Battery Issue

[WHIPPED502]

This past summer I changed my battery set up. I added 1 more battery for a total of three. I have one Optima red top running of of the #1 position on my Perko for starting and two Optima blue tops off the #2 position on my Perko for the stereo. The problem is the red top will not start my boat. Sometimes it will slowly crank over the engine a couple times and then die. The boat cranks and starts no problem when on the #2 position.
I replaced the red top once thinking it might be a bad battery. No difference with the new one. I have double and triple checked connections at battery, starter and Perko switch. The two blue tops are in original location. The red top is on the other side of the boat. It is about a 10 to 12 foot run from the Perko to the red top. Could the cable be to small for this long of a run? I don't know what size it is but I could give Al and Eds a call to see what they usually use since they did the install. Is there a way to test if I need a larger cable? With this long of a run is this battery not strong enough to crank over the engine no matter what size cable I use? The engine has only about 7.5:1 compression but has a Whipple on it with FI. Thanks for any help anyone is able to give.
John

[phebus]

Is the battery getting charged? What position do you keep the Perko switch on, and are you switching it as you should. If you keep it on the all position, the accesories (stereo, etc.) will place more of a draw then the alternator will replace. You most likely need to hook the batteries up to a charger after use to keep your bateries up.

[Havasu Hangin']

How long is the cable, and what gauge is it?
I'd go with 2 gauge at a minimum...but that's me.

[WHIPPED502]

The battery has been fully charged and still does not start the engine. All three batteries get mantained with a trickle charger.
I don't know what gauge the cable is, but the cable run is about 10 ft.

[riverbound]

you might want to try and bypass the perko. It is rare but I have see them fail and not let enough current through.

[Havasu Hangin']

The battery has been fully charged and still does not start the engine. All three batteries get mantained with a trickle charger.
I don't know what gauge the cable is, but the cable run is about 10 ft.
10 feet is pretty long. Most boats use 4 gauge. When I swapped mine out...most of my starting problems went away.
Like RB said, start bypassing stuff and see what happens.

[OutCole'd]

Here is a great place to get cables. This is where I just got new cables for my golf cart.
http://www.weldingsupply.com/cgi-bin/einstein.pl?Next::1:UNDEF:OR:terms::PA

[WHIPPED502]

Thanks for the replys. I have always thought it might be that the cable is to small a guage for that long of a run. I could have put the battery closer but there is an actual spot on the otherside for two batteries and I wanted to spread out the weight a bit. Is there a way to test if I need a larger cable?
I will bypass the perko and see what happens.
I will also move one of the blue tops and see what happens.
John

[cruser]

Measure the voltage drop in the cable while trying to start the motor. Connect one side of the volt meter to the starter end of the cable. Connect the other end to ground. Turn the motor over while watching the volt meter. Is this enough voltage to start the motor? Do the same test when the Blue tops are in the circuit. The difference in voltage is due to the resistance of the cable. Or possibly due to the internal resistance of the Red top battery, but you said you replaced that already with no improvement.
You could also temporarily move a blue top to the red top location to see if it starts ok on the blue.

[Norseman]

Try running a good pair of jumper cables, HEAVY WIRE, between the redtop and the starter. If the battery will now start the boat, it's sometihng in between, probably the cable. Are you running positive and negative cables back to the engine?? The ground cable also needs to be a "GOOD" cable
I usually run #2 welding cables when I trunk mount batteries in the car. Still have not mounted anything in the boat. I don't need batteries if it's all in pcs. ;)