output votage too high?

[nyquil junkie 225]

I have a 303447-0447-01 B&S vanguard on my WH loader... The battery died and so I replaced it with another, no biggie.

 

I noticed the output on the dash, it is charging at full throttle at 16.5V.  I put a meter on it to check, and its right... 16.5, in the red zone of the meter. When I put it down at a low med idle, it is about 14-15v.  But working it is at full throttle sometimes so now I wonder...

 

Is 16.5v DC charge too high?  Seems a bit high... I dunno. So I'm asking before I cook the battery.

 

Which might be what happened to the last one?

 

What is the normal full throttle voltage output for a B&S V twin?

[Achto 27,572]

24 minutes ago, nyquil junkie said:

Is 16.5v DC charge too high?

 

16.5vdc is too high. It's possible that your regulator/rectifier is faulty. 

[oldlineman 1,481]

absolutely to high will cook the battery for sure. I would as Achto has stated suspect the regulator/ rectifier. Bob

[pfrederi 17,739]

B&S regulators may not be the best i have read on here where some have put in the Kohler mount in engine shroud type....

[lynnmor 7,306]

Make sure that the regulator is properly grounded, I believe yours is grounded thru its case but I can't see it from here.

[kpinnc 12,031]

10 hours ago, nyquil junkie said:

Is 16.5v DC charge too high?  Seems a bit high... I dunno.

 

My Magnum 10 fluctuates quite a bit depending on how much a load the battery places on it. Right after cranking- especially if the tractor has sat for a while, my rectifier runs at 16.5 or higher, but settles back to around 14 volts after a few minutes.

 

If you're getting 16.5 continually, it may be high. I'd run the engine 15 mins with a known good battery and check then. 13-14 volts continuous should be nominal, and even down to 12.5 or so after 30 mins run time.

[Horse Newbie 7,069]

17 hours ago, kpinnc said:

 

My Magnum 10 fluctuates quite a bit depending on how much a load the battery places on it. Right after cranking- especially if the tractor has sat for a while, my rectifier runs at 16.5 or higher, but settles back to around 14 volts after a few minutes.

 

If you're getting 16.5 continually, it may be high. I'd run the engine 15 mins with a known good battery and check then. 13-14 volts continuous should be nominal, and even down to 12.5 or so after 30 mins run time.

I agree… 16.5 for a while… then more around 14 or so.

I have a new regulator on my 520 H , and it is stored with a Battery Tender so it stays around 14.

[nyquil junkie 225]

I ordered a new regulator for it.  Cheaper than a new battery. 

[kpinnc 12,031]

When you crank one of these old tractors, the battery voltage can drop to 10V almost immediately. That's why the rectifier gets worked so hard until the battery comes back to around 12.5 or so. Depending on the health of the battery, that can take 15 minutes, or longer if the battery is weaker.

 

I tend to think of it like an old school set of scales. Battery on one side and rectifier on the other. As the battery load decreases, the scales even out. Even a brand new battery topped off recieves about 12.8 volts continuously. 

Edited December 19, 2021 by kpinnc

[nyquil junkie 225]

Fortunately it has a clear epoxy cover to see... yup its burnt.  I just got the $14 Amazon special (made of the best Chineseium available) in the mail today so.... repairs underway.

 

eDiT:  That fixed it... now it runs at 14.6v at full throttle, 13.5 ish at low idle.  Good enough.

 

 

 

Edited December 20, 2021 by nyquil junkie

[pfrederi 17,739]

Glad it worked out for you!!

[nyquil junkie 225]

I'll have to keep an eye on that meter... that no doubt is what killed the last battery.

 

 

[lynnmor 7,306]

3 hours ago, nyquil junkie said:

I'll have to keep an eye on that meter... that no doubt is what killed the last battery.

 

 

Keep in mind that it works the opposite way as well, a "killed" battery is the same as no battery and that can toast the regulator.

[nyquil junkie 225]

Well the thing has an electric fuel pump so... if its too dead to turn the engine ovber its too dead to run the fuel pump and it wont run anyway.

 

But good point for the other one I have with a mechanical pump.