Right! a larger capacity simply means it would take longer to fully recharge when dead but can run longer as well without a charge. If it takes a 1.2 amp hours (Ah) to start a car (a 5 sec starter burst) the charging system simply has to account for this loss of 1.2 Ah of say 100 total Ah so in normal situations the total size of the battery shouldn't matter.

-Gun

 

Hey just to add on from the original thread, I had the same problem with my lights pulsing and my guage bouncing all over the place and jumping up to 17 volts for a while. So I went to Autozone and picked up an electronic regulator for $14 and the volts are steady as can be now. No pulsing, no jumping. Its amazing what a simple part can do.