1988 310-8 Overcharging

[tunahead72 2,424]

I'm not done with this project, but I am making some small progress and wanted to post a quick update....

 

I installed the battery that was on this tractor on my '86 310-8, which has a very similar 3-amp unregulated charging system.  It started easily and ran pretty well for about 10-15 minutes at various RPM's, and my digital meter read about 17 volts at medium-high speeds, which is very similar to what I experienced with this same battery on the '88 tractor.

 

I then took that battery out and installed the battery that I've used on my other two tractors since about 2017.  Under the same conditions, my meter read about 14 volts pretty consistently.

 

My conclusion from all this is that the battery that came with my '88 tractor is defective somehow, as some of you guys suggested.  That's disappointing, since it's only about a year old, but at least it's an easy fix.  Just because I'm curious, I'll try to find someone who can do a resistance test on it.  I'll probably try my regular vehicle mechanic, and NAPA (rather than the two chains that are nearby).

 

I also noticed during all this testing that the volt meter on my '86 tractor read about 2-3 volts below my digital meter during the whole process, so I'm guessing it's just worn out.  I like having an ACCURATE volt meter on my tractors, so I'll think about replacing this one, but I'm wondering if there's any way to repair or rebuild it?

 

I'm working on the carburetor and other assorted goodies on this tractor, I'll let you all know how it turns out when I get everything back together.  Thanks for your help so far!

 

[Handy Don 12,237]

18 minutes ago, tunahead72 said:

I'm wondering if there's any way to repair or rebuild it?

Higher grade instruments sometimes have calibration adjustments but I would not expect to find one on a tractor-grade gauge.

 

If it were mine, being a curious person and open to buying a new one anyway, I'd open it up as carefully as possible to see if I could repair it. One warning--often internal leads that connect the inner instrument to the terminal posts on the case have no slack because of how the terminal posts were installed. I had one hour meter I was able to rejuvenate and one I had to give up on because I couldn't get the internal leads reconnected. Good luck! 

[WHX?? 48,833]

12 hours ago, tunahead72 said:

find someone who can do a resistance test on it.

Properly called a load test Ed. Usually any auto parts will do it for free. I know a batteries plus will for sure. This is a good tool to have for a herd of electric starts. Battery should have a full charge in it tho but if the battery in funked? 

 

https://www.harborfreight.com/100a-612v-battery-load-tester-61747.html

 

I have used an old skool demagnetizer, with limited success, that I had for demagnetizing tape heads in reel to reel & cassette players in the day. Sometimes voltmeters & amp gauges can retain some magnetism making them inaccurate. But like Don said about tractor grade gauges. 

https://www.amazon.com/Universal-DEMAGNETIZER-Cassette-Recorder-Track/dp/B003ZKLP4W/ref=sr_1_7?keywords=demagnetizer&qid=1649334262&sr=8-7

 

Prolly best to just replace it tho. If it's an unregulated charging system best to have a digital one for keeping a eye on battery voltage so you don't over cook it with long seat times. 

[squonk 41,162]

I'll pat myself on the back for suggesting the battery was causing your charging issue. 

 

As far as you getting different voltage readings on 2 meters, I have had several digital DVOM's read erratic on running horses. From Cheap Horror Freight ones all the way up to $400 Flukes. Also the gauges they used from the factory aren't the greatest either unless you see an "sw" on it. Anybody you know have a good analog voltmeter kicking around? You might end up trying to fix or repair that voltmeter and there is nothing wrong with it.

[lynnmor 7,310]

47 minutes ago, squonk said:

 

As far as you getting different voltage readings on 2 meters, I have had several digital DVOM's read erratic on running horses. From Cheap Horror Freight ones all the way up to $400 Flukes. Also the gauges they used from the factory aren't the greatest either unless you see an "sw" on it. Anybody you know have a good analog voltmeter kicking around? You might end up trying to fix or repair that voltmeter and there is nothing wrong with it.

 

For some of the primitive charging systems on tractors you can't beat an analog (needle) type of voltmeter.  The digital types jump around trying to keep up with peaks and valleys of voltage while an analog system basically can't react that fast and gives you the average of the voltage.  Just find an analog meter and check the voltage of a fully charged battery like in your car.  It is best to do the check hours after it hasn't been run and then the voltage should be 12.8, if it is close, then it it is good enough for any tractor work.

[tunahead72 2,424]

On 3/5/2022 at 10:57 PM, kpinnc said:

...There are battery testers for resistance that use AC to determine it. Most parts houses can test it...

 

3 hours ago, WHX?? said:

Properly called a load test Ed. Usually any auto parts will do it for free. I know a batteries plus will for sure. This is a good tool to have for a herd of electric starts. Battery should have a full charge in it tho but if the battery in funked? 

 

https://www.harborfreight.com/100a-612v-battery-load-tester-61747.html

 

I'm a little confused here... @kpinnc referred to a resistance test using AC, is that the same as a load test?  I actually have a load tester, very similar to the one @WHX?? showed.  I haven't used it on the suspect battery yet, but I can certainly do that.  Just wondering if you're both talking about the same thing?

 

I hear what everybody's saying about the digital vs. analog test meters.  My first couple of meters decades ago were analogs, and I see how they're different than the digitals.  I may pick up an analog meter someday soon, just to be able to compare results when the digital is giving me questionable information.

 

For now, at least until I get the '88 tractor straightened out, I'm inclined to leave the '86 tractor's volt meter in place, and understand that it's probably not giving me accurate readings.

 

Thanks guys!

 

 

[squonk 41,162]

There is a completely different tester used now days in conjunction with the load test. It is a resistance tester and the main purpose is to check to make sure there is no internal shorting going on. You can get a nice battery tester at Horror Freight for $70

 

https://www.harborfreight.com/digital-automotive-battery-analyzer-66892.html

 

[Handy Don 12,237]

14 minutes ago, tunahead72 said:

I may pick up an analog meter someday soon, just to be able to compare results when the digital is giving me questionable information.

For most of what I do, my DMM is perfect but if its readings are erratic, I pull out my old, basic Radio Shack analog as a cross-check (a lot like this one).

Usually, this is on the S/G with its mechanical voltage regulator or on simple diode-only systems like on my Techumseh Lawn Ranger, the 310-8, or B&S-powered Snapper, none of which have a built-in voltmeter. The Onan regulator is steady as a rock so the DMM is fine.

[tunahead72 2,424]

2 hours ago, squonk said:

There is a completely different tester used now days in conjunction with the load test. It is a resistance tester and the main purpose is to check to make sure there is no internal shorting going on. You can get a nice battery tester at Horror Freight for $70

 

https://www.harborfreight.com/digital-automotive-battery-analyzer-66892.html

 

Interesting tool, Mike.  I read the owner's manual on the HF web site, which mentioned that one thing that can cause high resistance is low electrolyte levels.  I haven't checked this battery yet, because it's a maintenance-free design, and only a year old.  The cap seems to be recessed into the case of the battery, like it's not supposed to be removed, but I'll take a closer look soon.

 

This begs the question, is there some reason I couldn't just do a simple resistance test across the two battery terminals, or is there something more complex going on with the tester you mentioned?

 

2 hours ago, Handy Don said:

For most of what I do, my DMM is perfect but if its readings are erratic, I pull out my old, basic Radio Shack analog as a cross-check (a lot like this one)...

 

Yeah, for $10 that looks like a worthwhile investment.

 

Thanks for the links, gentlemen!

 

[squonk 41,162]

Yes it's a little more complex. You can't measure resistance with say your DVOM because it would blow the internal fuse of the meter or worse. And you'll notice in the picture it's reading 4.10 Milliohms which is very small. I don't think a std DVOM can read that low. A milliohm is one millionth of an ohm not a million ohms

Edited April 7, 2022 by squonk

[lynnmor 7,310]

If a battery hasn’t been kept fully charged, especially if it was in freezing temperatures, can be wasted in a year.  A battery may age out in many years but neglect can do them in quickly.

[tunahead72 2,424]

3 hours ago, squonk said:

Yes it's a little more complex. You can't measure resistance with say your DVOM because it would blow the internal fuse of the meter or worse. And you'll notice in the picture it's reading 4.10 Milliohms which is very small. I don't think a std DVOM can read that low. A milliohm is one millionth of an ohm not a million ohms

 

That's good to know, and I'm glad you answered before I tried it.  I just checked my multimeter's instruction manual, and at best it has a resolution of 0.1 ohms, so not nearly sensitive enough.  Plus, I was reminded that resistance and continuity measurements are NOT supposed to be taken on a live circuit, which I guess is exactly what I would have if I connected my meter between the + and - terminals of my battery.  Thanks for saving me from myself!

 

Edited April 7, 2022 by tunahead72

[WHX?? 48,833]

Interesting Squonky never heard of a resistance test. 

3 hours ago, tunahead72 said:

 The cap seems to be recessed into the case of the battery, like it's not supposed to be removed, but I'll take a closer look soon.

They are glued in tight Tuna. I fear the days of checking electrolyte are over with. 

Remember the days of that vent with the little tube from the battery to the ground?!?! 

[dcrage 628]

Just for the sake of correctness: a MILLIohm would be 1/1000 of an ohm NOT 1/1000000 of an ohm

[tunahead72 2,424]

18 minutes ago, WHX?? said:

... They are glued in tight Tuna. I fear the days of checking electrolyte are over with. 

Remember the days of that vent with the little tube from the battery to the ground?!?! 

 

Another question answered, thanks Jim!  And yeah, I do remember the vent tube, still have one on my C-105 I think, it drips right on top of the mower deck as I recall.  Also have one on my motorcycle.  Damn, I need to get that thing running again, I'm jonesin' to ride!

 

[WHX?? 48,833]

Watcha got for a bike Tuna?

Funny I was just yakin about this on the phone yesterday with the Pullhosen @Pullstart about a battery in his scoot. He needs a new one. 

 He was wondering if he had to go get Harley batt or elsewhere. I told him to get a generic as a Harley dealer would have their trousers dropped  for the price of a battery.

@Achto paid $$$$$$$$ for a Harley batt for his diesel horse but it was the only thing that would fit for what he was doing. 

[tunahead72 2,424]

5 minutes ago, WHX?? said:

Watcha got for a bike Tuna?

 

... I told him to get a generic as a Harley dealer would have their trousers dropped  for the price of a battery...

 

'81 Honda CB750K, bought it in really nice condition in 2008, still in good shape, but needs for me to get off my arse and start fixing some things.  The problems started with a very strong gust of wind that caught it just wrong and knocked it over while it was parked in my driveway, definitely one of those loud "aww F***!" moments. 

 

You do have a way with words. 

 

[Achto 27,609]

11 minutes ago, WHX?? said:

@Achto paid $$$$$$$$ for a Harley batt for his diesel horse but it was the only thing that would fit for what he was doing.

 

I went with an Interstate battery for a Harley. Still wasn't cheap, about the price of a normal garden tractor battery plus a Benny.

[Handy Don 12,237]

1 minute ago, Achto said:

 

I went with an Interstate battery for a Harley. Still wasn't cheap, about the price of a normal garden tractor battery plus a Benny.

Yikes!

[Lee1977 6,673]

 

I'm late to this party. but  I can add what I know about the 312. Talking about grounds the dash panel is only attached by two screws usually rusted as well as the panel holes holding it in place. Can cause hard starting bad readings on the amp gage and hour meter that doesn't work. I add a few new ground wires cleaned the panel holes and screws got into that rat nest of wiring that wasn't attached to anything and just used what it took to make it run. Cut the rest out as most everything it was suppose to attach to was already gone.  But I'm old school use to equipment where the only safety device was the operator,

[tunahead72 2,424]

54 minutes ago, Lee1977 said:

 

... Talking about grounds the dash panel is only attached by two screws usually rusted as well as the panel holes holding it in place. Can cause hard starting bad readings on the amp gage and hour meter that doesn't work. I add a few new ground wires cleaned the panel holes and screws ...

 

You're talking about the lower panel, just above the shifter plate, where the volt meter, and ignition and light switches are located?  I never thought of that kind of panel as part of a path to ground, but I guess it is, isn't it?  I had that panel off in the fall, and I tend to clean out holes and screws/bolts with a wire brush when I have things apart, just because I'm ... particular, I guess.  It's good to know I'm improving grounds as well.  I'll keep looking for other areas to improve that way.

 

Thanks for the ideas!

 

[Lee1977 6,673]

2 minutes ago, tunahead72 said:

 

You're talking about the lower panel, just above the shifter plate, where the volt meter, and ignition and light switches are located?  I never thought of that kind of panel as part of a path to ground, but I guess it is, isn't it?  I had that panel off in the fall, and I tend to clean out holes and screws/bolts with a wire brush when I have things apart, just because I'm ... particular, I guess.  It's good to know I'm improving grounds as well.  I'll keep looking for other areas to improve that way.

 

Thanks for the ideas!

 

You also have the top panel that's bolted on is the ground path to the battery ground. Really bad design if stored outside for any length of time. Mine had been before I got it, never got the steering wheel off, had to cut the shaft.

[tunahead72 2,424]

Evenin' guys...

 

I just re-read this entire thread tonight, and just want to thank you all for your contributions so far.  I had to put this particular tractor on hold for a while to solve some problems with my other 310-8, but I think I have that one in good shape again for now, and should be able to work on the '88 early next week.

 

Just reading these posts again was an excellent review of where this tractor is at, and a great reminder of just how valuable this forum is to guys like me in keeping our old Wheel Horses alive and well.

 

Thanks again, I'll be back soon!