View Full Version : Batteries and charging
03-11-2012, 08:32 PM
I have an X-80 with the standard dual battery set up with isolator and Perko Switches. I'm upgrading the stereo system and want to install the right batteries and dual bank charger to run a standalone system so I dont kill my alternators.
I live in Hawaii...so the cold isnt an issue for battery selection.
Stereo set up: (1) Syn 4: 75Amp, (2) Class D amps: 60 Amps each....total 195Amps.
I have a 250A breaker with 1O wiring powering the breaker and to the junction. I'm running 4Gauge to each amp.
What are the best batteries to run, and best way to wire (Parallel, Series?). and How long would I expect to run the stereo moderately before a recharge. We go out and camp on the beach for 2-3 days at a time....so I can bring my honda gen to recharge when necessary.
Any rec's for dual bank charger?
03-11-2012, 08:45 PM
I run some group 27 batteries from costco that are 115ah each. I paid $75 each for them. I'm running a syn4, kicker zx350.4, and kicker 1000.1 and can play all day most of the time. I killed the batteries twice last year playing it loud for about 8 hours. If you have the space, I would go with 3 of those batteries.
You want to wire the batteries in parallel. Wiring them in series would make it 24v for 2 batteries of 36v for 3 batteries.
I have a guest 2611a that is 5amps per channel. I don't have any complaints about it, but if I had to do it over again, I would probably go with a promariner prosport20+. Several of my friends have them and are really happy with them.
03-11-2012, 09:33 PM
The only time you will series a battery is if you use two 6 volt batteries run together to achieve 12 volts. Never series a 12 volt battery in a 12V boat application unless it is for a trolling motor.
Weight is the great equalizer for specifications that may or may not be accurate. Its highly unlikely that you will get more than 80 amp/hours from a 50 lb Group 24, 95 amp/hours from a 60 lb Group 27 or 110 amp/hours from a 70 lb Group 31. A heavier deep cycle battery will certainly have more amp/hours and a lighter battery will have less.
For consumer grade deep cycle battery longevity you would ideally like to keep your depletions limited to 50 percent or 12 volts.
For worse case, at 50 percent depletion, estimate around 50 amp/hours of battery capacity for every 1000 watts of Class AB amplifiers driven at full power for one hour. Class G/H is more efficient yielding more time. Class D is 60 percent more efficient yielding more time. Your system efficiency (including sub enclosure, speaker efficiency, amplifier efficiency), accuracy of power specs, age and condition of batteries, starting charge of batteries, regulated or unregulated amplifiers, how loud you play it, quality of downloads, system tuning, equalization, music type, etc. can have a profound impact on the play time at rest. Music is transient in nature so it's going to be a very different calculation than DC bulbs for example. Music can represent a very wide dynamic range at a moderate volume to a very compressed dynamic range as you approach full volume so this can also be a major multiplier of play time. Compression consumes much more power.
For an AC shore battery charger you want a smart multi-stage, minimum 2-bank (depending on the amperage capacity required you may be forced to get a 3-bank charger even though you will only use two) with a total amperage capacity between 10 and 13 percent of the collective amp/hours of your batteries. This is required for proper desulphation when you are seriously deep cycling batteries. Tenders/minders/trickle chargers are for those applications when the vehicle is placed into storage with the batteries fully charged...but not good for the above usage.