(800) 853-2651
SHOP NOW

speaking of batteries

G

gotmyfarm!

Member
That was a good question and replies about battery theory. I read it after I got home today with the new 12V battery for the conversion I'll be doing this week on the Farmall M from 6V. My question is, did I get an acceptable battery? I had no idea which one to get. I was at Advance Auto, and I think it was Carquest brand they had? They have good better best, kind of choices. I got the middle quality with the middle 2 yr warranty. So the numbers is what I didn't know about. 6V had higher numbers all around than the 12V, I found out after I got home. 6V had 650 cold crank, and the new 12V only has 575. Is that enough? 6V had 7XX at 32* and 12V has 6XX. Can't remember exact numbers there to the tens. And the 6 had 181 reserve and the 12 only has 80!! Should I get a different 12V battery? Is it too wimpy?
 
It will be fine.

In fact, a lower cranking amp battery can be an advantage, maybe it won't slam the starter so hard.

That small, low compression engine will not need a high capacity battery, especially using a 6v stater. It will spin like crazy even with the lowest cranking capacity battery. You get into the need for high amp batteries with diesels, large high compression engines, and high demand electrical accessories.

I doubt there is any difference in the 1 or 2 or 3 year battery, mostly you are just buying warranty.
 
I think George uses a lawn tractor battery in his Farmall C,and it works fine. If I ever convert ours to 12 V that's what I
will use. My motorcycle has 3 times the horsepower of a Farmall C and starts right up with a battery 1/3 the size.
 
As I understand it by theory only (where's John T)volts X amps = watts and 746 watts = 1 horsepower so 650 X 6 = 3900 watts divided by 746 = 5.23 horsepower. 575 X 12 =
6900 watts divided by 746 = 9.25 horsepower in theory only. Your 12 volt battery should spin that engine over very easily.
 
You are right. I use a used lawn mower battery that has difficulty starting some of my mowers.

Problem with using too large of a battery on a 6 to 12v conversion is the bigger the battery the harder the starter will slam the flywheel and you will have a greater chance of shearing off the starter drive or chipping teeth off on starter ring. Some will say get a heavy duty starter drive. I say a heavy duty starter drive will mean you will have a good chance of splitting your tractor and replacing starter ring.

Try using an old 12v battery first then working up if you have too. Don't think of battery life, think of starter drive life.
 
Old 'rule of thumb' was, for a V-8, Cubic Inch Displacement should match the CCA's. For a six or four, CCA's should be double the CID. (from my days of working at Western Auto-mid 60's)
 
I do not agree with a few of the fellows about higher amperage "slamming" the starter against the flywheel. The voltage is what starts the starter to spin and engage the flywheel.
The starter will spin using the voltage supplied, higher the voltage the faster the motor spins. The bendix gear is thrust into the ring gear by the spin of the starter motor. It does not draw (any appreciable) amperage until the bendix is already engaged and begins to feel resistance from the stationary tractor engine.
A six volt battery will engage the bendix at half the speed as a 12 volt battery on a given starter. Current is drawn by workload applied to the starter motor.
 
Good info, guys. I'm going to take apart the starter and see its condition. This new to me M has been a bad or no start tractor. Starter might be in bad shape but look at these wires! More tape and corroded exposed wire than anything! New wires should be here tomorrow.
mvphoto41433.jpg
 
A smaller battery will do nothing to stop
the selenoid from slamming. A smaller
battery WILL decrease the torque of the
starter If the voltage drops more. If you
want to decrease the selenoid from slamming
you could put a resistor in series, start
with a resistor of about 3 ohms. A coil resistor might have enough wattage. If it
still slams add another and another till it
stops engaging and then take one off. Then
let us know how much resistance is perfect.
The job of the selenoid is twofold. To
engage the starter drive and switch the
battery voltage to the starter. The lower
voltage on the selenoid will not effect the
voltage to the starter motor itself. If I
was an engineer I would have designed a
selenoid that would apply voltage to the
starter AFTER the gears were engaged.
 
I was just thinking. Some starters do not use a selenoid to engage the starter. If that's the case, disregard everything that I said. I wish they had a way to edit posts.
 
If the armature has been dragging on the
field coils; that will make the starter not
work. You can drive out the bushing at the
end of the starter and turn it 180 degrees.
The bushing only wears on one side. You can
buy a bushing driver set from harbour
freight for not much money. Of course it's
not very good steel but it will work. If
the brushes are less than1/2 inch you
should change those at the same time. It
only takes a few minutes to do. Some
bushings absorb oil. Maybe put it in a pan
of oil and heat it up. Your starter might
last another10 years! Just don't grind on
it too long and get it hot. If you have a
manual, it will give you some other checks
to make.
 
I don't think your rule of thumb accounts for applying 12v to a 6v starter.

What's the cubic inches of a Farmall C? I can get buy using a 4 year old lawn mower battery that lucky to measure 150 ccAa on my conductivity meter. Lucky for the battery to start a 20 hp lawn mower.
 
I did something like that once, on a 46 Dodge truck. I would engage the starter with the 6 v system, then I had a 12 volt battery with a separate solenoid, and separate starter button. Worked good!
 
The starter is apart. The brushes are overall length 5/8" or a bit less. The copper twisted wires by them, two of them look ratty, is that ok? The longer wire in a black covering in there has a break in the covering exposing the wire, could I put a small piece of electric tape on it? How do these teeth look? There is a lot of play in the piece that moves in a spiral direction and the whole assembly has extra room lengthwise, so I am wondering if that spring isn't holding things firm like it should be. Is it common for the spring to need to be replaced? Then at the other end, all those copper(?) wires are coated in a dry grease looking substance, is that ok? Pictures below.
 
"You can drive out the bushing at the
end of the starter and turn it 180 degrees."

That idea really needs to win the "frugality award". (Or SOMETHING.)

"If I was an engineer I would have designed a selenoid that would apply voltage to the starter AFTER the gears were engaged."

NO need to "reinvent the wheel", that's EXACTLY how most "solenoid shifted" starters (which have been common since the mid '50's) are designed to work.

It's the OLD-style starters with an "inertial drive" that rev up, then slam the starter pinion into the ring gear teeth that are rough on things.
 
You must log in or register to reply here.

Similar threads

F
Ford 600 Tractor Electrical
Replies
7
Views
686
FordFarm600
F
B
Batteries
Replies
2
Views
506
Blackhole49
Blackhole49
Factotum
6v headlight bulbs
Replies
17
Views
4K
Tim PloughNman Daley RIP
T
R
Alternator Confusion, Positive Ground
2
Replies
29
Views
1K
used red MN
U
3
Interstate batteries
2
Replies
33
Views
776
DoubleO7
DoubleO7
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top