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

Posted: 09:19pm 16 Jul 2016

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Thanks for help again. Will have a look at the regulator and do more cleaning and check if it is a solid state or spring type. It had done 1384 hrs. in 1979 when the previous owner had bought it, so I doubt that it is a solid state one.

Assuming it is a spring-loaded type, do I gently release the spring tension to reduce the voltage?

I measured the voltage on top of the battery at the +/- poles. Will measure it at the regulator and alternator after cleaning the earth contact.

What am I supposed to check once I switch the light on, is it the voltage at the battery?

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

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oztules

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

Posted: 12:31pm 17 Jul 2016

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Long time since I played with them... but it is simple.... just gently lean on the tension lever and see what changes, and then you will know whether to tension or detension the spring/s.

However.....

Generally, the closed contacts made the max current, and open the least... resistor remains in parallel at all times across the points to both give a small charge current to keep the first make coil alive, and to stop point erosion.... it vibrates at high speed to regulate the current.... so guessing you detension to increase power, and increase tension to relieve power.... make it harder to close the contacts.

Oh, usually two coils, one to make/break the alternator from the system so it does not draw power whilst off, and the other to regulate current.

...........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: 01:20pm 17 Jul 2016

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You are correct, Oztules; I finally found the regulator whilst balancing on the wet tyre, another "black box" was the relay for the indicator. Two coils, one resistor and the other a two-pole relay and at rest one pole is energized. A lever holds the spring, so only a very primitive adjustment is possible via bending of that lever to increase the spring tension, a "detensioning" does not seem to be possible.

As a guess, would the 15.3V be the result of this spring having become a bit tired with age like myself?

That battery must be more than seven years old as I never changed it and always managed to get away with charging this 143Ah battery with a 10A (not C/10!) charger overnight, so I better spend some money and then see how the system behaves with a new battery, which I definitely then do not want to charge with 15.3V for too long and cook. If there is still a problem with 15.3V, I will have to increase the spring tension via bending.

That battery is so heavy, that I will have to slide it out via ramps into the car and slide the new one in.

Another question: Such large tractor batteries do not sell very often and how can I check if that battery has not been in the shop for too long and sulphated as a consequence? Batteries do not seem to have a "Year of manufacture" stamp. Should I take a volt meter along or do I have to take pot luck?

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
Location: Australia
Posts: 1686

Posted: 04:43pm 17 Jul 2016

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Yes, more than likely the spring tension has relaxed a tiny bit. You will find it is very touchy as to how much is too much etc... take it gingerly.

Depending on how long the battery has been standing will give you the self discharge rates.... I don't know a lot about this..

There is a voltage below which sulphation does not really take hold.... thats 1.225.. so if the shelf battery is above this, then sulphation has not begun ( 12.4v open circuit sitting for 24hrs and above should be ok)... thats the theory... but see below.....

Battery technology is not well understood after 100 years.. even by those making them. It is far more complex than the redox reaction often quoted... and there appears to be more stages in between that we don't see... (yes that happens in the physics world, look for planck time and the effects inside that period... anything goes)

The proof we don't really know is that no-one has been able to successfully desulphate any battery using witches brews, pulse charging and any other method .... even changing electrolyte to distilled water only works sometimes ( distilled water dissolves sulphate far better than electroylyte.... and as the sulphate dissolves, we get acid again... neat, but why does it not work all the time, only under certain circumstances we cant predict... like all the cures, works on some sometimes... why?????)

No matter what the boffins say, they don't really know all about this cycle, or we could do it heaps better.

.............oztulesEdited by oztules 2016-07-19

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

yahoo2

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

Posted: 06:58pm 17 Jul 2016

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So, here is the thing

A standard 4wd battery N70ZZ is 670 cold cranking amps and 143 minutes reserve capacity(RC) capacity at 20kg.

A N86 or N87 (terminals are reversed on the N87) is 750 CCA and 175 minutes RC, its 39mm longer and slightly heavier.

reserve capacity is calculated at a load of 25 amps down to 10.5 volts under load.
if you do the numbers a N86 is pumping out a total of 75 Ah over 3 hours.

Just had a phone call from a mate that works on old tractors. He agrees with me that a N70ZZ or a N86 sized battery will be fine, you just have to take note of where the cables will reach and what side the terminal posts are. And make a note of how tall the old battery is and how it is clamped in so you can figure out how to secure a smaller battery.

The other thing he said is he thinks the front clip/grill on those fiats is easy to remove and the big battery could slide out the front. That would save all the struggling and lifting and twisting to get the monster out.

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

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

Posted: 08:19pm 17 Jul 2016

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Thanks Oztules and Yahoo2. My old and rusting Series III Landrover Diesel uses N70ZZ like batteries, but the battery on this tractor is much larger and heavier. I can still lift a N70ZZ, but the tractor one must be slid out the front as your mate is suggesting.

Thanks for help.

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: 10:43pm 17 Jul 2016

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what I was going to say before I lost my train of thought is that back in the 70's the Cold Cranking Amps of most batteries was lower and some of these tractors are designed for ice and snow.
My old 4WD John Deere used to have 2 massive 6 volt batteries in it, I swapped them for one 12 volt N86 around 30 years ago and it has been fine.

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

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

Posted: 12:38pm 18 Jul 2016

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You are right once again yahoo2, the little pamphlet that came with it suggests covering the front of the radiator in winter to allow the engine to warm up more easily. Being an Italian-built tractor, the battery is massive to allow starting in winter. I will check battery prices and see what I can afford.

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

Winston Churchill

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