Battery Question

[DrPhil]

I've got a '71 Ford 4000 tractor. It won't start. I figured the battery was bad (It's 6 years old)

But when I checked the battery with a meter it showed good with 12.6 volts.

Maybe I'm just stupid, but....can a battery be fully charged but not have the amps to start the engine?

 

[PILOON]

Just guessing here.
Being a '71 have you checked grounds and the rest of the grounding path?
Not just battery terminals.
Sometimes they ground to a subframe and rely on the engine block being bolted to the subframe for ground return.
Ground return even includes the bolts that mount the starter.
Also you really need a load on battery to check starting capability.
All ground paths need to be shiny 'metal to metal' to perfform.

Good luck.


.

 

[EddieWalker]

Yes.

Most parts stores will test your battery for free and tell you if it needs replacing. The testers that they use measure more then just the voltage, but I forget exactly what they test other then it's more then my volt meter does.

Cold weather will also kill a battery that was working OK, but might have been near the end of it's life.

What is happening with your tractor? does it crank at all? Does anything happen?

Eddie

 

[LBrown59]

I've got a '71 Ford 4000 tractor. It won't start. I figured the battery was bad (It's 6 years old)

But when I checked the battery with a meter it showed good with 12.6 volts.

Maybe I'm just stupid, but....can a battery be fully charged but not have the amps to start the engine?

....can a battery be fully but not have the amps to start the engine or not?

 

[ampsucker]

absolutely. it is the difference between open circuit voltage and load voltage.

to illustrate. you can hook flash light batteries end to end (in series), say C cells, together. the voltage will be 1.5 times 8, or 12 volts. think it will turn over your tractor engine? no way. you need to be able to deliver the current the starter needs to turn over at it's rated voltage. make the cells cold and it's even worse.

i would check all your connections and cables to make sure they are good, clean metal and not corroded in any way. then, if you have one of the newer type electric chargers with a desulfate or equilibrate setting, try running that cycle on the battery. first, remove the battery from the tractor. check the water in the cells of the battery and top of with distilled water if any low. then run a desulfate cycle. it will take 12 - 24 hours. now the battery is in the best shape it can be for its age.

try it to see if it works or load test it if you have a load tester. your local auto or farm supply shop could also load test it for you.

chances are, it's toast after six years. thats about the typical life of a lead acid battery in storage. the inner plates start to internally short out and current draw is significantlyl reduced. worst thing on a lead acid battery is storage in a partially charged condition.

the best way to keep your new battery from going downhill is to keep it top charged with either a $5 harbor freight trickle charger or a small solar charger (about $25).

good luck.

amp

 

[Ray_Fort_White]

When you buy a new battery make sure you get an AGM (absorbed glass mat) battery. It has sort of a fiberglass sponge between the plates. It greatly extends the life of the battery. Gunk shed by the plates doesn't accumulate in the bottom of the battery; it reduces the effect of vibration and retards crystal 'finger' growth from the plates.

Spend a few bucks more than you would for a trickle charger and get a "battery tender" or other brand of maintainer. The newer ones are 3 stage with a brain. A cheap trickle charger will toast the battery over a long period unless it is voltage and current regulated. I once tried placing a trickle charger on a timer but that was even worse. It had leakage when off.

I'm amazed that we have lead acid batteries at work (phone company) that are 30 years old. They are always float charged and don't get too hot or too cold.

 

[jinman]

I've got a '71 Ford 4000 tractor. It won't start. I figured the battery was bad (It's 6 years old)

But when I checked the battery with a meter it showed good with 12.6 volts.

Maybe I'm just stupid, but....can a battery be fully charged but not have the amps to start the engine?

I have never seen a bad battery that has sat for several days or even overnight and have a 12.6 vdc reading. Weak batteries can take a "surface charge" and show 12.6 vdc right after engine shutdown, but if that battery has sat overnight and shows 12.6, I would say it is most likely a bad or dirty connection, especially if you are in a humid area or right after a rain storm. Battery cables can have very thin corrosion and not be making electrical contact. I would remove the battery terminals and then use jumper cables to connect the battery to the outside of the terminals by clipping onto them. If you can monitor the battery voltage while starting, that will also tell you what the battery is doing. You do have a very old battery, but my bet is dirty or loose terminals.

 

[Soundguy]

I've got a '71 Ford 4000 tractor. It won't start. I figured the battery was bad (It's 6 years old)

But when I checked the battery with a meter it showed good with 12.6 volts.

Maybe I'm just stupid, but....can a battery be fully charged but not have the amps to start the engine?

Yes an no.

Check the battery with a specific gravity tester.. might have a weak cell.

Make a voltage test on it while cranking.. I bet it drops to near 0 under load.

This could be a bad cell or bad connections and bad ground. connections at the terminal ends and the terminals and the ground need to be checked, cleaned.. and preferably.. greased to prevent more corrosion. If you havn't done so alrady.. charge the battery.. and if not maint free.. check the fluid.

Is this the big 4DLT job?

soundguy

 

[john_bud]

Check the cables for looseness and corrosion. Fix any found. Freshen up the ground connection to the frame and if you have "extra time" add a ground cable from the frame ground to a bolt on the starter mount.

In cold weather, engines are hard to start as they spin slower. A thinner oil like 5w40 or 5w30 may help.

Heating the intake manifold with a hair drier or heat gun works too.

jb

 

[DrPhil]

Wow...Thanks for all the INFO! I learned a whole lot this morning.

Got another question. My battery was hooked up as a postive ground. That confused me so I researched a little bit and found out that Ford's used to be postive grounded but changed to negative ground in the late 60's.

My '71 tractor has always run fine as a postive ground...but should it be hooked up as a negative ground? What's involved in changing to a neg. ground...can you just swap the connectors?

 

[c23380]

One quick way to tell what you have is hooking you meter to your battery clamps and turn on your lights. Usually a bad battery will begin to drop voltage and fal below 12.5 volts within a minute or so.A good battery will remain 12.5 to 13 volt for 5 to 10 minutes befor dropping. The specific gravity is a sure way to test, as soundguy suggest, but if you do not have a tester The meter trick will lead you in the right direction, Mike

 

[Soundguy]

Drphil.

if the tractor still has a generator, and does NOT have an alternator, then yeah.. you can swap the battery to negative ground, and then repolarize the genny by jumpering bat to field for a second.

soundguy

 

[ampsucker]

the battery absolutely does not care which pole is ground. you can design the system either way. in a DC system, the ground is just using the metal in the frame as the conductor for simplifying the wiring.

why change it?

if you do want to change it, in addition to changing the the connections on the charging system, don't you have to change the polarity of your starter motor so it doesn't crank the engine backwards? DC motors are directional aren't they? and also your meters if you have any on the tractor? ammeter and volt meter would try to show negative if not rewired.

i would just leave it the way it is.

amp

 

[Soundguy]

Amp...

Permanent field dc motors spin backwards when you reverse polarity..

fortunately that ford starter we are talking about has a non permanent field 'coil' ! polarity swaps on it just the same as the armature.. thus the same rotational direction is achieved positive or negative ground.


Also, when OEM,.. no amp gauge or voltage gauge oem on that machine.. just a charge indicator lamp... lamp on = discharge, lamp off=charge.. was designed to work on the lucas regulator.. but is EASILLY made to work on a gm 3-wire alternator so that the lamp functions the same way.

the machine was designed and rolled out of the factory as negative ground.. best to run it THAT way. less problems with jumps and chargers from non observant individuals down the road.

soundguy

 

[ampsucker]

thanks for the education! i always like learning something new....

;-)

amp

 

[ArTrvlr]

When you buy a new battery make sure you get an AGM (absorbed glass mat) battery.

Spend a few bucks more than you would for a trickle charger and get a "battery tender" or other brand of maintainer. The newer ones are 3 stage with a brain. A cheap trickle charger will toast the battery over a long period unless it is voltage and current regulated. I once tried placing a trickle charger on a timer but that was even worse. It had leakage when off.

I'm amazed that we have lead acid batteries at work (phone company) that are 30 years old. They are always float charged and don't get too hot or too cold.

I've got a '71 Ford 4000 tractor. It won't start. I figured the battery was bad (It's 6 years old)

But when I checked the battery with a meter it showed good with 12.6 volts.

Maybe I'm just stupid, but....can a battery be fully charged but not have the amps to start the engine?

I agree that the AGM (Optima, Odyssey, etc.) batteries are worth the extra cost. Just the lack of acid leakage and resulting corrosion is worth a lot to me.

I have had good luck so far with the Harbor Freight battery maintainers. I believe they are more than a trickle charger, at least they claim to stop charging when the battery is fully charged, and they claim to charge again when voltage drops. I say "claim" because HF makes some questionable claims. But, as with any HF tool, the only way to know is to try it. I have three old cars that I drive very infrequently, always leaving a HF charger on each one while it is parked. Knock on wood, but in about three years, (all with batteries two to three years old when I started using the HF chargers) I have never had a dead battery, And never had one overcharged, at least not to the point of loosing water. This is what I use: Harbor Freight Tools - Quality Tools at the Lowest Prices
It may not have as sophisticated electronics as a Battery Tenda brand, but it sure costs a lot less. I got some of mine on sale for a couple of bucks.

One other thing those phone company batteries don't have to contend with that auto/truck/Ag batteries do, is vibration.

DrPhil, did you get the tractor started???? Was it the battery or something else? Inquiring minds want to know!