Alternator not charging battery. Alternator, battery, and fuses all check out fine.

   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #51  
That was probably what was wrong with it. A alternator is not designed to charge a battery it just maintains it.
Sorry, I don't agree with that statement. While an alternators main purpose is to run all the on-board equipment under normal operation and maintain the battery, it also charges the battery if it goes flat. That is what it is for.
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #52  
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #53  
That is what I meant by maintain, it replace what is taken out by the headlights, starter, computer etc.



Fact: Alternators are not designed to charge dead batteries :: OPTIMA® Batteries
Sorry to argue the point with Optima battery folks, but most cars and trucks have at least a 100 amp alternator that is regulated to put out 14.6 volts when charging. I have used alternators many times to recharge a dead battery when lights or some other load has fully discharged the battery. You may damage the alternator if the battery is bad but I have never had a problem in 45 years of auto ownership and using the alternator multiple times to recharge a dead battery. They usually charge up in less than 30 miles of driving to full charge and enough to crank the car again in as little as 10 minutes if the battery is good and only accidently discharged. Not long back I had completely drained my truck battery by leaving my trailer (with electric brakes) hooked up, it wouldn't even run the radio or even a dash light, jumped it off and ran it 25 miles with charge at 14 volts according to the gauge. Stopped loaded up my tractor on the trailer, cranked up and headed home, about 10 miles down the road the ammeter went back to about 13 volts indicating battery was fully charged. Still using that same battery. This is at least 2 times this battery has fully discharged and several times it has set for 8 months at a time and discharged with the security system on to be so low it barely started. No alternator troubles.
Tractors have smaller alternators generally speaking than cars so it would take longer to charge, but I cant see it damaging the alternator as long as the voltage regulator is properly working, it wont overload the capacity of the alternator. It may be better on the battery to do a slow 6 amp charge like most battery chargers do, but so far it hasn't hurt the 2006 year made battery in my 2007 truck.
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #54  
That is what I meant by maintain, it replace what is taken out by the headlights, starter, computer etc.



Fact: Alternators are not designed to charge dead batteries :: OPTIMAョ Batteries

Really good point! Alternators are sized by the manufacturer to handle the anticipated load drawn off the battery when all loads are in use: headlights, dash lights, work light, etc. on a tractor. Even the loads through the fuses, which are rated to the wiring gauge, etc. It's done by an engineering formula and a certain amount of extra capacity is built in. This is where the voltage regulator plays a crucial part in the schematic of the entire wiring system. It's not even so much about the alternator as it IS about the battery; which is why I suggested at one point that even though the OP had been told the battery was fine, the rapid drop in voltage from it suggested otherwise. Now that all the data is in one can build the case for what happened. This is especially true due to clues like the battery being NEW in NOV. of '012.
FWIW here's what most likely happened: glow plug relay was on it's way out. Old battery and alternator could not keep up with the internal short, which kept draining the battery when the tractor was off. Relay would drain down the old battery until it could not be brought back by the alternator when the tractor was running. (Batteries are not meant to have a load on them UNLESS they are in a 'vehicle' that is returning used voltage, and slightly more, back to keep them in the fully charged state, while the vehicle is running and the alternator/Vreg are doing their job). So, old battery dies. New battery put on in Nov. Same problem persists because the CAUSE of the dead battery was never found and solved.
Most recently, 'Mom IS a mechanic' poses the problem here on TBN, and most of us scratch our heads online, (and then there's the guy who was scratching something, who knows what, and giving out rip off bills...).
Eventually, I suggested that she get a fresh battery in the circuit to verify exactly what was working and that led to the eventual conclusion through meticulous detective work on the part of the OP that a short in the glow plug relay,( indicated by constant clicking with the tractor off), EXCEPT when the glow plug fuse was removed; thus the problem was the glow plug relay malfunction, and it's constant load on the battery, that the alternator could not make up for when the tractor was running. One bad relay, two dead batteries later and the OP IS a mechanic!
Phew, what an ordeal. Goes to prove that persistence and checking everything twice is the way to solve difficult elusive electrical problems.:dance1:
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #55  
Sorry to argue the point with Optima battery folks, but most cars and trucks have at least a 100 amp alternator that is regulated to put out 14.6 volts when charging. I have used alternators many times to recharge a dead battery when lights or some other load has fully discharged the battery. You may damage the alternator if the battery is bad but I have never had a problem in 45 years of auto ownership and using the alternator multiple times to recharge a dead battery. They usually charge up in less than 30 miles of driving to full charge and enough to crank the car again in as little as 10 minutes if the battery is good and only accidently discharged. Not long back I had completely drained my truck battery by leaving my trailer (with electric brakes) hooked up, it wouldn't even run the radio or even a dash light, jumped it off and ran it 25 miles with charge at 14 volts according to the gauge. Stopped loaded up my tractor on the trailer, cranked up and headed home, about 10 miles down the road the ammeter went back to about 13 volts indicating battery was fully charged. Still using that same battery. This is at least 2 times this battery has fully discharged and several times it has set for 8 months at a time and discharged with the security system on to be so low it barely started. No alternator troubles.
Tractors have smaller alternators generally speaking than cars so it would take longer to charge, but I cant see it damaging the alternator as long as the voltage regulator is properly working, it wont overload the capacity of the alternator. It may be better on the battery to do a slow 6 amp charge like most battery chargers do, but so far it hasn't hurt the 2006 year made battery in my 2007 truck.

I would agree with you that alternators CAN and do recharge what seem to be dead batteries. However in the OP's case she clearly had the two deadest batteries in the known universe.
It seemed to me from what she said that the first battery had been replaced because it was no longer taking jump starts, and in Nov.'012 they replaced it with another fresh battery, which lasted admirably until just recently.
You give examples of draining batteries to a no charge state and then jumping them to then use the onboard alternator/regulator to bring them back to life. This can and does work, EXCEPT the OP's case is different. From the time of insertion of the second battery the dead short in the glow plug relay never allowed the new battery to regain a full charge. It, the drained battery AND the shorted glow plug relay, were constantly drawing so many amps out of the alternator that it could not provide the necessary output for a long enough time to bring the battery back to a fully charged state. Basically it could not overcome the combined load of the relay's draw and the battery's marginal state of minimum charge. With your vehicles you would find the battery dead and correct the drain, headlights, trailerbrake, whatever, and then have a NO LOAD condition for the alternator to correct, except for recharging the jumped battery. This was not a constant drawdown of your battery to a state of near complete discharge.
I do disagree with Optima's statements about alternator damage occurring, as if it always is a problem when trying to recapture a marginal or deeply discharged battery.
More later- 'gotta run out....

I'm back now - additional factors play into the entire scheme of battery failures or 'potentially' dead conditions. One is specific gravity- a measure of the electrolytic level of each cell in a conventional wet cell battery. Without each cell having enough water and acid a battery can end up with one or more sulfated cells, rendering it unable to handle the loads placed on it by the car, truck, tractor, boat, etc.'s electrical system. Water in the electrolyte mix of wet cell batteries can and will evaporate over time, especially in high heat conditions in various parts of the country. If caught in time distilled water can be added to bring the level up to the split ring level in each cell.
Another factor is a properly run load test, to determine the exact state of the battery's ability to handle a load of a certain # of amps for a specific time frame.
Without these tests being properly executed it's anybody's GUESS as to what a battery can or can't do under load in a vehicle of any type.
Years ago when I had my foreign auto shop I owned a Snap-On load tester and it worked great in determining if a battery was marginal or in need of replacement.
 
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   / Alternator not charging battery. Alternator, battery, and fuses all check out fine.
  • Thread Starter
#56  
Tractor is still chugging along just fine. If it so much as hiccups, I freak and get the meter back out but so far all is well!

I got on here so I can write down everything that was suggested and show what I did and when. Husband keeps detailed logs on all work performed on each piece of machinery and vehicle. This helps subsequent buyers if we ever go to sell something. That is when I found the new posts. Yall are absolutely wonderful and I truly could not have done it without you. Thanks again guys!
 
   / Alternator not charging battery. Alternator, battery, and fuses all check out fine. #57  
"Husband keeps detailed logs on all work performed on each piece of machinery and vehicle. "

Great way to go, keep that up!!

Glad to hear it's running OK; again, you did good! I'm sure hubby will appreciate the log entries you make, too. (Or, you could let him put in what he wants to, just give him a "report"... sometimes we guys get rather persnickety about that stuff!:laughing:) WBB
 
 
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