Yes, definitely set the charger to the Pb (lead) setting. I've charged many Power Wheels 6v & 12v batteries over the years with my "RC" battery charger; not to mention the battery in my full sized truck also. The overnight charger thing just wasn't cutting it for me or my kids. Depending on how fast you want to charge your battery will determine what amperage you want to use. Having used an 80's huge clunker automotive charger (borrowed) to do the work, before I acquired my LiPo/multi chemistry chargers in 2010, there were only two settings on the "automotive" battery charger...2amps and 6amps. That being said, I've never gone over 6 amps when charging my Pb batteries, and that was when my truck wouldn't start; I was in a hurry to get to work
. If unsure, a conservative setting is usually better for the longevity of the battery. The Power Wheels batteries I only charge @ 1~4amps with having checked the first couple of times to be sure they were not getting warm during charging. A 6v Pb battery peak voltage, at the end of charge, should be around 7.3v, and a 12v Pb battery will be around 14.7v after a peak charge.