6 Volt Generator Boat Question
 

I have two 10 hp 4 cylinder Ford flat Heads in my boat, both are 6v both have 6 volt generators, both very old and a bit slow to turn over, (all new hd cables ect ect) they are completely independent from one another, I would to like to link the batteries, to up the amps to help spin the engines over, when I tested it it worked well, but can both Generators be charging, what would be the one battery when they are linked and the engines both running??

Re: 6 Volt Generator Boat Question
 

OK Shaun... here goes...

Typically on a twin engine system the port side is for starting and the stbd is for "house", or vice versa. Each generator charges each bank. Stay with me here...
My Roamer (12 volt system) HAD 2 - 6 volt batteries in series which made 12 volts with a huge capacity. I now have it set up with 2 - 12volt batts in parallel. You would run yours in PARALLEL for 6 volts with the double capacity. Set up like this, the gen will equalize the two batteries. If one is bad the other will work, but kinda overtax that generator. With batteries in SERIES, a bad cell will kill the bank (open circuit) and the generator will probably smoke from overload.
Now for the good part... The P & S are tied together with a parallelling solenoid with a switch on the dash. If the start bank is dead, parallel the other house bank to start. Just a redundant start system.
If you need me to, I can draw you up a pretty simple schematic... PM me if you it... ws

Re: 6 Volt Generator Boat Question
 

Shaun, you mention new HD cables. What gauge are the cables? In a 6 volt system it is very important to clean every electrical connection and for the starters to be in good shape. You mention slow to turn over. Is this compared to your newer automobile? If the engines are in good shape and in tune, they should start without much trouble but they won't spin like a new car. Let us know more details.

Re: 6 Volt Generator Boat Question
 

Now I may be out of line here because I haven't worked with electronic stuffs for many years but I have something in the back of my mind that's bothering me about your theory. And I might be completely wrong with this but I think its something like this: You actually have to be careful in regards to the resistance and amps coming across a parallel circuit. They can very seriously and adversely affect the final voltage and that's one of the reasons you have to be careful of your cable sizes.



You don't need to consider all of a parallel circuit's branches to determine its voltage. Unlike a series circuit, a parallel circuit carries the same voltage across its entire length. You rarely need to calculate its voltage at all; rather, you simply measure the voltage across any two points with a voltmeter. Alternatively, multiply the current and resistance across any branch. But if you wish to consider all its resistors, calculate total voltage after calculating the circuit's total current and total resistance.




Instructions

1. • 1 Add together the current across each resistor. For instance, if three branches carry 1 amp, 2.5 amps and 4 amps respectively:
     1 + 2.5 + 4
     = 7.5 amps
     
     
   • 2 Find the inverse of the resistance across each resistor. If the branches have resistances of 2 ohms, 0.8 ohms and 0.5 ohms:
     1 / 2 = 0.5
     1 / 0.8 = 1.25
     1 / 0.5 = 2
     
     
   • 3
     
   • Add together the three values from the last step:
     0.5 + 1.25 + 2
     = 3.75
     
     
   • 4 Find the inverse of your answer.
     1 / 3.75
     = 0.267
     
     
   • 5 Multiply your answer to the answer from step 1.
     0.267 * 7.5
     = 2 volts
     
     

Just my $.38 worth. And remember:

V = I x R (Voltage = Current multiplied by Resistance)
R = V / I (Resistance = Voltage divided by Current)
I = V / R (Current = Voltage Divided by Resistance)


And it also helps to have a digital multimeter.


Or as I said up front in some way I might be full of colon matter. In which case defer to these guys.