I recently updated the stereo in my scarrab. I installed 2 13W6V2 JL Audio subs ( and capaciter) under the back seat along with 4 6.5 MB Quartz. In the cuddy I put 4 6.5 Eclipes and a 10" AudioBan 100watt self powered bass tube. Over all its crankin about 1800 watts. I added 2 more optima batteries (3 for stereo,1for motors) I am getting it ready for spring and dont want to run out of juice while the hotties are dancin on the boat. Does any one know much about solar chargers? Would it help to have one? two?

YOU WOULD NEED A SOLAR CHARGER THE SIZE OF TEXAS TO KEEP UP WITH THAT MUCH POWER JUST PLAY THE RADIO FOR A WHILE THEN CRANK THE ENGINES FOR A WHILE. MAKE SURE YOU KEEP A CHARGED JUMP BOX ON BOARD. ALSO YOU COULD GETA SMALL 1K GEN AND USE IT TO CHARGE THE BATTS WHILE YOU ARE JAMMIN WITH THE HOTTIES

Your alternator will have a hard time charging 3 flat batteries unless you run it for several hours. A deep charge will be needed to fully charge the after near full discharge. You should be fine with intermittent charging through the day when they get low. Some alternators do not put out very much at idle. The Mando alternator has an internal regulator that you can access and tweak to raise the voltage.

You will need a good "smart charger" to bring them fully up when you get back to the driveway or dock.
http://www.vectormfg.com/battery-chargers.php

For overnighting I have considered a small Honda generator to top off the batteries. Just set it on the swim platform with some suction cup mounts and let it spin, they are pretty quite. An alternator upgrade may be in order.

Thanks guys I thought I might need to buy a dingy and put a big generator in it. I do think the alternaters are going to need to be updated also. Thanks again

you should have a second battery for the engines, safer. for the stereo batts. you should install a battery isolator so you dont draw from your boats main batts when parked and pumping tunes. as well it will keep your engines and boats electrical systems from spiking when the bass hits, i didnt read any mention of a capacitor to prevent this. if it is a newer engine , merc app. , then the alt is probably 90 or 120 amps and sufficient. remember good grounds and proper wire size for the long runs if any.

p.s the batteries for the stereo should be deep cycle

Thanks I did install a 2 fared capaciter for the subs. the boat has been set up with 2 differant batt switchs (installed before I bought it) I did buy 4 optima " Blue Top gel" wich they told me will charge 100% verses others they said wouldnt. Thanks for the info