Battery won’t keep a charge

[Jacob S 67]

My c81 wheel horse will not keep a charge. The battery is fairly new and  we have changed the alternator thinking that it would take all the energy from the battery but still it would not keep a charge. Then we sanded the back down of the regulator thinking it was a bad ground but it still does not hold a charge . If any one can help thanks.

Edited November 17, 2021 by Jacob S

[ebinmaine 67,671]

Do you have a voltmeter?

 

Have you tested the actual output of the alternator?

 

[WHX?? 48,833]

Any chance you got a DOA battery? It happens more often than not the way things are made nowadays.

 Any chance you have a parasitic draw? Easy to check this. Charge the battery and measure the voltage while still connected to the tractor and monitor the voltage. If VDC drops disconnect it and charge it again and monitor again if it drops when disconnected might mean a bad battery. Record all measurements.  If it holds it voltage might mean a parasitic draw. 

Also charge the battery and check the voltage and record it. Run the tractor and see what the voltage is when say half  and full throttle. Again record all measures and report back. Of course you will need a DMM for all of this. 

A $20  load tester from HF can eliminate bad batteries from trouble shooting efforts. 

 

Your on the right track by checking all connections and grounds.

Edited November 17, 2021 by WHX??

[SylvanLakeWH 25,604]

In addition to above, if you don’t want to do it yourself you can get the battery load tested for free at an auto parts store…

[WHX?? 48,833]

good idea Sylvia forgot about that. 

Edited November 17, 2021 by WHX??

[Darb1964 1,044]

I just went through the same thing with my c-81. Drove me out of my mind, finally put a new ground wire from the battery to the frame. That was a few weeks ago and I've run it six or seven times since then and the battery stays charged. A brand new battery would draw down in about a half hour to the point where there wasn't enough power to keep it running.

[Jacob S 67]

Ok I have a voltmeter and my dad was showing me how to use it and I will do that tomorrow. We have had the battery for 2 years and it works fine it just does not hold a charge. I will do all of this tomorrow and share the results with you guys. Thanks 

[lynnmor 7,309]

12 minutes ago, Jacob S said:

We have had the battery for 2 years and it works fine it just does not hold a charge.

A battery needs to be kept fully charged for it to last.  If you allowed the battery to get below a 50% charge for an extended period of time, it may be wasted.

[Jeff-C175 7,202]

3 hours ago, Jacob S said:

works fine it just does not hold a charge

 

Well... part of a battery 'working fine' is that it holds a charge.  So really, it doesn't 'work fine'!  

 

 

[ebinmaine 67,671]

7 hours ago, Jacob S said:

battery for 2 years

The shop I get some of my parts from has told me that a late model lawn and garden battery should last 3 to 5 years IIFF it's maintained right. 

They so see a LOT of batteries 2 years old that are trash. 

 

 

How long does your existing battery hold a charge?

 

[wallfish 17,014]

6 hours ago, Jacob S said:

Ok I have a voltmeter and my dad was showing me how to use it and I will do that tomorrow. We have had the battery for 2 years and it works fine it just does not hold a charge. I will do all of this tomorrow and share the results with you guys. Thanks 

Batteries DON'T last like they used to so it's certainly plausible that a 2 year old battery has crapped the bed. I've had some last only one season! I also have the same make battery tagged 3/12 still starting and running an 8hp engine. Luckily that engine fires up quick as the battery is definitely tired but.... 2012 makes that an antique battery. LoL

Check the voltage on the battery with the engine running to verify the charging system is in fact actually charging. Typically it should be about 14 v ish.

If it's not charging there's your problem to start with. If it is charging then the battery is most likely the problem. Although Jim has mentioned parasitic drain above.

If it isn't charging, set the meter to AC voltage and test the 2 wires coming from the stator that go into the regulator. With the engine running those should test up in the 30 volt range AC. No AC voltage = something wrong with the stator. If the voltage is good then set meter to DC and test the 3rd wire on the regulator which is what is supposed to be charging the battery. Should be 14 V ish DC. If the AC is good and DC is not then the regulator is the problem. If DC is good at the regulator but not at the battery then troubleshoot the wiring.

[gwest_ca-(File Mod) 11,050]

9 hours ago, Jacob S said:

Ok I have a voltmeter and my dad was showing me how to use it and I will do that tomorrow. We have had the battery for 2 years and it works fine it just does not hold a charge. I will do all of this tomorrow and share the results with you guys. Thanks 

One more test you can do with a voltmeter if you have an extra hand.

Put the black lead to a clean bare spot on the tractor frame.

Put the red lead to a clean spot on the engine without any rust. Ideally the cast iron block or the carburetor.

Try the starter and see if you get a voltage reading.

If you do you just measured the voltage drop across a short ground cable between the engine mounting plate and the tractor frame which provides a chassis ground. This will affect the voltage regulator.

You want a zero volt reading.

The short ground cable often breaks from vibration because the engine is mounted on rubber.

 

You can do the same test between the body of the aluminum regulator and the negative battery post. It requires a good ground to function properly which is a zero voltage reading.

 

Another - Negative test lead on battery (-) post. Slide the other lead across the top of the battery toward the (+) battery post. If you get a voltage reading the top of the battery is wet and causing a short between the battery posts. The wetness may be battery acid so clean the meter leads to prevent corrosion. Hands also because it eats clothing. A mixture of water and baking soda will neutralize the acid. Clean battery and dry it.

[squonk 41,161]

[peter lena 8,639]

@Darb1964 agree with that added grounding , run a 4 ga , wire from my battery ground point , serrated washers , dielectric grease , to lower engine corner / frame , by clutch pedal , from there with 12 ga wire to rectifier bolt mounts on engine shield , and from that to headlights , like having a main line ground set up . have that on my 3 horses , no more electrical problems , works for me, pete 

[Jeff-C175 7,202]

I would put the battery on a known good charger and then check specific gravity to see if it actually did take a charge.  Use a HYDROMETER for this. Decent ones can be had for under $20.

 

And get the battery load tested AFTER it is fully charged.

 

Only then would i start looking at the charging system on the tractor.

 

Always look at the WEAKEST LINK (the battery itself) first.

Edited November 17, 2021 by Jeff-C175

[wallfish 17,014]

But, the charging system can be verified with a volt meter to know for sure if it's actually working or not in less time than it would take to fully charge a battery. If the charging system isn't operating, it won't really matter how good a battery is.

Verify the charging system while you're waiting for the battery to fully charge and kill 2 birds with one stone, especially since you did some prior work on the stator.

[Jeff-C175 7,202]

2 hours ago, wallfish said:

charging system can be verified

 

True that, in about 30 seconds!

 

[Jacob S 67]

I charged that battery and then read the volt meter and it said 12.70 and then I let us run for a bit and it was going down 2 every minute. Then I took the ground off the tractor and sanded it off and then ran it and it went up a little then down again. 

[wallfish 17,014]

Going back up is just the battery recovering

OK What about testing the stator / Charging system as suggested above?

The charging system doesn't appear to be operating from what you are describing

 

If it isn't charging, set the meter to AC voltage and test the 2 wires coming from the stator (from behind the flywheel) that go into the regulator. With the engine running those wires should test up in the 30 volt range AC. No AC voltage = something wrong with the stator. If the voltage is good then set meter to DC and test the 3rd wire on the regulator, which is what is supposed to be charging the battery. Should be 14 V ish DC. If the AC is good and DC is not then the regulator is the problem. If DC is good at the regulator but not at the battery then troubleshoot the wiring.

[sparkie333 265]

3 hours ago, Jacob S said:

I charged that battery and then read the volt meter and it said 12.70 and then I let us run for a bit and it was going down 2 every minute. Then I took the ground off the tractor and sanded it off and then ran it and it went up a little then down again. 

 

I think you may have answered you own question----you said that you took the ground off =--then you got a good reading for a while--well now you know the connecting is clean----but you moved the ground wire around moving it may have made a better connection on a wire that is breaking down on the inside---you may wish to put on new ground wire---Just saying---

[WHX?? 48,833]

Star washers can help with grounding or just about any electrical connection Jacob.  They "bite" into the connections