445 Battery Light On

[BBO]

The battery is 5-years old & I have been expecting to replace it, but...

Yesterday the battery light came on.
So with it running I checked the battery voltage, 14.37 vdc.

I shut it, off and the battery cranks the mower as normal; battery light still on when running.

With the mower off the battery voltage seems even high, at 12.90 vdc.

Can it be overcharging?

 

[Richard001]

BBO,

I don't think that the battery light on the dash is smart enough to know if the battery is being overcharged.

You said:

With the mower off the battery voltage seems even high, at 12.90 vdc.

There is always a little residual extra charge on a battery after it has been charged. Let it sit for and hour, then measure it again and let us know what you get then.

There was a guy who posted here recently that he felt his battery was being overcharged and he did find a problem with the connector at the regulator. Check the connector and the contacts. Scrape the contacts to make them shinny.

Here is the operation description of the charge circuit:


And here is the Schematic:


I have a PDF of the 445 service manual, but it's huge, 67MB.

Richard

 

[Garrett Wiggins]

It could also be a short in the wiring causeing it to back feed and cause the light to come on too right?

 

[BBO]

BBO,

I don't think that the battery light on the dash is smart enough to know if the battery is being overcharged.

You said:

There is always a little residual extra charge on a battery after it has been charged. Let it sit for and hour, then measure it again and let us know what you get then.

Richard

Well after sitting 2 days the battery voltage is still 12.37vdc and it still cranks fine.
And now (at least cold) the battery light is not on when running!

I will update this the next time I mow...

 

[Richard001]

Just for your info:

LEAD-ACID BATTERY INFO

A battery’s condition can be monitored by checking the electrolyte’s specific gravity with an inexpensive D-I-Y battery hydrometer to determine the percentage of sulphuric acid it contains.

A fully charged cell at 80 degrees F would show a specific gravity of 1.265. If all six cells are fully charged, an accurate digital voltmeter reading of battery voltage would show 12.68 volts.

Specific gravity for a 50 percent discharged cell would drop to 1.19 and battery voltage would fall to 12.24.

When specific gravity reaches 1.12, the cell is fully discharged and battery voltage falls to 11.89 volts, assuming the specific gravity is the same in all six cells.

Because specific gravity is affected by temperature, subtract .004 per 10 degree drop below 80 degrees F.


Richard

 

[BBO]

Just for your info:
LEAD-ACID BATTERY INFO
A battery’s condition can be monitored by checking the electrolyte’s specific gravity with an inexpensive D-I-Y battery hydrometer to determine the percentage of sulphuric acid it contains.
A fully charged cell at 80 degrees F would show a specific gravity of 1.265. If all six cells are fully charged, an accurate digital voltmeter reading of battery voltage would show 12.68 volts.
Specific gravity for a 50 percent discharged cell would drop to 1.19 and battery voltage would fall to 12.24.
When specific gravity reaches 1.12, the cell is fully discharged and battery voltage falls to 11.89 volts, assuming the specific gravity is the same in all six cells.
Because specific gravity is affected by temperature, subtract .004 per 10 degree drop below 80 degrees F.
Richard

I have read that you are supposed to add distilled water to a battery with low fluid level.
I have wondered why you do not add battery acid instead...

It's interesting when you buy a dry battery at a JD dealer, they fill it with acid...
Then they say you can charge it, but it's not totally necessary.
The battery will likely read over 12V and it will work without any time on a charger.
The same is true with a motorcycle battery.
With the acid, the cells start working.

And if you leave the light on in a car, killing the battery, just letting it sit for a time it may recharge itself enough to crank.

 

[BBO]

Update.
I had the battery tested. It is indeed good. (It's a 10 yr old Autozone battery!)
I now have a JD 3-year old battery on it and the symptom is the same.
It cranks fine and the light is not on when it's cold.
But with either battery after mowing about 1 hour the light comes on, and will not go off.
(Even after cranking it hot, the light comes right back on)
With the light on, it's still charging at about 14.4 vdc.

I plan to take the regulator off and look at all the wiring.
But I am wondering if the regulator is putting out too much voltage???

 

[Richard001]

Update.
I had the battery tested. It is indeed good. (It's a 10 yr old Autozone battery!)

Wow that is amazing. A lead/acid battery that lasted over ten years !

I now have a JD 3-year old battery on it and the symptom is the same.
It cranks fine and the light is not on when it's cold.
But with either battery after mowing about 1 hour the light comes on, and will not go off.
(Even after cranking it hot, the light comes right back on)
With the light on, it's still charging at about 14.4 vdc.

I plan to take the regulator off and look at all the wiring.
But I am wondering if the regulator is putting out too much voltage???

BBO - If you are measuring 14.4 V with engine at fast idle, that would be the correct voltage out of the regulator.

I suspect that, even though the output voltage is correct, that the voltage sensing part of the regulator is faulty. Have you removed the regulator connector and checked for good connection of the connector contacts?

Richard

 

[BBO]

Wow that is amazing. A lead/acid battery that lasted over ten years !
BBO - If you are measuring 14.4 V with engine at fast idle, that would be the correct voltage out of the regulator.

I suspect that, even though the output voltage is correct, that the voltage sensing part of the regulator is faulty. Have you removed the regulator connector and checked for good connection of the connector contacts? Richard

I took the VR connector off and cleaned it, but no visible signs at all that this is the problem.
No signs of corrosion or heat damage.
I will mow again later today to see what happens.

 

[Spanner]

And...

:wrench:

 

[BBO]

And...

:wrench:

:drink: Well, the light has not been on since.
All I done was to take the regulator off, pull the connector off and clean everything.
Before & during all this no water was involved, so it was not moisture.
I did clean all the blades on the connector, but nothing looked corroded!
No signs at all of heat problems!

I did clean out a fair amount of dust which is always there.

So I am befuddled as to why the light was coming on.
And for now I am still running the JD battery that I added the acid to.
Remember earlier it would not crank the mower, when I found the level low.

 

[Spanner]

Clean connections and set to go! Good news BBO.
Thanks,
:wrench:

 

[Dave M7040]

This is a post I made to the owner with the identical problem

On many lawn tractor models the wiring is a bit different than you would expect.
Yours is likely the same. The dash light signal is not coming from the charging system itself rather is is just a simple voltage sensor connected to the dash light

For the pto electric clutch, +12 volts is supplied to it all the time the key is ON.

When you use the switch to engage the clutch, you are providing a path to ground so that safety switches etc can easily be in the ground circuit. Also, the relay that shuts down the mower deck when you back up, cuts the ground thus disengaging the electric pto clutch.

The dash display is just a simple low voltage electronic sensor and is stupid.

It has a need for a ground and a power wire. If the overall ground for the many things on the tractor is using a corroded connection to the frame, and the low voltage indicator is likely using the same ground, then when you engage the pto clutch, the grounding of the clutch may be enough to just engage but it is also providing some voltage to the ground for the dash indicator causing it to illuminate.

Check for a green wire attached to the tractor fame or a green wire connected to the negative battery terminal. It will be a light gauge wire.

This cub cadet wiring diagram is not an exact image of what will be where on the tractor. Its purpose is to show the function of various circuits so it does not show the voltage sensor ground and the pto clutch ground being tied together and connect to the frame or negative battery terminal.

If you have a cheap, less than $10 multimeter to measure the battery voltage, you will find it around 14 volts when the engine is running and the pto engaged but the dash light will be on which is why I say it is a stupid device.

Dave M7040

 

[Spanner]

The system Dave is describing/illustrating is peculiar to Cub Cadet (MTD). "Everything-powered, Apply Ground-to-operate."


JD, and most conventional systems use: "Everything-grounded, Apply Power-to-operate."

:wrench:

 

[BBO]

Another update to my original problem, because it's NOT fixed...
When this 1st started on this I found the battery almost dry, & corrosion was all around the battery.
So with another battery I started working on all this.
Remember my 1st thought was that it might be OVER charging??
So last week the charging light finally came back on.
I find this battery with almost all the acid gone again, after only a few weeks.
I think the voltage regulator is simply cooking the battery.
Is this possible? Has anyone had experience with a voltage regulator overcharging?

My 445 service manual states 12.2-13.8 vdc regulated voltage. I had measured like 14.4 vdc.
This does not sound that high to me, but something is cooking my batteries.

A new VR is ~ $65, with aftermarket on E-Bay for $45 or so. Maybe Stens brand.

 

[Deere Dude]

And for now I am still running the JD battery that I added the acid to.
Remember earlier it would not crank the mower, when I found the level low.

Don't mean to side track your problem but the last time I saw anyone add acid to a battery was 50+ years ago and I may have even been mistaken about that. The only thing that should be added to batteries is distilled water. I have gotten JD batteries and they always come filled and ready to use. Am I missing something?

 

[BBO]

... The only thing that should be added to batteries is distilled water. I have gotten JD batteries and they always come filled and ready to use. Am I missing something?

This 1st JD battery that failed was only 3 years old.
I know all say to never add acid; I keep acid for my 4-wheeler battery.
I know this dealer once failed to fill a new battery completely full.
When you fill a new battery it takes a few seconds to settle in, needing a final top-off.
So I 1st thought they had just failed to fill it full; thus why I added acid.
But now with visible acid on top of the battery I know it's boiling out, for whatever reason.

 

[Richard001]

Another update to my original problem, because it's NOT fixed...
When this 1st started on this I found the battery almost dry, & corrosion was all around the battery.
So with another battery I started working on all this.
Remember my 1st thought was that it might be OVER charging??
So last week the charging light finally came back on.
I find this battery with almost all the acid gone again, after only a few weeks.
I think the voltage regulator is simply cooking the battery.
Is this possible? Has anyone had experience with a voltage regulator overcharging?

My 445 service manual states 12.2-13.8 vdc regulated voltage. I had measured like 14.4 vdc.
This does not sound that high to me, but something is cooking my batteries.

A new VR is ~ $65, with aftermarket on E-Bay for $45 or so. Maybe Stens brand.

You said that you are measuring 14.4 VDC. Is that with the engine running at like half throttle?

Are you measuring across the battery terminals or from the positive to some ground point?

I agree, 14.4 volts should not be harmful for your battery.

Richard

 

[BBO]

You said that you are measuring 14.4 VDC. Is that with the engine running at like half throttle?

Are you measuring across the battery terminals or from the positive to some ground point?

I agree, 14.4 volts should not be harmful for your battery.

Richard

Full Throttle, right across the pos. & neg. battery terminals.
And the light was on when I was reading this.

I plan to check the main engine ground & I will use another Fluke meter to verify this.
So far no one has agreed it's possible for a VR to be putting out too much voltage.

I don't see how it could be related, but the engine is fouling the left spark plug after only 5 hours time.
Compression on the left is ~180 compared to ~210 on the right, so I think it's a cylinder problem

 

[Richard001]

Well this may be way out there, but I suppose it's possible that you are getting a lot of AC across the battery terminals from the alternator. Battery's don't like AC.

Check for AC on your battery terminals.

Also check the current going into the battery while running the engine at full throttle.

Richard