Another second battery thread. Sorry!

I know this has been discussed many times, and I've read the threads, but I still can't decide whether I need to add a second battery. I have a 55 amp alternator and a group 34 Optima blue top (the deep cycle one). I have a stereo that's 1040 watts in full song, and a ballast system with 4 ballast puppy's. We are always rushed, and our usual program is to start the boat, start the pumps, turn off the pumps 3000 pounds later, turn on the stereo, wakeboard, turn off the stereo, hit the pumps to empty, turn off the boat, and go home. So, my question is, can one battery keep up with all that? I've never had any problems in the past, but I added 550 watts to the stereo this off season, which has me concerned. I just don't want to be going down the creek with my gauges dimming to the beat of 50 cent. I've never put the battery on a charger afterwards but I certainly could. As always, thanks so much for any insight.

You can never have to much battery!!do it!! **** get 2 more

Every boat should have at least two batteries. First thing I did when I bought mine is add a Perko and second battery. If one goes dead its really hard to get enough speed to push start, unless everyone has flippers on . Maybe the better question is will your alternator keep up, and if its pulling +1000w the answer is no. Running voltage is about 14v . So 1040w divided by 14v gives a max current draw of about 74 amps. Music doesn't play at full tilt through an entire song with different bass notes etc fluctuating...So would your average draw be less than 50amps.... That I can't tell ya. . Also what an amp puts out is different than what it's drawing. If your amps are 80% efficient then to make 1040 watts its actually drawing 1300 watts from your bank. That would be 92 amps... So to It wouldn't hurt to upgrade to a 70 or 90 amp alternator though and add a second battery if you want to not worry about it. Otherwise keep a good booster pack on board just in case and invest in an onboard charger for when you get back but either way I'd add at least a second battery.

If you have to question it, you need it. A second battery is a life saver! Also get an onboard charger to keep them ready at all times, you won't regret it!

I just got an onboard this year and it seems to make life easy as can be. I paid like a bill for a 5/5 dual bank, took 15 min to install, and won't overcharge either bank

Thanks so much for the comments and suggestions. I really appreciate it. I've just put a ton of hours into working on the boat this spring and am getting a little tired of it. But, I guess I'll go ahead and add a second battery plus some type of isolator or switch (I'm looking at those threads now) plus an onboard charger. My 55 amp alternator is only a year old (what great planning by me!) so I'm gonna run it until it dies. With respect to the batteries, as I mentioned before I have a group 34 Optima bluetop, but it's new and I can still return it to the store. So . . . should I get a second group 34 to match the one I already have, or return the one I already have and go with two larger batteries, like two group 31's? I've always stuck with group 34 because that's what fits in the factory battery hole in the floor, but since I'm adding a second battery I'm tempted to just abandon the hole and put the two new batteries side by side in the compartment behind the observer's seat.

optima's are great starting batteries and they last forever, however they aren't the best for long running times. Also just read on optima's website that that battery is only 50 amp hours and not warrantied for deep cycle applications.. I found that for $86 the deep cycle/starting batteries at costco are hard to beat. group 27 rated for 115amp hours each. I have a 2200 watt system and have two for the stereo and one for starting.

Is this all you need? http://www.amazon.com/Perko-8501DP-M.../dp/B00144B6AE

Which one? http://www.perko.com/catalog/category/battery_switches/

What a price difference http://www.bonanza.com/listings/Perk...nect/105361255

Originally Posted by rexlex01

Is this all you need? http://www.amazon.com/Perko-8501DP-M.../dp/B00144B6AE

Which one? http://www.perko.com/catalog/category/battery_switches/

What a price difference http://www.bonanza.com/listings/Perk...nect/105361255

The less expensive one is rated at like 250 amps continous and the other is 380 amps. Also, I dont believe the cheaper one has alternator field disconnect...