You obviously come from a very technical background, and I respect that, so this is not intended to be a shot - but I will politely disagree with that last post on several notes.
While many gel cells have a lower than average life expectancy, that is usually because they are used in an application where they are constantly deep-cycled. Used in a car system where they will have a constant source of power, however inadequate, they last a VERY long time. The new drycell units use a better version of gel technology, and are even better. I personaly have a 4 year old Redtop that has been through 3 cars and 2 large systems with stock alternators, still strong. Also note - systems of the power discussed here shouldn't and usually don't play all the time at anywhere near full power, so the alternator has ample oppourtunity to "catch up" on charging the batteries.
I'll leave the fume issue alone, the point is made regarding non sealed batteries in any enclosed area. Anyone dumb enough to do so deserves what they get!! (J/K - sorta!)
I dunno where you get your info about power and speakers, all I can say is, 300 watts and 150 db? Unless you're using something other than a regular transducer in some magical enclosure - good luck! Running amps that claim 300 watts and put out 1200 doesn't count, either. I have seen ridiculous SPL #'s posted from single subs off comparably moderate power, but they use crazy huge TTL enclosures the likes of which are not anything like practical, even for most competition systems.
I personaly have three customers currently hitting between 150 and 155, the most "efficient" of which has around 1600 very real watts running 2 15" subs in vented chambers. Stock 115 amp alternator, dual batteries, 153 Db. Upgraded alternator is coming for that one. The other two are both running 200 amp alternators and dual batteries, one of them just over 2000 total watts to two 15's, the other a little over 3K to four 15's. Not one of them has blown a sub yet, two of the systems are well over 6 months old. I have a guy in NY who is still using the original 12" woofers I installed in 1995, running about 500 watts, now hitting around 139 - down from the 142 he posted when the setup was new.
On the cap issue, all I have to say is charge one up, get your hand wet, and smack the terminals. Keep me posted on the results.
I agree with you on the large scale view of things. By and large, electrical systems in cars are not strong enough to run a high power audio system - that's why I started this thread in the first place. And I see lot's of people trying to add power that just isn't there, in situations where more power isn't what they need anyway. This is another issue I am trying to address with this and other info threads. I just dunno where you get some of your #'s - 10 years of real-world experience in this industry leaves me disagreeing on a few things.
