Ok all you mechanics ,or want to be mechanics...I have a woods 3 cyl. diesel mower that I have had to replace the battery in for each of the 2 yrs I've owned it..At idle the battery voltage is about 13.5 volts.at full throttle the voltage is about 14.5 volts.This indicates to me that the altenator is working , but my question is whether the voltage reg, is shutting off the charging cycle when fully charged. Clamp on amp guage on the battery cable reads 3.5 amps all the time. batteries have been dry on both end cells when I checked them.Could it be that the charging system does not quit , and overcharges the battery causing it to boil dry?By the way, this application is a woods 6215 , with a 3cyl. kubota motor. motor model is722e.Maybe kubmech or some other one could give a diagnosis on this problem
Charging system problem, I think!
- Thread starter hoghead
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skent
Platinum Member
14.5 sounds OK for a 12 volt battery. Check voltage after you are done using tractor (like after an hour or two). As long as it's under 14.75 it should be OK.
Bird
Epic Contributor
Hoghead, I'm not familiar with that machine, but it does sound to me like you've figured out the problem; overcharging them. Sounds like you need a regulator to cut back when the battery is fully charged.
jinman
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Hoghead, I agree with you and Bird that the charging system is not regulating the voltage down and you are constantly trying to charge the battery. 3.5 amps is high in my estimation. If you have a clamp-on ammeter, check your car/truck after it has run for awhile and see what kind of current you draw there just for comparison. The fact that you keep boiling cells dry is also a clue. Do you know whether the regulator is internal to the alternator or external? Many times alternator shops or autoparts shops can check alternators and regulators; however, the charging system might not be Kubota. Good luck.
Just a couple of thoughts, most regulators read battery state of charge and respond accordingly. The lower the battery state of charge the more current (amp) output to bring it back up. If the regulator is sensing the battery needs to be "pumped up" then it's going to to do it. Up to a point that the charging system is designed to "shut-off". After you initially start the machine (if you had an amp gauge installed) you would see a pretty solid amount of amperage going to the battery to bring it back up, then gradually taper off to whatever the electrical system requires to keep things running. If your showing a constant 3-3.5 amp draw while it's running I'll take a geuss and say your engine has the fuel solenoid that continuously holds the fuel shut-off in the open position (another clue would be it's a mower and that works better with the operator present saftey system) Another draw to the sytem possibly in your machine would be the electric pto clutch. That's worth about 5 amps (keep in mind if it's drawing more than 5 amps that could be another source of the problem the charging system is working overtime to keep up) An electric pto drawing more than 5 amps is usually do to the windings getting overheated and shorting. Some of the other things I've seen cause this problem are; Battery too small for the system, it may start the machine just fine, but may also overcharge. Another problem I've seen is putting grease, anti-sieze or other similiar product on the terminals then putting the cables on. Now I don't mean just coating the outside when the cables are installed, that's not a problem. I mean coating the posts then installing the cables. I'll look at some specs for you tommorow if I get a chance.
jinman
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Kubmech, your raise some very valid points. All those "accessory" drains would pull current from the alternator, but if the physical connection is not on the battery terminal (like most of our cars/trucks are) reading with a current probe right at the battery should only show charging amps. For example, if the accessories are powered from a connection at the starter solenoid, you could read current at the alternator and current at the battery and the difference would be the accessory drain. At least, I think that's how it works. It's very hard to say without seeing the circuit and your experience may indicate that I may be missing something.
No Jim you're not missing anything, I missed the part in his original post about where he was checking current./w3tcompact/icons/blush.gif Then off I go on a tangent as if he had an amp gauge in the system. Kind of got off track a little. Alot of the older mowers had them in the dash, made troubleshooting a little easier (that is if the darn amp gauge was'nt broke). As far as how it's wired. More than likely the "main power" lead is hooked where the POS battery cable bolts to the starter.
Looked up some specs today, now this does'nt necessarily mean that's what Woods is using, but I bet it's close. I'm counting on the fact that this engine most likely has a "dynamo". That's the little alternator with two ac leads coming out of it (same color). Which requires a seperate voltage regulator (most likely buried so deep under the dash you can't see it, much less get at the wires with a meter). To test the Dynamo, set your meter for ac volts. Disconnect the two leads from the harness and hook both leads up to the wires. Start the engine and run it at full throtle. You should see 20 acv minimum output, most likely it'll
read about 36-45 acv. I doubt you'll find a problem there. Those little dynamos rarely fail. But part of troubleshooting is finding what is'nt the problem, and that's an easy enough check.
Now, normal output from the regulator is 14-15 amps/14-15 volts @ full throttle.
Battery specs for this system are: 45 amp/hour x 6 = 270 cold cranking amps.
So give the battery a good charge, with a battery charger. Start the machine and let it run about 10 minutes at full throttle. Check intitial current output, then compare initial with
what it's putting out after running 10 minutes and see if there is a difference. If it's the same it's a good bet the regulator is at fault.
Looked up some specs today, now this does'nt necessarily mean that's what Woods is using, but I bet it's close. I'm counting on the fact that this engine most likely has a "dynamo". That's the little alternator with two ac leads coming out of it (same color). Which requires a seperate voltage regulator (most likely buried so deep under the dash you can't see it, much less get at the wires with a meter). To test the Dynamo, set your meter for ac volts. Disconnect the two leads from the harness and hook both leads up to the wires. Start the engine and run it at full throtle. You should see 20 acv minimum output, most likely it'll
read about 36-45 acv. I doubt you'll find a problem there. Those little dynamos rarely fail. But part of troubleshooting is finding what is'nt the problem, and that's an easy enough check.
Now, normal output from the regulator is 14-15 amps/14-15 volts @ full throttle.
Battery specs for this system are: 45 amp/hour x 6 = 270 cold cranking amps.
So give the battery a good charge, with a battery charger. Start the machine and let it run about 10 minutes at full throttle. Check intitial current output, then compare initial with
what it's putting out after running 10 minutes and see if there is a difference. If it's the same it's a good bet the regulator is at fault.
Keoke
Gold Member
Hoghead, an amp gauge at the battery would read current going to battery NOT current coming out of alternator. Current coming out of alternator goes first to your loads and what is left, if any, goes to battery to replace starter draw. If your amp meter is correct you are taking care of your loads and pumping 3.5 amps to battery. Word of caution, inductive amp meters are far from accurate. Better to put a series meter in the circuit for accurate measurement. If amps going to battery is to high (3.5 amps constant) put a coil of 14 gauge wire on the DC output lead in series from alt or external rectifier/regulator to lower amps to battery. Make sure coil is downstream from load take off point. You don't want resistance between loads and alt. A couple of amps constant should be enough here. Vary the length (turns) of the coil to get the amps to battery you want. This may be a cheaper way to get the current going to battery under control.
The Europeans and Japanese call alternators dynamo's, the AC can be internal or external rectified to DC. Most small dynamo's use external rectifiers.
george, keoke
The Europeans and Japanese call alternators dynamo's, the AC can be internal or external rectified to DC. Most small dynamo's use external rectifiers.
george, keoke
"I'll take a geuss and say your engine has the fuel solenoid that continuously holds the fuel shut-off in the open position" !!!
Yes kubmech it does but i didn't think that would draw that much! and yes it does have an external voltage reg and beilieve it or not ,I can get a meter to the output wire on it.That is were I tested voltage at.Voltage at full throttle=14.5volts..Voltage at idle =13.5 volts..I guess i am going to have to put am ammeter "in line"right at the voltage reg output.
I did charge the battery before i did all the tests, and I did check the voltage at the regulator output, and the voltage never drops at the regulator output wire.My friend has the same mower and has the same problem.Dealer says he has not had any other like this but would call Woods to inquire.I would just go ahead and swap the reg, but it is like Kubmech says, diagnosing is what really make a mechanic..My dad was a mechanic for 40 years before his passing and he always taught me not to be a "parts changer" but rather to diagnose the problem.. I owe all the knowlege of mechanics to him because he always made me figure out the problem, before he would come and help!!
Yes kubmech it does but i didn't think that would draw that much! and yes it does have an external voltage reg and beilieve it or not ,I can get a meter to the output wire on it.That is were I tested voltage at.Voltage at full throttle=14.5volts..Voltage at idle =13.5 volts..I guess i am going to have to put am ammeter "in line"right at the voltage reg output.
I did charge the battery before i did all the tests, and I did check the voltage at the regulator output, and the voltage never drops at the regulator output wire.My friend has the same mower and has the same problem.Dealer says he has not had any other like this but would call Woods to inquire.I would just go ahead and swap the reg, but it is like Kubmech says, diagnosing is what really make a mechanic..My dad was a mechanic for 40 years before his passing and he always taught me not to be a "parts changer" but rather to diagnose the problem.. I owe all the knowlege of mechanics to him because he always made me figure out the problem, before he would come and help!!
and also the pto clutch is disengaged when I was running tests so the only draw should have been the fuel solenoid..No lights or other appliances were on and since this motor does not require voltage for ignition, that should be all that is drawing juice!