Overcharging TC-40

   / Overcharging TC-40 #1  

mphymel

New member
Joined
Aug 20, 2011
Messages
18
Tractor
TC40D Supersteer, 17LA
Here's a weird story that might help someone understand a similar issue in the future.

Mowing deer plots in September 21, we noticed a sulfur odor, an noticed that the battery was gassing off, to the point that we were afraid to pull the battery. Sent a guy into town and a couple of hours later we were back in business.

Fast-forward to June 22, and I'm back home mowing the field, and notice that odor again. Shut her down, popped the hood, and there was a slight sulfur odor and it seemed like there may have been history of vapor around the battery caps. I let it cool down for a couple of hours.

I go to restart, and..... nothing. Hike back to the house and get the jumper pack, and it starts. Soon after it flat dies at ~1800 rpm. Try to restart and nothing, now when hook up the jumper pack, I get a loud snap and nothing, back to the hous for the other jump pack, hook it in parallel with the first one, and no joy.

Puzzled, I get the wife's CRV to squeeze in between the fence and the machine and hook the jumper cables, after 15 minutes and several attempts, nothing. Negative cable at the starter housing positive on the battery cable at the battery. The car was providing current, my cables were warm when I removed them.

After mulling it over, my theory is the battery was shorted, to the point where when running it lacked voltage to keep the machine running.

Kudos to car quest (now advance auto) on honoring the warranty after going through an acquisition or merger. Put the new battery in, she cranks and got it back to the house before the rain started.

So the nagging question is why did it cook the battery. Overcharging would seem to be the most logical explanation. Hooked the meter last night, and initially everything looks good, but about 20 seconds after running up to 2000 rpm, the voltage went thru 14, to 16 volts in 15 seconds, I didn't wait to see how far it would go.
I suspect the high voltage somehow caused the battery failure, but exactly what the failure mechanism is remains a mystery to me.

So it looks like I'm in for a new alternator, as of summer 2022 ~$130 on Amazon. I'm sure someone will read this in two years and they will be running ~$650.

I hope I don't regret not buying this from my normal CNH suppliers.
 
   / Overcharging TC-40 #2  
You might check to see if there are any shops that rebuild alternators in your area.
 
   / Overcharging TC-40 #3  
If it has an external voltage regulator try replacing that first?
 
   / Overcharging TC-40 #5  
Here's a weird story that might help someone understand a similar issue in the future.

Mowing deer plots in September 21, we noticed a sulfur odor, an noticed that the battery was gassing off, to the point that we were afraid to pull the battery. Sent a guy into town and a couple of hours later we were back in business.

Fast-forward to June 22, and I'm back home mowing the field, and notice that odor again. Shut her down, popped the hood, and there was a slight sulfur odor and it seemed like there may have been history of vapor around the battery caps. I let it cool down for a couple of hours.

I go to restart, and..... nothing. Hike back to the house and get the jumper pack, and it starts. Soon after it flat dies at ~1800 rpm. Try to restart and nothing, now when hook up the jumper pack, I get a loud snap and nothing, back to the hous for the other jump pack, hook it in parallel with the first one, and no joy.

Puzzled, I get the wife's CRV to squeeze in between the fence and the machine and hook the jumper cables, after 15 minutes and several attempts, nothing. Negative cable at the starter housing positive on the battery cable at the battery. The car was providing current, my cables were warm when I removed them.

After mulling it over, my theory is the battery was shorted, to the point where when running it lacked voltage to keep the machine running.

Kudos to car quest (now advance auto) on honoring the warranty after going through an acquisition or merger. Put the new battery in, she cranks and got it back to the house before the rain started.

So the nagging question is why did it cook the battery. Overcharging would seem to be the most logical explanation. Hooked the meter last night, and initially everything looks good, but about 20 seconds after running up to 2000 rpm, the voltage went thru 14, to 16 volts in 15 seconds, I didn't wait to see how far it would go.
I suspect the high voltage somehow caused the battery failure, but exactly what the failure mechanism is remains a mystery to me.

So it looks like I'm in for a new alternator, as of summer 2022 ~$130 on Amazon. I'm sure someone will read this in two years and they will be running ~$650.

I hope I don't regret not buying this from my normal CNH suppliers.
If it was charging at 16V then you probably overcharged the battery. The alternator output voltage should be around 14.0-14.5 V. Most likely the voltage regulator failed.
 
   / Overcharging TC-40 #6  
When voltage regulators quit, they don't regulate. Simple as that. Nothing mysterious.
 
   / Overcharging TC-40 #7  
You might check to see if there are any shops that rebuild alternators in your area.
I would second this. Have not had alternators rebuilt, but have had starters done. Definitely worth checking out. They might also give you more insight in to why it failed.
 
   / Overcharging TC-40 #8  
You don’t have any voltage regulation. You shouldn’t see more than 14.5V. The more you rev the engine, the alternator will put out more power. Since the regulator is dead, the poor battery is getting cooked to death.
 
 
Top