Its been less than a year...most likely 7-8 months since i got my new yellow top, and lately my car has a real weak start. The cranking will be very weak if i let the car sit for a day or two, and when i start it back up after a short drive to run some errands, it will still have a very weak crank. The only time i get a strong crank is when i turn the AC and radio off and drive a bit, then start it up. I have the UR underdrive pulley if that makes a difference and i also have a 500 watt stereo. I think it may just be the killer 100+ degree weather making the AC work really hard, but i have to use the AC when it is this hot. My alternator passes the charging test at inspection a month ago so i don't think it is that...my battery is still under warrante so should i go have it checked out?

 

Underdrive pulley with a stereo system = for the battery.

The yellow top is not able to handle that; it has to be fully recharged. Actually most batteries can't handle your setup without premature failure.

You can try the redtop which does not have the inherent issue of the yellowtop or get the Exide Orbital.