The 3300A figure is what the battery can put out for a very short burst of current - relevant for the intended use of driving high-power audio systems, but much less so for electric bikes. The battery is also rated with a capacity of 67 A-hrs which is more relevant. At 12V, that gives about 800 W-hrs or the ability to drive a 1 HP motor for about an hour. Like other lead-acid batteries, they're rather heavy for the amount of capacity.