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domwild
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Joined: 16/12/2005
Location: Australia
Posts: 873

Posted: 11:11pm 16 May 2016

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Hi,

My Fiat 650 (65HP) tractor charges the battery at 12.7V while idling.

Q1.: Is this correct or should it charge at a higher voltage?

The battery is supposed to be a 143 Amphr battery but we seem to be buying batteries using CCAs (Cold Cranking Amps). The experts (ex-has been, spurt-drip under pressure) in the shops claim there is no ready made conversion possible and I do not wish to buy, what is surely going to be an old remnant of a sulphated battery simply on size alone.

Q2.: How many CCAs might that one be??

Thanks.

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

gpalterpower

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Joined: 19/07/2009
Location: Australia
Posts: 175

Posted: 11:24pm 16 May 2016

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Hi Domwild,

What size Alternator does the tractor have and what year model is it? A lot of earlier tractors have that problem, depending on year of manafacture. If you dont have air conditioning then that charging level is probably OK, as long as the battery voltage climbs to 14.4v with a few more RPM. Battery size for that HP tractor would be either a 'N70Z' or an '86'. Marcus

if it aint broke dont fix it!!

domwild
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Posted: 01:30pm 17 May 2016

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Thanks for reply. Model would be late 1970s, manual tells me max. output of alternator to be 595W at 2200 RPM, no airconditioning.

After having bought a new batt. I will simply up the revs and check again as I am hoping to get a bulk charging rate higher than 13V to blast the sulphate off the plates as the tractor stands idle for four to five weeks at a time. Might need new brushes?

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

yahoo2

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Joined: 05/04/2011
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Posted: 02:49pm 17 May 2016

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it is not charging.

the regulator should be floating the battery close to 13.8 volts when it is fully charged and running up to 14.4 volts under load.

I have got a feeling that the brushes and controller are in one module on those fiats. it pays to check that the power wire onto the module is getting power when the key is on and the earth (probably via one of the bolts) is not crusty before you go to town on the brushes.

I'm confused, no wait... maybe I'm not...

domwild
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Posts: 873

Posted: 01:02pm 21 May 2016

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Thanks yahoo2. That is more likely! Will check next time I am in the bush. Looks like the 12.7 measured is the battery voltage after charging (idling) and not being charged itself. Perhaps I can even save myself buying a new battery once I find the fault.

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

gpalterpower

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Joined: 19/07/2009
Location: Australia
Posts: 175

Posted: 11:58pm 23 May 2016

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So your alternator is 40 -45 Amp. 7 amps of that would be going in to keeping your battery topped up. If your alternator and reg are working ok, then the MAXIMUM voltage would be 14.4. Never designed to go any higher. A 70's model may have an external reg,(if you can send me a pic, I can confirm for you) and if a bobbin type, can be adjusted if charging too low! Be careful if you are attempting to adjust as they are touchy and voltage can run away....possibly can cook your alt. Seeing it doesn't have air con, the biggest drain would be headlamps or work lamps when running. So really the main problem could be that the alt isn't been turned fast enough at idle. A little trick you could try if you are mechanically handy is to fit a slightly smaller pulley on the alt. You could also try fitting another type of alt. A Bosch 80A would definitely cure the problem.
Marcus

if it aint broke dont fix it!!

Downwind

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Joined: 09/09/2009
Location: Australia
Posts: 2333

Posted: 01:54am 24 May 2016

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Do you disconnect a battery terminal between the 4-5 weeks idle use time.
I think you will find a far better battery storage life if you do.

Often the smallest current drain can do the biggest damage over long cycle times.
Tractors are always good to have a flat battery when you need them, in industry we always found battery isolation switches helped, but disconnecting the battery terminal is cheaper for the same result.

Sometimes it just works

gpalterpower

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Joined: 19/07/2009
Location: Australia
Posts: 175

Posted: 02:16am 24 May 2016

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Hi Domwild,
If the tractor is going to be left idle for that long then definitely disconnect the battery. As you know, its not good for batteries sitting around for that length of time without a charge, so, maybe a solar trickle charger may be the answer. Alternatively , you could remove the battery and take it home with you and do the same.

if it aint broke dont fix it!!

yahoo2

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Posted: 03:49am 24 May 2016

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I'm confused, no wait... maybe I'm not...

domwild
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Joined: 16/12/2005
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Posts: 873

Posted: 12:31pm 24 May 2016

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Thanks for the many answers. Find it hard to understand that there is a drain on the battery when the master switch is off, however, I know batteries self discharge. Perhaps that can be explained to me so I disconnect.

Will follow the schematic to see which cables, as suggested, may be corroded at the terminals. Current has to go to the windings once the master is on.

Battery is too heavy to lift out easily as wife is also 75! In fact, the previous owner overfilled the oil bath air cleaner, which meant the lower part of the radiator got covered in oil and blocked with dust leading to overheating. Found then that I had to use ramps to slide the battery out to work on the radiator. If I ever have to change the battery I will have to slide the battery from van to tractor on ramps.

Have seen a black box, which may be the regulator, but will check the schematic.

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

domwild
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Posted: 11:55pm 14 Jul 2016

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Hi again,

This tractor has an external voltage regulator and I also have a circuit diagram. With the switch to ON, I checked if the coils get excited from the regulator and it measures 11.8V after scratching off layers of oxide, with the battery at idle and (after standing for some time) reading 12.3V.

Does this mean the regulator works as there is current going into the coils?

The forum established that the alternator does not charge as I am only reading 12.7 while running, which is the battery voltage after charging but not the alternator's voltage, which should be about 14.7.

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

Madness

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Joined: 08/10/2011
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Posts: 2498

Posted: 12:32am 15 Jul 2016

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Try giving it few more revs than idle, I don't think you can expect full output unless the engine is at operating speed.

There are only 10 types of people in the world: those who understand binary, and those who don't.

oztules

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Joined: 26/07/2007
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Posts: 1686

Posted: 01:42am 15 Jul 2016

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what are you terming as coils?

If you have 12v going to the slip rings to the rotor coil, you will have full magnetising, and should get something even at idle... fast idle shoud be enough to prove or disprove whats happening..

If your confident that 12v or so goes into the rotor coils, then you have blown diodes.

Normally external regulators have grounded one brush and excite the positive brush.... so should be able to see 2 ohms or more looking into the rotor through the brushes inputs ( GND and probably one labelled field)

I cover this fairly well in depth here:
http://www.anotherpower.com/board/index.php/topic,492.0.html

It should give you a feel for what to see is inside of the little rotters.

Actually just built a little 6.5hp one of those for a 48v system using a standard 12v alternator.

.........oztulesEdited by oztules 2016-07-16

Village idiot...or... just another hack out of his depth

domwild
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Posts: 873

Posted: 01:50pm 15 Jul 2016

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Thanks, Oztules. Was ignorant until you told me which side gets magnetized, the rotating coil or the static coil. It definitely has an external regulator with a fuse hanging off it. There was a lot of oxidisation at the fuse, which I scratched off.

Thanks for link, will read. Seeing that you have a black belt in electrickery, what sort of a chance do I have to get an external regulator for this old Fiat tractor and if not, can I use any other regulator I can lay my hands on?

The small manual tells me that if the tractor is running off an external battery to pull the connection to the alternator off via a spade lug. This spade lug was pulled, the master switch was set to ON, the no charge light lit and there to earth I measured 11.8V. I take it that that spade lug and judging by the colour of the wire as per schematic is the lead from the regulator. Will check for the two Ohms.

Thanks once again.

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

oztules

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Joined: 26/07/2007
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Posted: 02:05pm 15 Jul 2016

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There is nothing cunning or mysterious in alternators.

Read the description I did, and provided you have a rotor and stator, bearings and housing, we can make the rest.... for a few dollars only.

Must go fix a 20 footer container fridge up north now... gotta go.

.............oztules

Village idiot...or... just another hack out of his depth

domwild
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Joined: 16/12/2005
Location: Australia
Posts: 873

Posted: 08:46pm 15 Jul 2016

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Thanks for the beaut write up in Otherpower. May have to ask for your help again if I can't fix the diodes. An assuming the regulator works.

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

yahoo2

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Joined: 05/04/2011
Location: Australia
Posts: 1166

Posted: 09:53pm 15 Jul 2016

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Make sure you check that the brushes are getting good connections before you get to far down the rabbit hole.

if they have had oil on them they will not work, I use acetone (nail gun cleaner) in a pressure pack can to loosen the gunge.

I'm confused, no wait... maybe I'm not...

domwild
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Joined: 16/12/2005
Location: Australia
Posts: 873

Posted: 02:06pm 16 Jul 2016

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Thanks yahoo2. Acetone is also in the nail polish remover for those without guns! Now I think I may have solved one problem to find another:

Cleaned the oxide off the fuse hanging off the external regulator, managed to start the tractor and after warming up measured the voltage repeatedly and at 800 RPM it had crept up to 13.4V.

Later increased the RPM to 1600 and found the voltage had crept up to 15.32V! Must assume the brushes,diodes and the alternator are OK but the regulator has gone West? The battery had not been charged for nine weeks and I am happy that I just managed to start the tractor again. Had I not forgotten the extension lead, then I would obviously charged the battery BEFORE starting.

Must I assume the regulator is dead or would a nearly "empty" battery lead to serious over voltage, as 14.7V should be the max.?

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

yahoo2

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Posted: 03:25pm 16 Jul 2016

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I dont have a nail gun, but I use the spray for a lot of things.

Good! that is progress. the voltage will depend on where you are measuring it and the quality of the wire and connections between those points.

So it might be 15.3 at the alternator and 14.8 or much less at the external regulator. the regulator can only adjust the voltage that it can see at its own terminal. I am doubtful that if you measured the voltage directly on top of the positive battery terminal (not the cable clamp) it would be that high.

it does not necessarily mean the regulator is shot it may just have poor connections on the positive side between it and the alternator or even the negative connections on the regulator might be not making good contact and the earth voltage is not at 0 volts and is floating up.

If you are measuring 15.3 everywhere then its a problem and the regulator is out of adjustment or stuffed or not seeing a good earth.

What happens if you switch the lights on?

I'm confused, no wait... maybe I'm not...

oztules

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Joined: 26/07/2007
Location: Australia
Posts: 1686

Posted: 04:19pm 16 Jul 2016

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Everything Yahoo said..... and is this a solid state regulator or a two or three coil type.

If the coil type, then you may well get it to the correct voltage by changing the tension on the return springs ( it will be obvious when you pull the cover off)

They are fairly flimsy, so be careful, but they change the charge characteristics completly.

If you use the tractor for long periods, then 15.3 is high, if you use it for short durations, I would not be over concerned, just check the water occasionally.

But particularly check as Yahoo mentioned, the change in behavior to change in load.

If it regulates, but at the wrong voltage, then spring tension will fix it, if it is oblivious to load change and just runs wild, then it has a problem with crap connection or failure of the resistors on the back of the reg.

If it is solid state, then a new one or build one is in order.
At least the alt works

..........oztules

Village idiot...or... just another hack out of his depth

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