Overcharging here too

[Wishin4a416 2,190]

I picked up a worker 310-8 about 6 weeks ago and finally got it running after clearing up some wiring issues.

I think I have the same problem as hm12460 did.

It starts out charging at 14 volts on the dash gauge[13.4 on the fluke meter] and slowly climbs to 16 or better on the dash gauge and 15.8 on the fluke meter.

I have a radio shack nearby to get some. But I dont know where the original Diode is.

Is it under the flywheel? Behind the dash is some kind of fat componet in the wiring to the volt meter but I dont know what that is.

Anyway Im not that good at wiring but I think I can get a couple diodes inline but just dont know the location or which wire.

It is an 87 Magnum # 21-10K804 and I have a diagram someone posted for me.

Any help appreciated.

Thanks

Jack

[gwest_ca-(File Mod) 10,920]

Addresses the problem but the part is no longer available from Toro and have no idea what it consisted of

 

 

The original diode was supplied by Kohler so it is in the wire harness that comes out from behind the flywheel cover. This harness is not very long where it plugs into the tractor harness. The diode will be covered with tape near that connector. 

 

Garry

[Wishin4a416 2,190]

Thank You Garry!

[wheeledhorseman 574]

Unregulated charging systems are a PIA! The fact that WH specified this for a 300 series is hard to understand but I guess it helped keep the price down to a target for the low end model. Stranger still was the decision to include a voltmeter but then these were I think a standard feature of the series.

 

These charging systems will inevitably lead to over charging if the tractor is used for more than half an hour or so but I think the symptoms, i.e. higher than normal voltage on the meter, tend to become more noticeable as a battery ages and is less able to cope with this. The fact that there was an 'optional' 'aftermarket' regulator covered in a WH bulletin indicates that this was a known issue.

 

I strongly suspect that the aftermarket regulator Garry has drawn attention to would have consisted of a 14 volt power zener diode mounted on a finned heatsink and, unlike the rectifier diode, I doubt that it would have been taped into the loom anywhere as its purpose was to draw off the excess output from the alternator and turn it into heat. Early motorcycle charging systems used this idea. Unfortunately you won't find suitable power zeners at a Radio Shack as they are not readily available anywhere that I know of.

 

If adding one or two additional rectifier diodes in series with the original diode doesn't overcome the issue for you then you could try adding an additional load for the charging system to run which would be a simple version of the zener diode method. You could for example connect a 5 watt auto bulb via a fuse  to operate when the ignition is turned on. If this doesn't draw enough away from the battery when the engine is running at operating rpm then try a higher wattage bulb. If you add a switch then you could turn it on when the voltage starts to climb above 14 volts. A bit heath robinson I know but it would work.

 

Hope this helps you a bit.

 

Andy

[qd-16 14]

Jack, the only way I was able to resolve this issue on my 310 was to switch to a 15 amp stator, add a voltage regulator, and rewire the tractor.....it sounds like a lot of work but it fixed the

 

problem.  My motor was a k241.....Good luck!

[Wishin4a416 2,190]

Thanks everyone.

[Wishin4a416 2,190]

 

If adding one or two additional rectifier diodes in series with the original diode doesn't overcome the issue for you then you could try adding an additional load for the charging system to run which would be a simple version of the zener diode method. You could for example connect a 5 watt auto bulb via a fuse  to operate when the ignition is turned on. If this doesn't draw enough away from the battery when the engine is running at operating rpm then try a higher wattage bulb. If you add a switch then you could turn it on when the voltage starts to climb above 14 volts. A bit heath robinson I know but it would work.

 

Hope this helps you a bit.

 

Andy

Thanks Andy. I did read on the other thread about turning the headlights on to bleed off some voltage. So I tryed it and didnt notice any drop on the gauge but I didnt have it on the Fluke meter at the time either. I did say this was a fixer upper and one headlight was out and very shortly the other one blew. Like about 4 or 5 seconds after turning on. Coincidence, maybe,or the 16 volts and it couldnt handle it?

[Save Old Iron 1,565]

 

I strongly suspect that the aftermarket regulator Garry has drawn attention to would have consisted of a 14 volt power zener diode mounted on a finned heatsink and, unlike the rectifier diode, I doubt that it would have been taped into the loom anywhere as its purpose was to draw off the excess output from the alternator and turn it into heat.

 

Andy

Andy,

 

If I remember correctly, this kit was not too expensive (somewhere around $15). I always believed for that price it was just a IN type diode in a male / female connector arrangement. Simply separate the present wire harness and insert the new connector with a diode in series with the charge line. The last dealer I spoke with in regards to the kit remembered it as a "plastic piece" inserted in to the harness. Don't know much more than that.

 

The other thought I had about your zener shunt comment was in regards to the low energy content of the DC pulse at the peak charge voltage. The "area under the curve" of the DC pulse above 15 volts is likely small enough to allow a relatively small (5 watt??) zener to be used as a shunt without a heat sink.

 

What say you ?

[WH nut 553]

Its a good thing my volt meter doesnt work on my 310 or I might get scared lol

[wheeledhorseman 574]

Jack, as far as I know the lighting circuit on a 310 is A.C. and runs from a separate set of stator coils so turning the headlights on will not affect the charging circuit.

 

WH nut, while restling with this puzzle I can't help thinking of guys round the world mowing with this type of charging arrangement but no voltmeter. Ignorance is bliss, as they say!

 

Chuck, as I've never seen one I've no idea what exactly the aftermarket add on was so you may be one up on me with that one.

The problem for us is that, like 'Johnny 5' we 'need input' here. I think you've read my mind re the zener but I'm hoping that someone will confirm that a 5 watt auto bulb is enough load to pull everything back to sensible levels. If it requires much more than that then we're back to the 'what the' is going on here.

 

If it can be 'tamed' by this simple solution then based on the 'area under curve' a five watt zener would be more than adequate but ideally would need to be in 'free air' rather than bound into the loom.

 

I'm also hoping that someone will try a different ' known good' battery as originally one additional diode was seen as being enough to overcome the issue. I can't help thinking that the battery properties change as a result of the overcharging.

 

Another question came to my mind after making the posts last night. What type of battery are we dealing with on these machines that are throwing the overcharge issue? Is it a traditional wet lead-acid or is it perhaps a 'gel' type?

 

We'll get there in the end!

 

Andy

[Save Old Iron 1,565]

How about a 14 volt zener connected between the charge wire and the headlights? Whenever the charge exceeds the zener voltage, the headlights will act as a load dump for the excess charge. This would be similiar in concept to a zener in an "expanded scale" voltmeter. Nothing conducts until after the zener voltage is exceeded.

 

I agree about the gel or AGM glass mat batteries. They do need very different charger characteristics and I believe the final charge voltage presented to the fully charged battery IS CRITICAL. I'll need to look that up. I just acquired 2 AGM batteries from a guy who disassembles and sells pieces of the mobility carts seen at shopping malls. At $10 each, I took a chance to experiment with them.

[Save Old Iron 1,565]

Here is what I was looking for

 

"As with all gelled and sealed units, AGM batteries are sensitive to overcharging. These batteries can be charged to 2.40V/cell (and higher) without problem; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages). Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell), and a direct replacement with a sealed unit could spell trouble by exposing the battery to undue overcharge on a long drive."

 

http://batteryuniversity.com/learn/article/absorbent_glass_mat_agm

 

 

 

So once the battery is charged to (2,40 x 6 ) or 14.4 volts,

 

the voltage applied should be then be reduced and maintained at

 

(2.25 x 6 ) or 13.5 volts,

 

The fact the WH charge system is capable of exceeding 15 volts could be very difficult for a gel or AGM battery to handle.

[dsholler 54]

Virtually all marine systems these days are designed to accommodate gel or AGM batteries (they have some advantages in a boat). You should be able to find an appropriate regulator/inverter that will work for an AGM battery, although because it is "marine" gear it will probably cost a fortune.

[wheeledhorseman 574]

Still waiting to learn if there is / is not a link between these cases of overcharging and the use of batteries other than the original spec flooded (wet) type.

 

The traditional wet type is pretty robust and altough overcharging will reduce it's life by increasing the erosion rate of the postive plates in the cells, it will still have a reasonable working life though the electrolyte will need topping up from time to time. By a strange quirk of chemistry over charged flooded lead acid batteries are much less likely to suffer from sulfation.

 

On the other hand as Chuck has touched on, the life and performance of Gel and AGM types is drastically reduced by overcharging and to my mind neither are suited to LTs / GTs from the era we love.  Over charging a Gel battery has the effect of making the gelled electrolyte between the plates porous i.e holes in the electrolyte are created. This reduces a Gel battery's ability to deliver cranking amps, reduces the amount of charge they can hold and increases the internal resistance of the battery.

 

AGM batteries fair worse still in my experience if charged as though they were a flooded type. There is so little electrolyte held between the plates in the matting that the water content is rapidly lost if they are alowed to gas during charge and in a relatively short time the electrolyte dries out completely. I did once cut one open just to prove to myself that this is indeed what happens and found the electrolyte had been reduced to a dry crystaline powder.

 

Chuck, will send a pm re thoughts on zener diode in shunt mode.

 

Andy

[Wishin4a416 2,190]

I am using a wet type battery on its second year. I take it out of the 312-8 when I am fooling with the 310.

And Thanks everyone for the advice. I was going to stop at Radio Shack after work today but had second thoughts after reading that maybe we should be trying 6 Amp diodes so I will wait a bit.

Thanks again.

Jack

[catfish83 1]

My 310-8 is also overcharging.  I just replaced the battery with a new 230 CCA battery.  This is plenty for the 10 HP engine.  My tractor will start with a dead battery and a 50 AMP start boost from my charger. The battery I replaced only lasted less than three years which I believe is from overcharging  After I installed the new battery, I ran the tractor and measured 16.90 VDC across the battery terminals. It may have still gone up more but I didn't wait.  I tried three 15 AMP diodes in series with the built in charging diode and and ignition switch.  Voltage was still going past 16 VDC.  I decided to drill a hole in the control panel next to the head light switch and installed a toggle switch rated 3 AMP.  This switch was then wired in series with the charging diode.  I can now run the tractor until the voltmeter reads 14 VDC and then turn the charge off and periodically turn it back on to maintain 14 VDC.  I don't know why Wheel Horse never put a real voltage regulator in the 310-8.

 

catfish83

[rmaynard 15,298]

I would be tempted to install a 15 amp stator and a full sized regulator/rectifier if it were mine.

[woodchuckfarmer 333]

Im with Bob on this one

[WH nut 553]

If you got 3 years out of a garden tractor battery you did good.

[qd-16 14]

Installing a 15 amp stator and adding a voltage regulator was the only way I could remedy my overcharging 310-8.  No matter how many inline diodes I installed the stator would still put out 16 volts.

Edited March 8, 2014 by qd-16

[gwest_ca-(File Mod) 10,920]

Why couldn't one of these be added?

 

Garry

[Save Old Iron 1,565]

Garry,

 

that may just work. I'm not sure if that particular box has an internal diode along with the regulator. If so, you may have to remove the diode in the wiring from the WH stator.

 

Regardless, at $40 + shipping, that would be about half the price of making the 15 amp conversion.

 

I have resolved the overcharging in a 211-5 by inserting 2 extra diodes. Others have not had luck with the same fix. I believe the variability of the AC voltage from stator to stator makes the "extra diode" trick an uncertainty. Higher voltage stators would require more diodes and this quickly becomes a ugly hack with too many diodes needed.

Edited March 9, 2014 by Save Old Iron

[gwest_ca-(File Mod) 10,920]

I have one of these on a motor that I do not use the electric start on. I don't have a WH with a 3 amp charging system to try it on. Is there a way I can check to see if it has an internal diode?

The box I have is cast aluminum so suspect it is a heat sink.

 

Garry

[Save Old Iron 1,565]

. Is there a way I can check to see if it has an internal diode?

Probably check the wiring diagram for the engines this is used on. If the diagram lists a diode or shows a diode in the harness, then I would think this item is just a voltage regulator.

 

If no diode is seen in the harness, this item would most likely be a rectifier / regulator.

 

Otherwise, electronics test equipment would be needed to put an AC signal into the yellow lead and see what comes out of the Red lead.

[gwest_ca-(File Mod) 10,920]

I suspect this regulator has an internal diode as there is no other in the parts lists for this 190407-3125 8hp B&S engine that I can see.

 

This B&S chart has the regulator identified as H and this application is 5 amp.

 

They list a diode OR regulator in the chart 

691955 is a diode

691188 replaced by 794360 is the regulator

 

They are looking for 28 volts AC minimum at the stator.

Need to look and see if I have an AC transformer to test this.

 

Thoughts?

 

Garry