jlbspd

I just installed a new cranking battery in my Baja Hammer. I also replaced the alternator with a new 70amp unit. My plans are to add an additional battery to help keep up with the stereo system (two marine amps, subwoofers, multiple mids / hi seperates). I know before I added a new battery and alternator, it didnt take much time until the battery was screaming to start the motor after listening to the stereo.
Any suggestions on the best way to do this? What about manual vs. auto battery switches? hate to add the additional weight of a battery but what am I to do for good loud music lol

US1 Fountain

iTrader: (1)

Very simple. Use a Blue Seas battery combiner. It'll take care of making sure it's charged w/o any input from you, and don't need to mess with switches. Connect your stereo to the 2nd battery.

Easiest to wire up and better than the traditional old school isolators.

the deep

iTrader: (8)

Could you tell a brother where one would purchase a Blue Seas battery combiner . I have never heard of these but certainly like the concept . This isn't like E3 spark plugs is it.........

ChargeIt

I have run combiners in the past and burned up two rated for 90 and 120 amps.
A good one costs as much as another battery and I think that is where money is better spent.

Reason is - most people dont drive their boat far enough to properly charge a depleted bank of stereo batteries and no alternator is capable of giving a complete charge. Alternators are designed to provide general systems operating power not complete battery charging. This is true even if you have a huge 200A alt, it CAN NOT properly, fully charge batteries.

Deep cycle batteries are a MUST. Starting batteries are designed to give up a large amount of energy quickly but will have poor long term performance, much like a sprinter. Deep cycles are opposite, they dont like a starting draw but discharge more consistently and have more duty cycles due to thicker plates.

My general stereo rule is one 31 series battery per stereo amp, MINIMUM. If you want to be the rockstar party, double. Dont get too hung up on weight. an extra 200# is not going to cut top speed. A smaller boat like Hammer will be governed by water conditions long before weight most of the time. The batteries are no different than an extra person or 1/3 tank of fuel. If you are really trying for a top speed run, pull the batteries along with everything else that will be left on the dock.
With the price of fuel, it does not take long to burn what an extra battery would have cost. You wont be "that guy" running his boat just to keep the stereo going while creating so much exhaust noise it pisses off everyone else.

A quality, "smart" battery charger, 20amp. Plug in every night after use. Carry a standard extension cord and 30amp adapter to plug in at docks
A manual perko switch is fine. For the most part it will be left on "1" meaning the start battery will be protected from drain (assuming all stereo components are segreated to the "2" battery bank).
In general, only switch to 2 if driving for a distance and planning to play the stereo.

Personally, my stereo strategy for extended coving is to chill for the first hour or two while things are warming up and let every other one/two battery boat burn up their juice. Then when people are ready to get going, you have the power to carry the party.
(well that was my strategy till I started using a gen and power supply, but thats a whole another level )

Any good deep cycle like Interstate is fine, Optima may be more durable if you boat really rough because of their spiral plates. Kinetik and XS are premium but will out perform standard deep cycles.

US1 Fountain

iTrader: (1)

Defenders carrys them. Search Blue Seas Add A Battery.

I personally had the 500A model. Built like a brick chit house. Seen other brands, I'll stick with Blue Seas.

Should have stated the Blue Seas units are battery relays, more so than combiners. Same thing though, different way of switching. Never heard of one of these going bad from my participation on a sailing/cruising, yacht message board. Those guys live on and travel around the world on their boats. A little more dependent upon quality products to control their house battery banks than worrying about their stereos.

But I agree, A good battery and a charger will be the best option, if you can plug in at night. Otherwise, any type of battery management system will get the job done the same way. No 1 setup is going to recharge a battery out on the water any faster than another. Some require driver input each day (battery switches) and some are a no touch devise, battery relays (or combiner, depending on the brand)

pstorti

iTrader: (2)

I have the blue sea auto battery switch and also two pairs of BEP switch clusters to control my 4 batteries, both work great, keeping everything fully charged and keep my starting batteries isolated.

jonyb

Sadly, no one ever understands this. I always recommend an on-board charger for my customers that add stereo batteries.

tcelano

I'm running 4 optimas. One starting battery per engine, and two deep cycle versions in parallel. I have the blue seas relay, purchased at west marine. It simply combines the two house batteries to the port starting battery when voltage is over 13.2. If you want, there is an input you can hook up to your starting circuit that makes the relay drop out immediately when cranking. I had a 100a alternator put on the port side. I have an installed dual battery charger that I leave plugged in almost all the time.

I also put a heavy relay between the starting batteries so I can get a little extra amperage to start the motors when needed. Once the first one starts, I've got plenty of juice to start the second, then disconnect immediately to prevent the alternators running in parallel.

Plowtownmissile

I have a Kinetik for the stereo battery and regular deep cycle for the rest. At the end of the day, the battery tender goes on it.