I Am Also OverCharging

[boovuc 1,090]

What the H@#ll is going on here. I'm overcharging again!

Earlier this Spring I also was overcharging on my 310-8. Same issues as what has been posted before. (Two very recent posts. Mine makes three). Creeps up to 16 VDC or more. Confirmed the high voltage with a VOM. I too added diodes. Three to be exact, and it was OK for a little while but it is right back to where it was before. 14 VDC on starting then creeps up to +16 VDC. (Quickly once it starts to rise). Here is an observation noted..........once that voltage gets to 16 VDC, it stays there! Even at idle. The diodes in the harness are warm to the touch.

Does anyone have any other fixes other than a conversion? If not, steer me in the right direction with what I'll need to do the job. This is my #1 mower and I really want it back to operational without worrying about frying my battery plates and blowing sulphuric acid over the back side of my tower.

Thanks!

[wheeledhorseman 579]

Understand your frustration and I'll try to help solve this if I can because the whole issue intreagues me now.

 

Can I get you to try a couple of things and report back.

 

A degree of regulation in these simple systems is achieved by a kind of balancing act between alternator and battery. In theory the stator coils are unlikely to change their properties but the characteristics of a battery can. As a battery ages it's internal resistance rises and I'm beginning to wonder if overcharging doesn't significantly add to this effect over time.

 

If you put the battery from one of your other tractors in the 310 what does the voltmeter do?  No need to leave it in there for long but just long enough to see if there's a difference.

 

The second thing to try with the original battery in place is to add a load to draw some of the excess charge away from the battery. Start with something like a 5 watt auto bulb connected to the battery via a fuse for safety. You could hook it up to get its power from the non-points side of the coil and a suitable earth. Does the votmeter reading decrease? If it does but not by enough you could try a higher wattage bulb.

 

The fact that you had to add three diodes in the first fix tends to indicate that things had got well out of balance for whatever reason.

 

Let me know what you find and I'll try and interpret the results. Also is it possible to check the electrolyte level in the battery?

 

Andy

[Save Old Iron 1,568]

I don't recall what part # diodes you used to modify the charge system. It is possible if you used 3 amp diodes, one or more of the diodes could have overheated and shorted, essentially bringing you back to the original operating conditions (overcharging).

 

Do a forward and reverse resistance check on EACH DIODE to see if any are shorted out after being on the tractor for several weeks.

 

 

 

 

As Andy stated, battery condition does play a role here. A highly sulfated battery will start to show a rapid rise in terminal voltage as it presents a much smaller load to the charge system than a healthy battery.

 

I talk about it ...

 

I even "badger" folks about it....

 

 

 

 

a 50 amp load tester for lawn and garden batteries is a first line of defense in diagnosing these types of issues where battery condition can be a surprsiingly big factor.

[boovuc 1,090]

The diodes I used were the same from radio shack that were recommended in an earlier post. I have used three batteries in the tractor. A one, two and three year old all in working condition and the last battery I put on it yesterday was fully charged. All three exhibited the same issues in the same amount of time. (None were ever over-charged).

When I turn on my lights..........the voltmeter nor my VOM even move or flinch. (I thought this was really strange). Normally on any charging system, when you place another load on the system, you'll get a quick dip in voltage. Again, when the tractor's lights are turned on, my VOM and the dash's voltmeter do absolutely nothing!

I even used heatsinks while soldering the diodes in-line. I do wonder if I have a failure of one. I also wonder about keeping the original equipment "component" in that line since it most likely failed and caused the issues that necessitated adding the diodes.

Really frustrated with what should be an easy diagnoses and fix. And it appears I'm not alone!

Thanks for the help, guys!

[Save Old Iron 1,568]

When I turn on my lights..........the voltmeter nor my VOM even move or flinch. (I thought this was really strange). Normally on any charging system, when you place another load on the system, you'll get a quick dip in voltage. Again, when the tractor's lights are turned on, my VOM and the dash's voltmeter do absolutely nothing!

 

Actually, that is perfectly normal.

 

The winding on any dual voltage stator for the headlights is an ENTIRELY SEPARATE winding from the charge winding. Neither winding has any interaction with the other. The headlights never draw power from the battery - ever. When you turn on the headlights, they draw power off the totally independent 2nd winding of the stator.

 

This is one of those issues my instructors warned me about.

 

That which seems complex can be very simple. That which seems simple can be quite complex.

 

I'm going to pull the 212-5 from the barn to check a few things to see if I can help out. In the mean time - check those 3 amp diodes - each one - should show distinct forward and reverse resistance readings. We may need to go with 6 amp diodes if the 3 amps versions prove too weak to sustain the current and ambient temperature conditions inside the harness next to the engine.

[boovuc 1,090]

I'll unwrap the wire later this week given time SOI and Andy. I appreciate the help with it. I'll assume, (boy I hate to use that word), that I can check the resistance simply by crossing the actual diode with the VOM while they are still in series on the wire?

 

I'm really glad I didn't heat-shrink that wire. I was going to but forgot to run my closed loop of shrink tape on the wire before I soldered the last one in!

[boovuc 1,090]

Boy did I use a lot of tape!

Each diode appears to check out OK using the diode check function on the VOM. (Also resistance reading on auto ranging gave a half-scale resistance and none when reversed). Even the original equipment diode appeared to be OK! As a last resort I'm going to take the battery from the 520 which I know is (1) new and (2) charged up, and see if it acts different. Both batteries I recently used are the same cheap Wal-Mart batteries each about one and two years old. The other battery I used is an old Huskie 320 which may have been drained and is old. One of the newer Wal-Mart batteries I tried came from a friend's MTD that is a year old but for all I know, his little 3 AMP system may be welding plates on it. (No idiot light or gauge on it if it was).

I'll get a bulb holder and bulb and see what bleeding off a little current does possibly this weekend.

I have the blower on the C-175, the 867 is in the shed and just sitting pretty and my 416 is in another town taking care of the grass of a friend who once owned that MTD! Thank God for the 520! All these horses and I have one mower! Maybe I need another tractor!?! 

[boovuc 1,090]

I think I figured it out and many thanks to Andy and Save Old Iron.

The two batteries I have that were new in May of 2011 and 2012 are bad. I hooked both of the batteries up to my digital Schumaker charger with a digital readout of % battery charge or charge voltage.

Each battery show they were at 95% charged on the 2 amp small battery cycle. But................when you looked at the voltage, they started at 13.5 VDC and it climbed steadily to 16.1 VDC after 30 seconds. On top of this, they never ever climbed to 100% charged. In fact, they never left the initial 95% charged. I left both on for 15 minutes. (Didn't want to go longer due to the input voltage they were receiving).

Next, I charged a 7 year old Husky 300 crank battery that is actually still charging and holding a charge well. It was on my bench and was at 60% charge. At 2 AMPs this battery never climbed above 14.1 VDC and actually wavered between 13.9 and 14.1 VDC. When it reached 90% charged, I took it off the charger and placed it in the 310. I ran it around for about 5 minutes and the voltmeter on the tractor's dash never went above 14 VDC.

Now how many of the recent folks having this issue actually do have a wacked out battery. (These are the cheapo Wally World units). I have two of them and should have lasted longer than this!

[Save Old Iron 1,568]

Excellent followup Boo.  Battery badger strikes again !

 

Check your $%#^^ batteries!

 

This is the "balancing act" Andy spoke of. The batteries were no longer absorbing any significant energy from the stator and the energy remaining in the charging system exposed itself as a higher than normal charge voltage.

 

Read up on battery characteristics. These devices should not be considered "bolt it down and forget about it".

 

 

There is one mystery still left - I inherited a Scotts (Deere) 17hp vert back in 2001 when my dad died. The original battery is still in this tractor. The battery is marked Briggs and Stratton so I'm not sure of the manufacturer.

 

NEVER had the battery out of the tractor.

NEVER had to clean the battery terminals.

 

The only extra care I have taken is to put a small solar panel charger on the barn and keep the batteries charged thru the winter. On some batteries it has worked (apparent) miracles. On others, not so much. .

[Save Old Iron 1,568]

An after thought.........

 

wouldn't it be interesting to hook up a voltmeter to one of the "bad" batteries and measure the time it took to drain the battery to below 10 volts.

 

you could use a headlight or any other suitable 12 volt higher current device to load down the battery.

 

you may be surprised to see how little energy is left in the bad batteries even tho the terminal voltage reads OK.  Remember that terminal voltage means very little in real world operation. Not nothing ... but very little. Capacity has significant real world effects.

 

Battery badger signing off for the night.

[boovuc 1,090]

That isn't a bad idea. I'll give it a shot when I'm in the garage for a period. Load a little Pink Floyd Momentary Lapse Of Reason and hook a bulb to the batteries and see how much charge they have left. Now to find a good battery without taking out a second mortgage.

PS..Andy, the electrolyte level in all the batteries I danced through this tractor were good. The third battery, a very old Husky 300+ cranker from 2003 had slightly lower levels that I topped off with dehumidifier water. It exhibited the same issues as the newer Wally batteries. (But that was a battery that should have been retired and now is). The one I have in the 310 now is what I use for the C-175. All my batteries are removed in the winter and moved to the basement after they are topped off on the charger. I have kept many batteries for 3 to 5 years and the Huskies beyond that. No more WM batteries for me.

[Wishin4a416 2,191]

Glad you got it worked out Boo. I looked at my Battery this morning and it is older than I thought.

It is a 2-11 battery and Duro-Last is the Brand. Tractor Supply maybe. Anyway it works great in the 312 because it is regulated I guess.

I am not going to get a Battery for this one yet as I have to find and change the rearend out first.

When I get a new battery I will post the results. This will be a dedicated snow plow tractor so I am in no real hurry [Yet].

Thanks

Jack

[wheeledhorseman 579]

Glad that it's now a case of mystery solved and thanks for patiently working through things and reporting back which has helped us solve the mystery of the rising charge voltage.

 

The fact that the electrolyte level wasn't down is also an indication the the battery wasn't taking any real charge as if it had been over-charged for some time I would expect some of the water content of the electrolyte to have been 'boiled off' and the level down a bit.

 

As an experiment I tried a cheap battery obtained online for my daughter's car. Including delivery it was much cheaper than anything I could get locally. Claimed to be 'heavy duty' and all that, but come the second winter it wouldn't crank the engine. I'm not saying all cheap batteries are complete cr&p but certainly some are poorly built internally and savings have obviously been made on the materials used to construct the plates. Go up market and the odds become more in your favor but I've had the odd big name brand give out prematurely as well.

 

I see you started a post looking for advice on what brand battery to use. What I will say is that I don't think too much of the blame here lies with the unregulated charging system. Sure, a with a regulated charging system you wouldn't have seen the voltage rise above 14 volts but the battery still wouldn't have been taking much charge. I have this issue with one of my tractors where I bought a cheap battery that has now done just two years but holds little charge  to the extent that with a lot of stop - starting as it's used to pull a trailer about it reaches a point where it won't crank the engine. Put on an old school charger and left to bubble away for a day it's then good for another two to three weeks. My modern charger with LEDs, float charge etc is no good for this as it tells me that the battery is fully charged after just a few minutes and puts it on float charge. I need a new battery but I'm just stubbornly gonna get at least three years out of it!!

 

All the best

 

Andy

[gwest_ca-(File Mod) 11,289]

I recall reading about overcharging on the 200-Series but could not remember where. Seems overcharging has been a problem for a while. Read the last paragraph on the 2nd page

 

Garry