Lookign for a little help. I have 2 batteries for my cheapie cordless drill but the charger died long ago and was tossed. I am trying to figure out what to do but I cant figure out this battery. I took it apart and it has 15 C size Ni-cad in there to get me to 18V but it has 3 contacts for charging. On top it says + and - but what the heck is that 3rd one. I checked with my meter it for sure is - but what the heck is that chip that its connected to?? The one in concern is colored blue. I can get a cheap setup again and use the charger form it and have a bunch of other extras but will it work?? It looks identical and I am sure it will fit in the only difference I see is the that 3rd contact.

Its the flux capacitor contact. Use it wisely my friend.

I think it's a temperature sensor for fast charging. Dont take my word for it though, thats just my best guess.

flux capacitor thanks for the help on that one I dont think its a temp sensor because it has a contact on the charger and the battery, but it doenst have one on the drill. I have no idea and its late where I am so I think its really late and everybody has gone to bed. Hopefully answers in the morning.

I have no idea, but isn't the temp thing NinHowFritz mentioned to do with temperature while charging, which would presumably mean that the contact would be on the charger and not on the drill?

Found some more information about the 3rd contact

"Two-prong polarized plug with three-prong contact"

I get a voltage reading when on the positive side and on this 3rd contact just as if I were on the regular + and -

I guess it could be a temp thing but I have no idea.

Maybe its built to suit various models that utilise the 3rd contact over one of the others.

It's a temp sensor for charging.

DJ

Yep, ignore the third terminal. I suggest investing in a "smart" charger and researching proper care and feeding of rechargeables.

Check out this site: http://www.rcbatteryclinic.com/welcome.htm

I'm thinking this would be the perfect opportunity for a new cordless set....

"Well Honey, they dont make this model charger anymore. Im thinking I should go with a long lasting brand this time."

It is on the charger and the battery and not on the drill. So that makes sense. I think I am just goiong to buy another cheapy one that comes with all the extras (saw sander drill) and use the charger and the one battery for it for everything I think my old batteries are still good so the new charger should charge my old batteries.

Yup temp. my DeWalt has the same thing. When you use the drill alot, the batt gets hot, and if you were to do a quick charge while hot, it runs the risk of bursting, or damaging the battery. So the third tab is so your charger "knows" the temp of the batt it's trying to charge, and knows if it is allowed to charge the batt, or if it's too hot to be charged.