Quote:
Originally Posted by mjhcobra
If bigger is always better is the main reason, then I get it, but there is such a thing as overkill. You start to suck HP away after 95 amps or so.
I don't see a difference in my Cobra and a 65 T-bird with the same motor but has accessories out the ass and a 55 amp alternator. Worked then, why not now?????
|
As far as sucking HP, that's a not exactly right......an alternator will only supply amps to the battery as needed. If you are cruising down the highway with nothing on,so to speak, your battery drain would be your ignition system and fuel pump (assuming an electrical fuel pump), amp draw would be small, therefore the alternator would not be "working hard" to replenish your battery, the more electrical current used, the more amp draw on the alternator,hence the more required to turn the alternator.......
A battery in good condition, fully charged will not tax the alternator much, HP draw is estimated at 1 to 2 hp!!!!!!!!!!! A weak battery would require more from the alternator, estimates are 3 to 4 hp.....either way, you'll never notice this!!!!!!!!!!!!!
Years ago, I had a camp in the woods with no electricity, we used a gaint battery (from some sort of industrial machinery, took 2 people to carry it) for the 12volt lighting system we had. The battery would last a weekend if you were careful, got tired of hauling back and forth home to charge it, so I took a 70amp GM alternator and mounted it on a homemade frame with a 3hp Briggs lawnmower engine to turn it. It would easily charge up a dead auto battery with no problems, but the big battery would kill the 3 hp motor when it had been used for a weekend, swapped out to a 5hp Briggs and it would easily re-charge the big battery.... The industrial battery was about 3 times the size of a standard auto battery!!!!!!!!!!!!!!
I used that homemade battery charger for years and when I sold the camp, I gave it to the new owner.....
If you have a 55/60 amp alternator, it'll do the job, it'll just have to work harder for a longer time to do the job, and subsequently build up more heat in it doing its job.....start any car and put on the A/C and other accesories for a few minutes and then go put your hand on the alternator case, I've done it, it'll be soo hot, you will not be able to hold you hand on it for more than 2 or 3 seconds, the alternator is working hard....higher amp units have higher output/capacity and don't have to work as hard as long......
Either alternator will do, larger just does it with less effort.......
David