Golf cart batteries not lasting as long as i thought
 

I know the battery topic has been coverd, but I haven't found a simple answer yet. I have 4 golf cart batteries (6v / 225ah each) in my malibu. I'm running all kicker amps kx1200.1, kx 800.4, and a sx 900.4... with the music up 3/4 volume I get about 3 hours of play time while parked. Is that right for 500ah? when you know the batteries are fully charged? I usually charged the bank until I get 12.6v and wait a couple hours before checking the voltage again.

What factor determines when you shut off the system? Do you drain it till it dies or to a certain voltage where the batteries are only depleted a certain percentage? With lets say 2900w at 14v, which roughly would be 2300 at 12.6v you are running it at, then calculating for amplifier efficiency (roughly about 65% sometimes lower). The amp draw could definately take it down in 3 hours depending on how far your draining them. As long as you keep them charged and maintaned you should be able to get the most out of them as possible.

have you checked the amperage draw of the system while playing and under a load ?From that point you can do some fairly basic math to determine a rough idea of what to expect. What 6 volts are you using? Big difference in some of the manufactures out there .

I usually run it until the tower shuts down. The sx amp has a voltmeter built in and i think it was at 11.5 when the tower cut out. How do i check the draw at 3/4 volume and are the batteries fully charged at 12.6v? Im running the basic "sams club special" energizer gc2 batteries.

Another couple of contributing factors are a) how far down you are discharging your batteries? You are not running industrial level batteries so they will begin permanent degradation when discharged below 50 percent charge. Cycle them too deeply enough times and you will notice a sharp decline in battery performance, b) If you have 450 amp/hours plus a typical 50 amp/hour starting battery you should have a 50 amp 3-stage AC battery charger. If you don't then your batteries may be dying a slow but certain death from sulfation, c) the most efficient speakers and amplifiers will take you only so far. Bad system design, bad subwoofer enclosures and locations, bad tuning, wrong crossover frequencies and misuse of equalization can cut your system efficiency down to a fraction of its potential.

David
Earmark Marine

What do you mean u are charging to 12.6? Is this with the alternator or onboard charger. What type of charger. Check the batteries the next day after being on the charger.

If they are flooded lead acid batteries check to make sure the fluid level is right. If not, then add distilled water.