Juan, I dug through my old email and found some history.
I purchased this battery from you a couple of services ago, and I was sent the wrong one. I was supposed to send it back for replacement but it seems I just purchased another one locally and never actually returned it. That's why I have a Jet Central 9.9V battery!
I am glad because I was really wondering what could have happened, as the engine runs fine on 7.4V.
thanks, and sorry for the confusion!
David