Electrical/Battery issue

[Silvic]

I have had an intermittent electrical issue for several months. It manifests itself as a battery problem when the machine will not turn over. The battery was checked by three places in June and all said that it was working at 95% or above. After fighting with it for a week the problem evaporated for nearly 3 months. I ran it on Thursday and it started normal. On Friday problem is back.

I have cleaned every terminal and wire and connection that I can find from the battery. I have cleaned the terminals of the mini fuses. I do intermittantly hear relays clicking back and forth but it is intermittant, other times nothing. Thinking well let's fully charge the battery anyway. It was at 12.4 volts after a bunch of putzing with the system. Fancy desulfating charger never got it above 25% charge on the lights but the voltage was 12.8 once removed from the charger. Tried 2A/6A charger and it shows no current into battery. Tried OLD (37 years) battery charger that pulse the analog meter when fully charged and is steady at some amps when charging. It sits at zero amps. It hums and the voltage at the battery is 14.9 volts when hooked up.

I have never heard of a battery that can show proper voltage for being charged 12.8 volts but has no power to even turn the motor. Also I have never seen the chargers act this way with a battery, new, old, dead etc.

I do not pretend to be a battery guru but I am at a loss. Any ideas what this battery has going on that it does not even show a current on the charger.

Not that it probably matters but it is a JD 4720

 

[Roadworthy]

You say the battery was checked by three places. Did any of them do a load test on a fully charged battery? Do not rely on a simple test with a voltmeter. Get a load test - generally free at an actual battery shop. Fully charged, a battery is normally about 12.6 volts. Freshly removed from charger it can show higher for awhile until surface charge dissipates. If connections are good and battery is good from there you should check the tractor's charging system (voltage on battery should be about fourteen volts with engine running). Depending on your situation it might be good to see if you're experiencing any parasitic drains on the battery with the engine not running. This can be determined by disconnecting one lead from the battery and inserting an ammeter into the circuit. If the tractor has a computer you may have some drain but it should be under an amp.

 

[grsthegreat]

actually, there is a wide range of charts related to lead acid battery voltages. From my work on home standby generators, i find a fully charged battery can be as high as 14.2 VDC, but usually around 13.5 volts. i dont see how a battery showing 12.8 volts wont power anything. i agree a load test is required. also place a standard volt meter across battery terminals when trying to start and see what readings are. i see batteries that read 12.8 votls drop to 8 volts while cranking engine.

 

[CobyRupert]

Did you also check and clean where the (-) ground cable from the battery connects to the frame? This is a common source of resistance.
Do a battery load test.
Either with a battery tester or see what the voltage drops to while you’re starting.

 

[jaxs]

I would try booster cables when the problem surface's. If it still doesn't turn engine,you have a bad starter,ignition switch,start button,broken wire or have overlooked a poor connection. Inversly you might try battery on some other machine.

 

[stevem5215]

The battery could have a surface charge and show good but have no capacity available in reality. Put a jumper pack on it and try starting it. If it starts it's the battery.

 

[CoyPatton]

Not sure what all terminal ends means, however a couple of places to check in addition to load testing the battery would be the ground cable at the frame and the positive cable at the starter.
Also you may wish to remove the starter from the housing and clean the mating surfaces. The starter grounds through this connection. I have made a grounding strap from a starter bolt to the frame when issues with starter grounding occurred. You can test this with booster cables by grounding the starter directly. Often on tractors, I will jump them using the battery terminal at the starter and a starter mounting bolt for a ground.

 

[Silvic]

You say the battery was checked by three places. Did any of them do a load test on a fully charged battery? Do not rely on a simple test with a voltmeter. Get a load test - generally free at an actual battery shop. Fully charged, a battery is normally about 12.6 volts. Freshly removed from charger it can show higher for awhile until surface charge dissipates. If connections are good and battery is good from there you should check the tractor's charging system (voltage on battery should be about fourteen volts with engine running). Depending on your situation it might be good to see if you're experiencing any parasitic drains on the battery with the engine not running. This can be determined by disconnecting one lead from the battery and inserting an ammeter into the circuit. If the tractor has a computer you may have some drain but it should be under an amp.

All three places performed a load test. Battery efficiency by their load tester showed from a low of 95% up to as high as 97%. All three places verified that there was nothing wrong with the battery. The JD dealer even had one of the old style carbon pile testers that noone else has anymore.. The rest used the fancy new load testers that are about the size of a small suitcase. I kept changing to a different place as I was convinced that the battery had to be the issue back in June. Tractor charging system is fine. The battery had never since the June event dropped below 12.4 volts even after trying to get the tractor to start.

I did a parasitic drain test back in June and also yesterday and there is no drain on the battery with the key off. I suspected that a relay may have stuck back in June and drained the battery in that one case,

actually, there is a wide range of charts related to lead acid battery voltages. From my work on home standby generators, i find a fully charged battery can be as high as 14.2 VDC, but usually around 13.5 volts. i dont see how a battery showing 12.8 volts wont power anything. i agree a load test is required. also place a standard volt meter across battery terminals when trying to start and see what readings are. i see batteries that read 12.8 volts drop to 8 volts while cranking engine.

Load test done by all three places that tested it. Surface charge on the battery back in June was 13.6 after coming off the charger. Battery has no drop at all when the key is turned to run or start. Of course there is nothing other than relays clicking. (not the starter relay). Don't know what relays I am hearing might be fuel.

Did you also check and clean where the (-) ground cable from the battery connects to the frame? This is a common source of resistance.
Do a battery load test.
Either with a battery tester or see what the voltage drops to while you’re starting.

Yes I cleaned the frame ground with emory paper and all positive and negative cable connections.

I would try booster cables when the problem surface's. If it still doesn't turn engine,you have a bad starter,ignition switch,start button,broken wire or have overlooked a poor connection. Inversly you might try battery on some other machine.

Back in June I previously tried a different battery, different ground and power cables. Yes I also tried to boost with another battery at one point as well. I took the battery and hooked it up to a 12 volt halogen light and ran it for 6 hours and it had no issues then either.
Of course that is all ancient history as that was back in June.

The question no one has addressed yet is the question as to what might cause all three battery chargers to show no current charging the battery. Hard to believe all three of my chargers have failed in their indication capability on current flowing into the battery. I actually tested all three on a car installed battery and they showed current flow so they are not broke. On this battery there is no current flow into the battery from any of the three chargers.

As an aside the tractor started just fine this afternoon as if nothing had ever been wrong. The battery chargers are still acting the same on the battery even after I shut the tractor off Gremlins on the tractor. Battery I just don't know why it appears not to have current going into it from the charger.

 

[Silvic]

Not sure what all terminal ends means, however a couple of places to check in addition to load testing the battery would be the ground cable at the frame and the positive cable at the starter.
Also you may wish to remove the starter from the housing and clean the mating surfaces. The starter grounds through this connection. I have made a grounding strap from a starter bolt to the frame when issues with starter grounding occurred. You can test this with booster cables by grounding the starter directly. Often on tractors, I will jump them using the battery terminal at the starter and a starter mounting bolt for a ground.

What I mean by terminal ends: Both battery post terminals. Also: the ground terminals (5 in total) that join at the frame ground post. The positive terminals that join at the starter post (5 in total as well). I cleaned the contacts at the fuse boxes the fuse terminals and the relay terminals at the fuse box. (start and fuel relay). If it was the starter ground I don't think the instrument display would fail to illuminate when the key is placed in the run position as if there was no power. Relays do click/cycle however.

However as I posted above problem has "magically" disappeared again. Except for the battery and battery charger anamoly.

 

[grsthegreat]

Now, have you checked ignition switch. By this I mean use a voltage tester to see if switch is completing circuit when key is turned. I know open station Kiotis are known for this issue, not sure other brands don’t suffer the same fate.