are powercell batteries any good for electric bikes,at 12v and 3300 amps thats 39600w 50 pounds is heavy,but they will give you distance.

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.