I've run a 4 lane track at a school fete all afternoon on a car battery without flattening it, so I don't see a problem with a battery to run 1 car at a time (time trial) one and off throughout a day.
Cars only take maximum current for a very brief period when accelerating from rest. The average is far more important if you want to know how long before the battery goes flat. The peak current for a scalextric car is about 2 amps, but it only takes that much for such a brief period that it doesn't record on a normal meter. As you say, there are lots of variables that can change the average, as a ball park figure half an amp average should be somewhere near. Half an amp for 8 hours is only 4 amp hours, so even quite a tired car battery will manage that easily
P.S. Just seen Greg's post - indeed a fuse or circuit breaker would be a wise precaution if running off a battery. 2 amp rating will give your one car all it needs and protect against shorts.
Cars only take maximum current for a very brief period when accelerating from rest. The average is far more important if you want to know how long before the battery goes flat. The peak current for a scalextric car is about 2 amps, but it only takes that much for such a brief period that it doesn't record on a normal meter. As you say, there are lots of variables that can change the average, as a ball park figure half an amp average should be somewhere near. Half an amp for 8 hours is only 4 amp hours, so even quite a tired car battery will manage that easily
P.S. Just seen Greg's post - indeed a fuse or circuit breaker would be a wise precaution if running off a battery. 2 amp rating will give your one car all it needs and protect against shorts.
