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?