I have a number of 4 cell, 4.8V NiMH mobile phone batteries that I want to string together to make a larger battery pack. When I pull one apart, I find that the centre of the three terminals on the case is the positive, the other two are straight negative, and negative with a very small component in the lead about 1mm in diameter and a few mm long. The voltage reading between pos and straight neg is
5.19V and between pos and this other neg with the unknown component is
5.13V. Can anyone tell me what this strange (to me) component is? Perhaps a diode, for charging purposes? Thanks for any help, regards, John