Originally Posted by brucemac
how many amps? how much total RMS? i wouldn't mess with your alternator unless absolutely necessary. i'm running 2 amps rated at total 1500W RMS with the stock 03 70A alternator and two optima blue tops and so far it doesn't look like i'm going to need to change my alternator. it would be better, imo, to add a 2nd or possibly 3rd battery and isolator along with a good muli-bank smart charger that you could charge the house bank off the water. good marine grade alternators are pretty expensive. the balmer 150A units that some here run cost over $800.
Are you haveing any voltage loss with your 70A alternator. I did an upgrade on my system in the previous months and am only running about 1000W RMS on a 75A alternator. Hasnt had any issues yet, but it is very much in the back of my mind..... Any issues with yours?