Opinions on idling

Mr_Shamrock

Petty Officer 2nd Class
Joined
Oct 8, 2009
Messages
127
We were out yesterday and had a great time. I have a decent stereo system on my boat and usually end up being the DJ for the beach parties. Yesterday we stayed longer than usual and the battery got low (I could tell the music wasn't sounding as good) so I started the boat up and let it idle for about 30 minutes. Does anyone see a problem with this? It is a Yamaha F150 4 stroke. The reason I ask is a guy told me yesterday that it was bad for the motor to not be in motion for extended periods. Any thoughts?
 

mimmik02420

Cadet
Joined
Aug 28, 2010
Messages
13
Re: Opinions on idling

Maybe on the 2-strokes but not a 4. It's not really "bad" on a 2 stroke either it just fouls plugs, sputters on acceleration, and it'll eventually require service. I idle quite a bit without troubles with my four stroke when trolling live bait. Charging a battery you may want to slightly increase the rpms though as the idle amperage output for the alternator isn't great while idling.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Opinions on idling

2 or 4 stroke if running correctly will idle for hours and not sputter.
however your F150 has a built in battery isolator to charge a house battery seperatly from the starting battery,why not use it?
 

Mr_Shamrock

Petty Officer 2nd Class
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Oct 8, 2009
Messages
127
Re: Opinions on idling

OK I feel dumb, what is a battery isolator and how do I use it?????

Right now I have dual batteries on a Perko switch.
 

Mr_Shamrock

Petty Officer 2nd Class
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Oct 8, 2009
Messages
127
Re: Opinions on idling

Also what are your thoughts on whether or not I should -

A. Upgrade my 2 current 24 series batteries to 27 or larger. How much difference will the upgrade make? My 24's are on their 3rd and final season so it will be time to replace/possibly upgrade soon anyway.
or​
B. Install a third battery using 2 for the electronics and one strictly for starting.
or​
C. All of the above.

If I add a 3rd battery how will my dual bank charger work. I currently have a Guest dual battery charger that is hard wired with an external plug that has a rubber cap over it. So now I simply pop the rubber cap and plug in an extension cord. Will it need to be upgraded to a 3 bank charger?
 

Mr_Shamrock

Petty Officer 2nd Class
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Oct 8, 2009
Messages
127
Re: Opinions on idling

OK I did a little research and it appears an isolator will charge an additional "house" battery separate from the cranking battery. My question is this - what is the difference between using the Perko switch and hooking up the isolator lead. Right now here is my procedure - put the switch on "2" this is the starting battery, Start the motor, Switch to "All", Ride out to wherever we are going to hang out for the day, upon arrival switch to "1" this is where I have the amp wired to, when we leave I put the switch on "2", start the motor, put the switch on "1" to recharge the battery that the stereo runs off of, at this point we either head back in or find another spot to hang out and the motor will charge the stereo battery up a bit while we are cruising. Am I doing something wrong?
How would this vary from using the isolator lead? If I understand the switch properly I am isolating the batteries myself by switching from "1" and "2" right?
 

rodbolt

Supreme Mariner
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Sep 1, 2003
Messages
20,066
Re: Opinions on idling

maybe, maybe not. depends on the minimum wage rigger or backyardigan that rigged it.
probly didnt even know all F150 motors had a battery isolator built into the engine harness.
you will need to buy or make the lead kit with a 50 amp fuse.
for the sake of argument we are gonna make 1 your starting and 2 your house.
remove all wiring from the common and battery 1 positive terminals except the wire from the battery terminal to the switch and the engine positive, clean and tighten and spray with with a corrosion block.
move all those wires to the battery 2 terminal on the switch.
now you should have the positive lead from batt 2 and all house functions on battery switch 2 terminal. now bring your isolator to the battery two switch terminal.
now battery two is isolated from battery 1.
all battery switch terminal 1 should have is the positive cable lead from battery 1.
all the Common terminal should have is the engine positive.
if you wish you can leave the automatic bilge power feed on the battery 1 switch terminal so its not affected by dead house battery and supplies the pump even when the switch is off.
now while zipping down the bay on batt position 1 we are charging 1 and 2.
pull up toss the anchor crank some tunes and open a cool refreshing beverage and we are draining batt 2 and never moved the batt switch.
run home and we are charging both again and still have not moved the switch.
if batt 1 fails shift switch to all and it will crank off batt 1 and 2.
switch to batt 2 and it cranks off of batt two.
as far as amps, its like horse power, if it fits you simply cant have enough.
if you wish to add a third battery for a 2 bank house simply parralell the + and - of both house batterys.
ALL - batt terminals must be connected at the negative terminals with a wire of a gauge not smaller than the largest ground wire in the hull and engine.
yes virginia, its as simple as that.
 

Mr_Shamrock

Petty Officer 2nd Class
Joined
Oct 8, 2009
Messages
127
Re: Opinions on idling

You are the man - thanks! One more question, if I were to add a 3rd battery how does the alternator handle charging all 3? I am sure there comes a point where the alternator can't handle the battery load right? How do I know where that cut-off is? Sorry for all the questions - Thanks for all the answers!
 

Triton II

Commander
Joined
Nov 23, 2004
Messages
2,479
Re: Opinions on idling

The alternator via the rest of the charging system puts out a specific amount of amps, just the same way an engine puts out a specific amount of horsepower. If the draw on all three batteries exceeds the charging systems output, the batteries will gradually drain. It won't (it says here!) hurt the alternator. In normal use, if you've drained the two deep cycle "house" batteries, it'll slowly recharge them with the engine running - providing you turn off the equipment that's creating the draw. The bigger the batteries, the longer it'll take to charge them, but, as the F150 has plenty of power output from its charging system, personally I wouldn't worry about it.

TII
 
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