I have had a single battery. I'm going to install the Blue Sea Add A Battery. I'm also doing some stereo upgrades along with it. My question is will 2 batteries be enough. I will have 3 amps hooked up. I don't sit and listen to the radio for more than an hour. I am usually out wake boarding or surfing. Here are the amps I have.

Kenwood KAC-7205 powering my sub.

A JL XD600/6 for the cabin speakers.

And a JL400/4 for the Rev 10's

I was thinking of running (2) group 27's, will that be sufficient? I'm new to all this stuff so let me know what you guys think.