I want to set up a small track at the local street market in our town using a C7042 APB running 6 magnet cars and 3 lane changers. At such events I make an easy track and turn the power down to 75% or 50% so the kids can mash the throttle and the cars stay on. This is a new event coming up and the organisers will not supply power. "Bring your generator and testntagged power cord" they say. I have neither so I'm wondering if it's practical to run my power base off my 12V car battery. The event goes for 4 hours and my car battery says "40Ahr". If not my car battery, I might be able to borrow a deep cycle battery... Advice please.