1641 with Briggs Vanguard AC Volts
 

This has a 16 HP Vanguard and I've read about the charging issues with these. I've got a situation where the battery is showing 13.5 - 14 volts with no load and nearly full throttle. When I engage either the headlights or the PTO the voltage starts to drop by a tenth or so every 10 to 15 seconds.

I checked the AC volts coming off the stator and at start up and nearly full throttle I'm reading 27 to 29 volts. When I turn on the lights or the mower deck those volts drop to 24 to 25 and do not recover until the load is removed. Since this happens with either the lights or the PTO it doesn't appear that I'm losing any RPMs with the PTO engagement.

I'm no electrician, and here's my question, why does adding an electrical load (lights or PTO) cause the stator output voltage to drop? I thought the stator output would stay constant and that the regulator would vary the DC output based upon the load. Do I have a stator or flywheel magnet issue or a lack of understanding regarding how this works?

Thanks in advance for any input regarding this.

Bruce

First let me say, My 1641 did the same thing or even worse before I replaced the stator. With that said. In a DC system "even with AC output converted to DC" You will see fluctuation when running different circuits IE lights, PTO. The stator output is only 12-15 amps max. So when you run say the PTO drawing 4-5 amps or a 3rd of the available you will certainly see some drop. Keep in mind that the wire thats actually putting the charge to the battery from the stator and VR is relatively small. Its not much more than a battery maintainer really. Now with the older style cubs that have a generator with heavier duty wiring I see less fluctuation. You should check all of your connections.. Bright and tight as Roland says. This may help some with the fluctuation.


PS. whats the lowest your voltage drops to?

Like Coop said.

To give another analogy. Even though there is pressure on the water system in your home, open the Kitchen Faucet (load) will slightly lower the system pressure. Close the faucet (no load) the system pressure goes back to normal.

Thanks for the quick replies.

Just ran it about 10 minutes with the PTO on and at the battery it settled in at about 12.5 volts.

Be Happy Grasshopper :beerchug:

Lol. Great response. Yeah the newer stators just dont put out what you would expect. Any of my newer stuff I run for a few minutes after turning off pto just to top off the battery.

Install LED lights and be happier! :-)



( Mr Ohm reduces voltage in proportion to the amount of current flowing through the wiring... more current flowing, more voltage drop)

Just throwing this out there as I'm not familiar with your engine.
I have heard that kohler voltage regulators are long lived and seem to do a better job at keeping voltage constant.
But of course if you don't have enough input from the stator, you will not gain output.
Do check that your battery is good.:bigthink: