Im building a new car Audio set up and I have a dual in dash dvd player radio with a 1800 watt mono block for my subs and a sony 4 channel amp to power my door speakers and tweeters right now I am running my stock alternator and a deep cycle motor under the hood. Im having my system professionally installed by a local shop and he says my charging system isn't going to be enough he said he would install a 2nd battery in my truck for about 150 bucks for the battery and install its a Kenitec battery the "cap killer' I was wondering if my stock alternator cant handle whats under my hood how is it going to help by installing a 2nd battery then wouldn't neither of them give me enough power. im just curious to know and suggestion would be nice but i dint want to change my alternator unless its Absolute necessary