Dewalt batterys

[kevplumb]

hi folks
anybody know what the black wire is for in dewalt 18v batterys
methinks temp sensor but not sure what for
i noticed while recelling an older one it didnt have one fitted
any help greatfully accepted
thanks
kev

 

[Burnerman]

What fettle Kev
It maybe a tapping to show how much juice is in the battery pack, and therefore how long before a charge is due maybe?
John

 

[motorbiking]

Is the old one a NiCd and the new one a Li-ion? It might be a balance circuit?