Dual charging system overcharging

[Jim27]

Have a Briggs engine on a riding mower which seems to destroy a battery every year or two. The last one died within the 6 month warranty. In looking into the charging system my older rider had a regulator and this one only has a diode to convert the output to DC. Really poor design IMHO as an electrical engineer. The voltage after running for a while is around 16V. I considered getting the alternator stator (winding assembly) and regulator for a more conventional regulated system - either buying the parts or a blown engine for the parts. But now I see some about a regulator that looks to just plug in. Would be nice to have the higher output of the other systems but regulation is really all I need and would be a lot less work to install the regulator, especially no connector modifications are needed. But I haven't found much on it. The Briggs repower guide talks about the different charging setups but no mention of that regulator.

It's on a 2018 Husqvarna riding mower.
Engine numbers:
Model 44R677
Type 0004G1
Code 180821YG

Found this thread but for some reason I don't have access to the google drive links - maybe out of date?
https://www.lawnmowerforum.com/threads/too-high-battery-charging-voltage.65980/

 

[Jim27]

I looked at the engine and expected to find a mounting spot like on my older one with regulator but there is no hole to mount it. Looks like I would need to make up a bracket but there don't seem to be many bolts in the area to even fasten a bracket.

 

[bertsmobile1]

Yes the system is crud rude & unsofisticated
B & S usually mount their rectifiers onto the dip stick tube
The single AC wire stators are a pain because they use the engine ground to completer the AC circuit so getting a clean feed is a touch harder than the latter model stators .

 

[Jim27]

I was thinking of replacing the stator but if I can just add a regulator that would save the work of pulling the flywheel. Stators and regulators seem to be fairly readily available and the cost for the Briggs regulator for this one at about $50 is close to the cost of a stator and higher power regulator although those may be Asian imports. Here's a pic of the dipstick area - no regulator mount area at least that is obvious.

 

[jak3676]

I have no help, but I'm also eating a battery every year or two in my similar B&S 44R677-0019G1 in my Husqvarna built Craftsman. Will monitor this thread to see if you figure something out.

 

[bertsmobile1]

Jak
Pull the plug and set your multimeter to Ω or diode test
Test between the red wire & Ground
If the diode is good then you should get a closed circuit with the probes connected one way and an open circuit with them reversed
IF open or closed both ways the diode has failed
The diodes are about 50¢ replacing them is a PIA as they are connected directly to the plug pin
I cut them off completely & solder a piece of wire to the pin , then solder the wire to the new diode then the diode back to the original wire
The down side is the diode is not capped , so it passes all + voltage spikes down the wire to the battery
Thi tends to boil off the electrolyte unless you use an EXPENSIVE PVR & AGM fully sealed battery , which no one does
This system will eat flooded cell batterys for desert

Jim
Does your mower have lights ?
Do they go brighter when the engine speed increases ?
Usually this system is used for AC lighting so it can be a problem
However a simple $ 10 electrical store rectifier will work fine
One AC termina to the red wire & the other to ground
One DC terminal to battery + and the other to ground
Usually the + terminal will be marked as +
Bolt it to the inside of the blower housing near the carb so it gets some cooling air & is away from the heat
The genuine B & S item goes onto a different dip stick tube which will be a direct replacement for yours provided you stay with the same series of engines so one for a 44???? engine
When you fit them they use a self tapper for the single wire connection and the you must provide a ground strap to the body
Internally they have the double ground .
So you just cut the red wire & hook it to the yellow then run red from the rectifier back to the plug.
Leave the black wire alone

 

[StarTech]

First this setup would use the 790292 voltage regulator which need its case grounded. It setup as a plug n play install.

Another old trick is to use multiple diodes in series as each Silicon diode drops 0.7 volts

Those TE Connectivity pins and sockets are as follows,

 

[Jim27]

Yep. That looks like the regulator I need. Meant to post the number.

On testing the diode - if the ground of the stator is bad the test may show open. Diode failure mode is to short. If there is enough current after it shorts it may open.

Yes, mine is the dual system with one winding for AC to the lights and one that is rectified for the battery.

So there is a oil tube that has a bracket? Will have to check that. Gives me an idea to use a clamp around the existing oil tube and then just run a ground wire to some other place. Not sure what they are called but the clamp goes around a tube and has a bolt on only one side that pulls the clamp tighter.

Multiple diodes will lower the voltage but also lower the charging. Maybe an improvement...

 

[StarTech]

Here is actual test procedure by Briggs for the Dual circuit setup without the regulator.

 

[tcpuccio1]

once you get the voltage regulated down to an acceptable range you may want to invest in better battery the cheap ones you get a walmart are junk! think about a "Gel" battery that would be used in a jet ski. they are designed to be bounced around and will last longer then a wet acid battery!