Charging System Service Now

[Edkiefer]

Yes, those measurements were taken after the battery was on a Battery Tender for a week, and then taken off.

And during the measurements, the battery was connected with hood up, and I made sure I never opened a door or made anything come on during the 10 days I took voltage measurements across the battery.

Ok, That makes more sense , but if you don't mind me commenting, I would of like to see the graph flatter from around the 12.65-12.55 area .

Did you have problem with this battery getting run down , discharged a lot ?

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[davekro]

$14 for this one :

http://www.amazon.com/Hikeren-Bluetooth-Automotive-Diagnostics-Scanner/dp/B014MTAYK0

I bought a Bluetooth OBDll reader for my Wife's Plug in Prius a few years ago to monitor systems more deeply. I did not think of it for code reading. I'll try to find it in her car when she tries to get home tonight and see if I can figure out how to read codes with it. I had an app on my Samsung S5 That I used with it before. Too bad you cannot ask to have a Ford alternator replaced under warranty with a better than OEM unit. God knows it would even cost less. ;) Before I schedule an appointment with Stockton Ford, I'll ask if they have an alternator in stock. If not choose a dealer that does to be able to get out in one day.

I certainly would replace any OEM battery with a larger capacity one if at all possible (more than stock 590 CCA on the V6).

 

[GT Pony]

Ok, That makes more sense , but if you don't mind me commenting, I would of like to see the graph flatter from around the 12.65-12.55 area .

Did you have problem with this battery getting run down , discharged a lot ?

No issues with my battery. The car only had ~1400 miles at that point. I wanted to get a good baseline of the self-discharge in the car.

I've done exactly this type of battery self-discharge in other cars and the shape of the curve is basically the same as I posted above for my GT. That's just the way a normal battery will self-discharge. The scales are linear on that graph, so it shows an accurate discharge curve.

 

[Edkiefer]

No issues with my battery. The car only had ~1400 miles at that point. I wanted to get a good baseline of the self-discharge in the car.

I've done exactly this type of battery self-discharge in other cars and the shape of the curve is basically the same as I posted above for my GT. That's just the way a normal battery will self-discharge. The scales are linear on that graph, so it shows an accurate discharge curve.

ok , I guess it depends on how much load the vehicle pulls .
I was curious and just so happens my 2008 Honda Accord needed charge .
I didn;t test many days but got these results in 3 days .
Starting voltage 12.75 (after few hr of 10amp charge)
1st day 12.65
2nd day 12.61
3rd day 12.61

I tested load and it pulls 10ma after 15sec of battery connected .

 

[GT Pony]

ok , I guess it depends on how much load the vehicle pulls .
I was curious and just so happens my 2008 Honda Accord needed charge .
I didn;t test many days but got these results in 3 days .
Starting voltage 12.75 (after few hr of 10amp charge)
1st day 12.65
2nd day 12.61
3rd day 12.61

I tested load and it pulls 10ma after 15sec of battery connected .

Yes, the shape of the discharge curve will be dependent on the parasitic load from the car and the battery's capacity and health.

In your example above, the starting voltage of 12.75 seems low to me if that was within a few hours of removing the charger. It took my battery almost 24 hours to reach 12.75 volts. It took ~5 days to reach 12.60 volts.

Once you obtain a baseline like this, you could measure the voltage after a week and compare to what it should be on a new battery to get an idea of the battery's health and if there are any abnormal parasitic current draws going on.

 

[Edkiefer]

Yes, the shape of the discharge curve will be dependent on the parasitic load from the car and the battery's capacity and health.

In your example above, the starting voltage of 12.75 seems low to me if that was within a few hours of removing the charger. It took my battery almost 24 hours to reach 12.75 volts. It took ~5 days to reach 12.60 volts.

Once you obtain a baseline like this, you could measure the voltage after a week and compare to what it should be on a new battery to get an idea of the battery's health and if there are any abnormal parasitic current draws going on.

yes, it will go higher if i leave in on low 10amp charge , something like 12.85 after it settles (right after you will get 13v or so but thats not real values the battery can hold)

I think the parasitic load has a lot to do with vehicle features , my LX Accord is lowest trim so has very little electronic feature (not even radio code) .
Were new vehicles have a lot more features , alarms etc .
Anyway, don't want to get off topic with OP and his issue.

 

[GT Pony]

I think the parasitic load has a lot to do with vehicle features , my LX Accord is lowest trim so has very little electronic feature (not even radio code) .
Were new vehicles have a lot more features , alarms etc .
Anyway, don't want to get off topic with OP and his issue.

True. Typically, most modern vehicles will have a parasitic current draw of 10 ~ 20 milliamps. And with that kind of draw, you will typically see a self-discharge curve like I posted earlier.

 

[davekro]

Cause of 'Charge System Warning' found!

Finally got around to jacking the Mustang up to rotate the tires AND look for the needle in the haystack of mouse nibbled wires I believed to be causing my dash warning light. Luckily, it was in an accessible and visible place. I saw the tiniest disturbance of the cloth type tape wrapped harness (from alternator) just below and rearwards of the oil filter. I saw a tiny hint of green and with a magnifying glass just a few impressions in the tape, Pulling back the tape, I was elated to find a single severed 20 ga. wire! Woo Hoo! I spliced & soldered in a connector, shrink wrapped and retaped up.

Warning light gone now.

If anyone has a wiring diagram, I'd be curious of what that 20 ga. light green w/ red stripe wire did. I ran it fine for 2 months before tracking and fixing the problem. Maybe a monitoring circuit, as it always charged at 14+ V.

Side note: In case the Oil filter on my V6 looks non standard ;)
I used an adapter to change to a full sized filter (I used Purolator PSL3001) because I run Mobil One full synthetic (15K gold label) oil and don't want to risk a smaller surface area filter to not do as well filtering for my planned 10,000 mile interval oil changes. If it is overkill, it still makes me feel good.


Harness from alternator after freeing it from a few tie downs and cutting back the outer tape.

Repaired wire before retaping and also covering with additional harness cover.

Now to prevent future mouse troubles when the car spends it's 3 days/ month parked in a storage yard (basically in a rural field), I I sprayed the harnesses with a peppermint oil spray. I also used mini citrinella tea light candles and pieces of Irish Spring soap, smells which mice are supposed to avoid, hung a few places in the engine compartment and near each rear wheel. I hung a lot MORE of these items in and on my box van which lives at this storage lot most of the time. Last month I found the GMC van with four spark plug wires completely eaten through. That sucked and had me doing lots of rodent repellent research!


Here is the GMC's rodent damage (under the engine cover in the cab).

PS. Glad I did not take it to the dealer assuming it was a warranty issue!

 

[GT Pony]

Here is the GMC's rodent damage (under the engine cover in the cab).

PS. Glad I did not take it to the dealer assuming it was a warranty issue!

Wow ... works good as an anti-thief system too. :doh:

 

[davekro]

Wow ... works good as an anti-thief system too. :doh:

Surprisingly it actually started and moved, but with obviously not much power! ;o)

 

[GT Pony]

Surprisingly it actually started and moved, but with obviously not much power! ;o)

The GM moved with no spark plug wires? ... must be new alien technology.

 

[347CobraII]

That's small chewed on everything that mouse was hungry. Try the city garbage trucks they chew everything. 2 years ago one caught on fire and took 3 others with it. They now all come with battery disconnects not option anymore

 

[davekro]

The GM moved with no spark plug wires? ... must be new alien technology.

Well, the other bank still had 4 wires connected... so only 175 cid firing. ;)

 

[davekro]

That's small chewed on area mouse was hungry. Try the city garbage trucks they chew everything. 2 years ago one caught on fire and took 3 others with it. They now all come with battery disconnects not option anymore

Well that is food for thought. Since this truck sits idle for a month at a time, years ago I installed installed a battery disconnect but have not used it for a long time. I'll start using it now as cheap insurance against such a catastrophic possibility by spending the 2 mins to use it ( now it's in rodent territory)!
Thanks for the heads up

 

[347CobraII]

But them freaking mice live in the truck while in use. At least there not rats that jump out the packer in there shop.


I was taking car apart took panel off that had insulation on it. Seen it was puff up some I pushed on it through it was ok. Damn mouse jumped out on my arm then down my shirt then to the floor and outside it went.

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