The kids had an old F150 monster truck Power Wheels toy that had a dead battery. I charged the old 6 volt battery for about half of a day. After charging, it wouldn’t light up a test light, much less turn a motor in a big toy truck. I took an old car battery and installed the power wheels battery connector to the terminals of the car battery. I used a couple of ratchet straps to hold it down. The 12 volt car battery turns the 6 volt motor twice as fast. My youngest daughter loves it. She goes pretty much full throttle on it all the time. My oldest daughter likes it, but is very cautious. She pumps the pedal causing a surging that is almost sickening to watch. Thanks for watching! Please subscribe.