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Discussion Starter · #1 ·
So... the regulator/rectifier turns the 3-phase AC current from the stator into DC current in order to charge the battery.

Is this the only function? What runs the on-board electronics?

The stator?
 

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It has two functions: it regulates the voltage down to ~14v, and it rectifies it to DC.

The on-board electronics all run on DC.
 

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The stator provides the power to run the loads on the bike. At initial startup, it's the battery that supplies the power to start the bike. After the bike is running, the source of the power to continue running and operating all the devices including the ignition components comes from the stator via the battery. The battery is just a storage device. There are mc and atvs and other small engine devices that do not use a battery, just an alternator or magneto to produce the power and a regulator. If DC is needed, then a rectifier as well. These motors have alternators that produce max output at low rpms vs the stator/alternator in larger engines that only do this at 5Krpm.

A simple pull start lawnmower does not have a battery. It's power generating source only needs to provide power to the coil to spark the plug.

The battery is the storage device, the R/R is the regulator and rectifier for the power generated by the stator. You can start your bike without the R/R connected. The engine will continue to run until the battery discharges to a point where not enough voltage is being provided. The gauges will also start to function poorly because of the loss of a regulated constant voltage source. There are race bikes that run on total loss electrics. The stator/alternator and R/R are removed and the bike is powered directly by the battery only. Obviously, the battery will only last as long as needed for the race. These bikes are only running the ignition with the battery. No electric start either or computers. Modern race bikes with all that computing and data logging power and computer controlled devices need a constant source of power.
 

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Discussion Starter · #4 ·
Ok thanks for clearing that up.

I had several 4 wheelers when I was younger. I remember them not needing the battery to run. That makes sense now since all that was being run was the ignition and headlights.

So what you are saying is that on modern bikes, like our sv's, if the bike was started and you cut battery out of the circuit . the bike would stop.

...i.e. the stator is not directly responsible for ignition...the AC current it generates gets rectified then goes to charge the battery, which, in turn will provide the ignition spark

correct?
 

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......i.e. the stator is not directly responsible for ignition...the AC current it generates gets rectified then goes to charge the battery, which, in turn will provide the ignition spark....
Once the engine is running, the battery contributes nothing to that condition - the output voltage of the Generator system (stator & R/R) is greater than that of the battery - so current is flowing INTO the battery, not out of it
i.e. the generating system is simultaneously charging the battery while also providing the current to run all the other systems (ignition, lighting, ancillaries etc) - however - if the generating system is broken or disconnected, then the battery current would be flowing OUT of the battery to provide the power to those same functions.

See this below for graphical explanation:
(the load is everything that draws current - ignition, lights, ancillaries etc)



I haven't shown the stator, but that would be what is supplying current to the R/R which in turn provides the generator output current
At ignition on, there is of course zero generator current so all the current is coming from the battery.
 

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Discussion Starter · #7 ·
ok...so the ignition spark does NOT in any way come from the battery?

its all from the generator system assuming the generator system is good?

So you could theoretically, according to the diagram, cut the battery out if the engine is running and the bike still run of the generator system?
 
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