3 amp system - overchaging update

[Lagersolut 613]

I've been at my wits end on this overcharging issue with my 310-8, tried cleaning grounds, diodes etc and nothing worked . called a local reputable tractor dealer/service center and went over it with a tech on the phone - somewhere buried in the Kohler files ( not on any parts list not even through Toro ) this tech found a Kohler Diode repair/update part/number for a 70 watt 3 amp stator .

 

Just got it in the mail today so I haven't installed it yet - I'm hoping this solves  the problem - hoping to get it in Sunday .

 

Has anyone seen this kit before ?

 

Kohler part # 25 755 31-s

 

Kit comes with instructions , 1 wire lead , shrink tube and 1 diode

 

 

[Geno 1,928]

That's the charging diode (regulator) kit, I've put them in before, it's about the only thing that goes wrong with them charging wise.  Did you say you already replaced the diode? 

Edited December 12, 2014 by Geno

[Lagersolut 613]

That's the charging diode (regulator) kit, I've put them in before, it's about the only thing that goes wrong with them charging wise.  Did you say you already replaced the diode? 

 

 

I used 3 amp Diodes from Radio Shack the first time

[Lagersolut 613]

Geno I'm curious how and where you found the info for this kit , I couldn't find anything anywhere on the net , parts lists or even here .

[Geno 1,928]

You only put in 1 right?      

 

My   dealer in Jersey has been selling them since the late 50's, he rattles part numbers off of his head.  When I need something I call him and he sends it to me. 

Edited December 12, 2014 by Geno

[Lagersolut 613]

You only put in 1 right?      

 

 

The radio shack Diodes didn't work, I was charging at over 16 volts and one Diode got me to 15.94 on the multimeter .

 

But yes 1 diode

Edited December 12, 2014 by Lagersolut

[Geno 1,928]

This one will go right where the last one did.  

[Lagersolut 613]

This one will go right where the last one did.  

 

 OK  thanks -  I'll be one happy camper if this fixes my overcharging

[Wishin4a416 2,185]

Please keep us posted.

[boovuc 1,090]

I have three Radio Shack diodes in mine and I still charge at 16 volts "IF" I am running a Walmart battery. The real good Huskey Battery and another Diehard battery I bought work and charge just fine!

[Lagersolut 613]

I have three Radio Shack diodes in mine and I still charge at 16 volts "IF" I am running a Walmart battery. The real good Huskey Battery and another Diehard battery I bought work and charge just fine!

 

 

This tractor still has the same battery in from when I bought it last year , what scares me is there's nothing , not one marking or  label on it  indicating the manufacture and on the front side is big letters melted into the plastic battery case :

 

SECOND

Edited December 14, 2014 by Lagersolut

[Lagersolut 613]

New battery, new Kohler Diode went over all grounds

 

16 volts + @ 1/2 throttle .

 

No idea anymore .

[Geno 1,928]

Are you looking a a multimeter of the charging gauge?  

[Lagersolut 613]

Are you looking a a multimeter of the charging gauge?  

 

 

Both, I have a tractor supply  ( brand new)  volt meter installed on the tractor and I'm taking measurements with my Ideal multimeter . 

 

16 -16.10  VOLTS at 3/4 throttle - I even put 2 radio shack diodes downstream of the Kohler diode afterwords and it changed nothing .

 

Checked my AC voltage at the lights and it's a good  10-11 volts

 

I'm wondering if my stator isn't bad or grounded out on the charge side. 

[bmsgaffer 2,043]

I am not very familiar with the 3 amp charging system, but I am with electronics, so I have a question.

 

The diode is basically taking the AC output from the stator and turning it into a positive half-wave to charge the battery. There is no circuit in there that would allow for the voltage to decrease as the battery charges like in the regular rectifier/regulators. The current should decrease though, as the battery output will rise to match the charging system output...

 

We may have to get SOI in here to help me if I am going astray, but it seems like 16V is just where it will stay. The voltage is less important than the current as far as charging a battery. Adding diodes should decrease your charging voltage by .3-.7v (depending on the type you use) for each one, but if you bring it down to the 14v then your battery will not charge very well, and you will have a lot of diodes soaking up the heat of the charging.

 

So all that to ask, is that just a normal way for the single diode system to operate? Is the battery showing signs of failure from overcharge? What is the resting voltage of the battery?

 

If you have an ammeter function on your multimeter (make sure it is capable of 10A) you can put it in series right after the diode to see that when the battery is reading full charge the current output should drop down to just what it takes to run the tractor (not much).

 

SOI, step in if I am way off base, but I have seen a lot of these threads and I just cant find much wrong with the 16v readout. (I do not own one to test though)

 

 

EDIT: it is nearing three in the morning and my brain is functioning at far less then capacity so I will come back and reevaluate my statements in the morning, but feel free to leave your thoughts.

 

 

We could develop a full on 3A rectifier/regulator circuit for all these people that struggle with it to make it more robust....

Edited December 15, 2014 by bmsgaffer

[Save Old Iron 1,563]

I have three Radio Shack diodes in mine and I still charge at 16 volts "IF" I am running a Walmart battery. The real good Huskey Battery and another Diehard battery I bought work and charge just fine!

 

Do not underestimate the significance of this observation

[Save Old Iron 1,563]

 There is no circuit in there that would allow for the voltage to decrease as the battery charges like in the regular rectifier/regulators. The current should decrease though, as the battery output will rise to match the charging system output...

 

 you will have a lot of diodes soaking up the heat of the charging.

 

 the current output should drop down to just what it takes to run the tractor (not much).

 

 

more pieces to the puzzle.

 

voltage rising

 

less current flowing

 

diodes not dropping their characteristic .7 volts

 

different batteries show different results in the same charging circuit

 

E = I x R

 

what happens to diode voltage drops when I (current) approaches zero?

[Lagersolut 613]

It was mentioned if I had symptoms of over charging, in my opinion yes, corrosion build up on the positive terminal, I've actually had 4 different batteries -original , 2 from other tractors and now this one, new from Lowe's ( yesterday ) maintenance free and the results never change for me on the 16 volt reading . .

[gwest_ca-(File Mod) 10,488]

Just for fun check all the diodes again. Use the ohmmeter on the leads and then reverse the leads. Are they all still blocking current flow in one direction?

 

Garry 

[bobert94 38]

Where is the diode located ive always wondered how this system works without a regulator.

[Lagersolut 613]

Where is the diode located ive always wondered how this system works without a regulator.

 

About 6 inches from the stator on the battery charge lead - you can ( least I could ) get to it without pulling the flywheel, pulling the stator makes it 10x easier to  to do your soldering on a flat surface but maneuvering the  leads back behind the bearing plate is a real pain .

Edited December 15, 2014 by Lagersolut

[Lagersolut 613]

I have an idea, electrical isn't my strong point so no idea if this is a good or bad idea -

 

Run the charge lead circuit through a toggle to turn on/off  to control the charge ?????

[Geno 1,928]

About 6 inches from the stator on the battery charge lead - you can ( least I could ) get to it without pulling the flywheel, pulling the stator makes it 10x easier to  to do your soldering on a flat surface but maneuvering the  leads back behind the bearing plate is a real pain .

 

When I do these I attach a wire under the shroud and relocate the diode outside of the shroud in case it has to be replaced again later. 

[gwest_ca-(File Mod) 10,488]

Just for fun check all the diodes again. Use the ohmmeter on the leads and then reverse the leads. Are they all still blocking current flow in one direction?

 

Garry 

I should expand on this.

 

Diodes should pass current in one direction only.

An open diode won't pass current in either direction.

A shorted diode will pass current in both directions.

 

Not long ago a member had a similar overcharge condition and found the diode was shorted. I don't know if there is a condition that would repeatedly short diodes but if there is the failed diode may be the result of another problem. That was my thought in rechecking the replaced diode's condition.

 

Garry

[Lagersolut 613]

Checked the Diodes Gary, they are working properly so it's not frying Diodes .