battery pack.

 There is wrong connection inside the battery pack. There is abnormity of electronic components and/or PCB inside the battery pack. 

Failure in charger. 

Outer element causes the charging efficiency to be too low, such as extremely low or high temperature.