Installing dual batteries switch on twin OB F115 Yamahas

rodbolt

Supreme Mariner
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Sep 1, 2003
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20,066
Re: Installing dual batteries switch on twin OB F115 Yamahas

no worries :)
if space and weight permited outboard systems would most likly share more common parts but the space,weight and operating conditions are vastly different.
 

Ray Neudecker

Lieutenant Commander
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May 25, 2004
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Re: Installing dual batteries switch on twin OB F115 Yamahas

Makes a lot of sense rodbolt. Thanks for clearing that up.
 

rodbolt

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Re: Installing dual batteries switch on twin OB F115 Yamahas

Ray
the biggest issue we have with the EFI 4 strokes,and even HPDI, motors is they need a stable 12v to correctly operate the injectors and fuel rail pumps. they also use a TCI ignition system that is rather touchy.
its basically the old amplifier system triggered by pulser coils. but its a 12volt ign system.
but the F250 uses a coil in the plug cap setup and a 5volt trigger to switch the 12v coil primary current and then feeds the secondary output through a Zener diode that steps the voltage up to a minimum of 34Kv.
that set up will arc an 11/16ths gap like it was nothing, thats as far as we could adjust the spark tester :):).
on the inline 4 4 strokes they use a siamesed coil,still 12 volt but it fires 1+4 and 2+3 simultaneously.
any defect or voltage fluctuations can not only affect injector opening it can also affect ign due to low coil primary voltage.
the F250 is wild to work on though.
 

Striper Blues

Petty Officer 2nd Class
Joined
Jul 30, 2003
Messages
135
Re: Installing dual batteries switch on twin OB F115 Yamahas

Rodbolt, here is where my amateur status will be revealed,ahem. Even though I did spend 4 years in the Air Force working electical instrumentation systems, it was 30 years ago and we only swapped out black boxes (Can you say dual platform gyros?). So I'm a weekend warrior when it comes to outboard motor wring. I am confident in my ability to wire it correctly with regard to using only the right gauge wires and proper connectors and such. Its the schematic I'm struggling with.

When you say use 2, 3 positions switches do you mean as in bat1, bat2, both and an off position? I know that does seem to be a four position switch. If so,do I literally set both switches to the same position for that effect, ie. bat, bat2, or both batteries? If not can you tell me what i need and or recommend a particular switch model?

I did print out the diagrams from the 2006 rigging guide and one does show a 2 engine 3 battery install which is essentially what you've describe less the third parallel leg. But it seems they are referring to these switches simply as shut off switches.

I do have to say I love these motors. They are quiet, efficient and dependable. Which is why I will not be attempting to winterize them myself. They'll go to the shop for that.

Again you time and advise is greatly appreciated.
 

rodbolt

Supreme Mariner
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Sep 1, 2003
Messages
20,066
Re: Installing dual batteries switch on twin OB F115 Yamahas

first off dont be afraid to winterize them, its simple.
yes the off,batt1,batt2 and both are refered to as a 3 position switch as the off is considered secured and not a position.
excactly what are you attempting and why?
yes not only can I say dual platform stabilizing gyro I can say search/track processor, search processor,track processor and the difference between fire control radar and search. the CIWS had both.
one transmitter with 2 antenna's.
I spent 6 years as a CIWS tech in the USN.
I can also say M21A1 vulcan with 20mm DU subpenatrator rounds :).
can ya say 1500rds a min is bad arse :).
 

Striper Blues

Petty Officer 2nd Class
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Jul 30, 2003
Messages
135
Re: Installing dual batteries switch on twin OB F115 Yamahas

Rodbolt,
My intent is to provide a switching capability that will allow me to select both or either battery for starting purposes, if I accidentally drain one battery. This happened recently when the woman doing my canvas drop curtains hit the courtesy light switch (they aren't very visible during the day as they're recessed). It was on for a day and when I went to start the port motor the battery couldn't turn it over. I just got this boat this year and it didn't come with battery switches. I want to remedy that.

Having said all that, I have gone over the wiring diagrams and your instructions and I understand how to install the switches. What I'm still fuzzy on is how they will interact with each other as I've only had single engine/dual battery boats before. So for example once installed if I set both switches to bat1, I'm assuming they will in fact both draw from and charge battery 1, and so on. Do I understand that correctly?

Thanks again.
Striper
 

rodbolt

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Sep 1, 2003
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20,066
Re: Installing dual batteries switch on twin OB F115 Yamahas

ok
we will call battery 1 the port side and batt two the stbd side.
first mount the batteries in a holder that is in accordance with USCG regulations.
now locate a nice dry accesible place for the switches.
now run a wire of at least 4 GA from the positive batt terminal to the #1 terminal position of the port side switch,run another lead from the #2 terminal to the #2 terminal of the stbd side switch.
now run a lead from the stbd side battery positive to the #2 terminal on the stbd switch, now run a lead from the #1 terminal on the stbd side switch to the #1 terminal of the port side switch.
run all hull wiring taps from the common terminal on the stbd side battery switch with the exception of the auto bilge pump lead. Run the auto bilge lead to the #1 terminal of either battery switch.
that way even if a hull switch is left on and batt 2 dies your auto bilge still works.
for normal running select position 1 on the port and 2 on the stbd, for emergency you can select both or both on 1 or 2.
if all you want is battery parelelling capeabilities you can simply add an on/off switch and run the cable from poitive to positive battery terminals but that wont allow you to secure the battery power.
make sure all negative battery terminals are bonded together with a wire not smaller than the largest negative cable.
 

Striper Blues

Petty Officer 2nd Class
Joined
Jul 30, 2003
Messages
135
Re: Installing dual batteries switch on twin OB F115 Yamahas

Rodbolt,
Thanks again for the help. I appreciate your recommendation and will wire as suggested using two switches. I'll also run accessory wires to com terminals, separating bilge from all others...good idea.

Originally I thought about adding a third accessories battery, but I don't think I need it as I typically am doing day fishing trips. Maybe if I start camping more it will be worth it.

Thanks to all for your inputs, you guys have gotten me unstuck again!

Striper
 
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