Briggs Stratton Wiring

[dennis]

Engine B&S 10.5HP Intek

Model 21R707, Type 0130-F1, Code 200121ZD

This engine has 12V electric start, with 16 amp alternator. There are two leads from the alternator to the regulator/rectifier. There is one red lead from the regulator/rectifier. Can that lead be connected directly to the battery for charging, or is some type of diode required between the regulator/rectifier and battery?

[bgsengine]

Engine B&S 10.5HP Intek

Model 21R707, Type 0130-F1, Code 200121ZD

This engine has 12V electric start, with 16 amp alternator. There are two leads from the alternator to the regulator/rectifier. There is one red lead from the regulator/rectifier. Can that lead be connected directly to the battery for charging, or is some type of diode required between the regulator/rectifier and battery?

Can be, but not recommended - You want a fuse in line between the red lead from regulator and the battery. Better yet if it goes to switched power at the key switch so regulator only provides power through switch (and fuse) when engine is running. But in a pinch, yes you can hook the regulator output to 12V+ because that's already been turned into DC voltage (the 2 leads FROM alternator TO regulator are AC Volts - each one half of the sine wave, which the regulator then turns into 12V DC volts)

[dennis]

Thanks, bgsengine. There is nothing powered by the single red lead from regulator, nothing. Just used to keep battery charged. Not sure what size wire looks like #16, but very small, so maybe a couple amp or less fuse?

[bgsengine]

if the only thing it does is recharge the battery, sure a 5 amp fuse would be just fine.

[bgsengine]

if the only thing it does is recharge the battery, sure a 5 amp fuse would be just fine.

Although you might consider 15 amps , if it is a regulator-rectifier (and you don't know the output) - They can be anywhere from 3 amps to 16 amps so you might need a 5 amp, 10 amp, 15 amp or 20 amp fuse..

[dennis]

Thanks. I always like to use the smallest rated fuse that does not blow.

[dennis]

Thanks. I always like to use the smallest rated fuse that does not blow.

Hope this isn't a dumb question, bsgengine, but is the fuse between the regulator and battery to protect the regulator? I read that the lower the battery voltage, the higher the amperage. If the battery had an internal short, I wonder if that would really jump up the amperage, and affect the regulator?

[bgsengine]

Thanks. I always like to use the smallest rated fuse that does not blow.

Hope this isn't a dumb question, bsgengine, but is the fuse between the regulator and battery to protect the regulator? I read that the lower the battery voltage, the higher the amperage. If the battery had an internal short, I wonder if that would really jump up the amperage, and affect the regulator?

NO, fuse is to protect the battery and electrical system (against potential fire) if the regulator were to short out or fail allowing battery voltage through to ground (or via the stator windings, though unlikely with a regulator) the result is equivalent to shorting battery to ground - extremely hot wires, burning wires, leading to fires and worse.

Same reason you want a fuse or circuit breaker in household wiring, or in your car - protecting against shorting out the electrical system. So, the closer to the battery or whatever connection terminal that you can place the fuse, the better (less wire to rub on metal parts and short out) - that's why you often have to dig into a wiring harness or tight tractor compartment near the switch or dashboard to find fuse holders, since they'll be closest to the "terminal point" of the circuit - which usually starts at switch , or solenoid, etc.

[dennis]

Thanks.

There is no ignition switch on this setup (only magneto kill switch). What I have is a fused wire from the positive battery terminal, going directly to a momentary starter button. I have a 10 amp inline fuse in that wire. Then, from the other side of the starter button, a wire which goes directly to the positive terminal on the solenoid. Then there is the wire running directly from the regulator to the positive terminal of the battery for charging. So, I guess I need a fuse in that wire too, because, as I said before, there is no ignition switch.

[bgsengine]

Thanks.

There is no ignition switch on this setup (only magneto kill switch). What I have is a fused wire from the positive battery terminal, going directly to a momentary starter button. I have a 10 amp inline fuse in that wire. Then, from the other side of the starter button, a wire which goes directly to the positive terminal on the solenoid. Then there is the wire running directly from the regulator to the positive terminal of the battery for charging. So, I guess I need a fuse in that wire too, because, as I said before, there is no ignition switch.

Just hook up your charge output wire to the same terminal as that fused 12V from battery to starter button, at the switch terminal. Simple.