SUPER dead batteries.......

[SargeW]

Here is one I am stumped on.  I have a 08' Ram diesel P/U at the stick house. Low mileage, bought it new in 09'.  On 5/27/12 I replaced both starting batteries as the two original ones had died and would no longer take a charge. 

We left for Alaska in June. As usual I plugged the battery charger (a Save-a-Battery micro controlled charger) into the batteries, which stays connected all the while we are gone.  When we got back here in about September, I unplugged the battery charger and the truck started right up. 

I have driven it for the last few months without issue.  About a week ago I decided to plug in my "Save-a-Battery" charger maintainer as it had been over a week since I had driven it.
I plugged it in and the lights came on as usual, so I closed the hood and forgot about it.  I came out today to go somewhere in the truck and opened the hood to unplug the charger.

The first thing I notice is the red "fault" light is on and blinking on the charger. Shoot, that has never happened before.  I unplugged the charger and got in the truck to see if it would crank. Nothing, and I mean absolutely nothing. 

I retrieved my digital volt meter to check the batteries.  On the DC 20 volt range setting, both batteries showed .01 volts!  What??  I took the cables off each battery and rechecked it, both with the same results.  Popping the caps and checking the fluid in each cell showed normal electrolyte levels.

What in the heck could have killed these batteries so badly?? :'(

With nothing to lose, I pulled out my old faithful Schumacher battery charger and set it to 10 amps.  After about 8 hours the batteries showed about 12.4 volts.  The truck started, but just barley.  The lights flickered up and down with the engine RPM.

I turned off the motor, and decided to hook up the Save-a-Battery charger as it is designed to taper off as the batteries charge.  When hooking up the charger, all of the appropriate lights came on, and the yellow charge light was blinking indicating it was charging. 

I don't know if the batteries will take a charge or not.  But what has me baffled is how it happened to start with.  I have never seen a battery with that low of a voltage.  Could the charger pulled the batteries down to zero if it did not click on when I hooked it up to start with? 

Here is a link to the charger that I have.  http://www.shop.saveabattery.com/12-VOLT-50-WATT-Vehicle-Battery-Charger-w-Auto-Pulse-2365.htm

I have used this charger since I bought the truck in 09' and it has worked flawlessly.  Sometimes being hooked up for 6 months at a time. 

Any ideas guy's? 

 

[Great Horned Owl]

Could you have possibly hooked up the charger with the polarity reversed?

Joel

 

[dave61]

That is strange, it would seem to be a malfunction in the charger, which you might never actually see. I would be hesitant to use it again since batteries are not cheap. I guess the only bright side is replacing the little charger is less expensive than batteries if you can save them.

P.S. If you have another old battery laying around you might hook the little charger to it as a test. If you see that fault light again you know it is the charger and you won't have discharged/damaged a good battery.

 

[Gary RV_Wizard]

Only a short circuit would do that. It's conceivable that a battery cell suddenly shorted internally, but more likely the charger was hooked up with reverse polarity and had no protection against it. A buddy of mine mistakenly did the same thing with to his bass boat batteries, even though he had many years experience. It's an all-too-easy mistake to make.

 

[SargeW]

That's a good guess, but its impossible to do. The plug that hooks on to the battery is permanent mounted, and the plug into the charger has one square side and one round side so it's kind of idiot proof.

Now I wonder if the short circuit is a reality.  I haven't checked it yet this morning.

Oh, and I did put the charger on another battery to test it first. I put it on my lawn tractor for about 6 hours and it worked as designed. 

 

[Quillback 424]

Your charger/maintainer has reverse polarity protection so I doubt if that is what happened. Outside of a battery short I only have one guess. Did you check the DC leads on the maintainer to see if you may have pinched them (positive side) in contact with the chassis when you closed the hood? Or, is it possible that the maintainer connection to the positive battery terminal may have contacted the hood when it was shut? Or the same positive maintainer connection making contact with the battery hold down frame?

I know it's a new truck but since the original batteries failed in only three years I might give a good look at that positive battery cable run for any chaffing or wear points.

 

[catblaster]

Sarge....I had a similar situation a while back and found a diode in the alternator was bad, it acted like a short.

 

[John From Detroit]

I had something like that happen to me several cars ago. turned out to be a bad ground believe it or not.... ON THE ALTERNATOR.. Dang near looked like Kojac after I found that one (NO hair left).  One star washer later, all was good with the world, or at least the electrical system in the car.

You might have accidently left something turned on too.

Super dead DEEP CYCLE batteries.. I am sorry to say I've done that a few times to my Interstate U-2200's and ... they recovered. (this is off topic in this thread)

Starting batteries.. however, Always got replaced after that. Not much chance of recovery.

 

[mylo]

That's a good guess, but its impossible to do. The plug that hooks on to the battery is permanent mounted, and the plug into the charger has one square side and one round side so it's kind of idiot proof.

Now I wonder if the short circuit is a reality.  I haven't checked it yet this morning.

Oh, and I did put the charger on another battery to test it first. I put it on my lawn tractor for about 6 hours and it worked as designed.

Yes, the plug is idiot proof, but are you sure that the permanently mounted pigtail on the battery is hooked up correctly?


Mylo

 

[bucks2]

The answer could be very easy. Here's how a friend of mine did it.

I have the 1 amp trickle chargers on all my vehicles which sit for 7 months while we snowbird. Modern vehicles all have parasitic draws that will kill a battery if it doesn't get regular use or charging. I also have my friend drive the vehicles for an hour or so every month to keep bearings and seals well lubricated. He was not used to the particular way the headlights turn on and off on the wifes car, even though his wife has one of the same brand so it seemed normal for him.  The older model that my wife has, turns the lights off differently, and he accidentally left the parking lights on, which between the parasitic draw and them, draw more than the amperage that the trickle charger puts out. The battery was stone dead the next month.

Look and see if maybe a similar thing happened to you.

Ken

 

[SargeW]

Did you check the DC leads on the maintainer to see if you may have pinched them (positive side) in contact with the chassis when you closed the hood? Or, is it possible that the maintainer connection to the positive battery terminal may have contacted the hood when it was shut? Or the same positive maintainer connection making contact with the battery hold down frame?

I know it's a new truck but since the original batteries failed in only three years I might give a good look at that positive battery cable run for any chaffing or wear points.

I doubt the leads were pinched as the battery and the charger sit way below the hood opening. I will check the entire run on both cables though.

Sarge....I had a similar situation a while back and found a diode in the alternator was bad, it acted like a short.

Interesting thought. Would that effect the batteries without ever starting the truck?

I had something like that happen to me several cars ago. turned out to be a bad ground believe it or not.... ON the alternator....

You might have accidently left something turned on too.

Super dead DEEP CYCLE batteries.. I am sorry to say I've done that a few times to my Interstate U-2200's and ... they recovered. (this is off topic in this thread)

Starting batteries.. however, Always got replaced after that. Not much chance of recovery.

I will also check the ground on the alternator. I really doubt I left anything on though. If I can get the truck running I will take it somewhere and get the batteries load tested. Hopefully they will come back from the dead.

Yes, the plug is idiot proof, but are you sure that the permanently mounted pigtail on the battery is hooked up correctly?

Pretty sure. While I was gone to Alaska for 4 months the batteries were hooked up on the same charger the same way. The truck fired right up when we got back.

he accidentally left the parking lights on

Look and see if maybe a similar thing happened to you.

Ken

While not impossible, it's not real likely.  Where it's parked I have to walk past it every day. 

Right now I am leaning towards a bad cable or ground. I checked the charger a few minutes ago and all looks good, so far.  I need to go out and put a volt meter on them again.

Edit: Fixed quote tag.

 

[Mavarick]

Sarge, if all the easy stuff looks good then I would agree with Cat, bad diode. They will short to ground and pull the battery down in a few days. Easy enough to check with a VOM. Use the amp draw scale and take a reading at the battery as if you were looking for a parasitic load. Unhook the large wire going to the back of the alternator and take your amp reading again at the battery. If the problem is in the alternator you will see it.
This is similar to the old units that had external regulators that would stick and drain the battery. Good luck.

 

[catblaster]

Sarge..... if you do find out its an alternator, I have a Chrysler alternator you can have, just rebuilt and I'll never use it #71 13245. It was given to me but I have nothing mopar except our YJ jeep and it's running Chevy drivetrain.

 

[SargeW]

Maverick, thanks for the tip, I will try it tomorrow.  Thanks for the offer Will, I will let you know how it goes. 

FYI, I took the truck out today. I went out and put a volt meter on the truck and it showed 12.5 volts. I held the meter on the battery as the DW turned the key. While the grid heaters were running it dropped to 11.5 volts. When the grid heater kicked off it came back to 12.2 volts.

I took it out for a drive and it ran great. The on board meter showed the batteries charging at about 14+ volts.  So far the batteries and the charger are acting normal. If the diode in the alternator is bad, will it still behave that way?

 

[Mavarick]

Each situation will behave differently but they could/should still charge even with a bad diode depending on how it fails. One of the reasons the diode is there is to prevent discharge like what you are experiencing. The only way to know is to measure amp draw to see what you really have. You know its charging by the volt gauge so something is pulling it down prematurely.

 

[SargeW]

Does the diode check happen with the truck running or not?

 

[SargeW]

Well the battery charger went into float mode today. I pulled the truck out did some tests on the charging system.  It looks like the batteries have returned to full health, much to my surprise.

The alternator has tested well. The diodes do not seem to be affecting the batteries in any way.  A charging test showed that it it putting out 12 to 16 volts, and it was able to keep up with the demand of everything electrical running in the truck at the same time.

All connections, cables, and grounds appear tight and in good shape. So I am left with the possibility of the charger glitched on me. It's not that old, about 2 years, so I will call the company and see what they say. It's worth a shot.

 

[Mavarick]

Sarge, the diode test happens with the engine off. Unhook neg cable at battery and insert VOM as if you were just checking parasitic loads. See what the amp draw is with everything off. Then unhook the power lead on the back of the alternator that ties it into the battery circuit. With that unhooked, take your amp draw test again. If you have a bad diode you will see a difference between the two tests.
Usually a bad diode does not cause very much trouble, especially if you run the rig every day. The alternator will still keep things charged, just not for 3 or 4 days of sitting. The longer it sits the lower the battery voltage goes because of the diode shorted. In time it will cause other problems which can lead to a battery replacement before the true cause is determined.
I'm certainly not saying this is it for sure, just an option if you can?t find anything else. I'm with you also on the charger not being the likely culprit but you never know.

 

[SargeW]

Thanks Maverick, I did the test both ways. No drop either way. I will keep an eye on it for a few days and see if there a're any unusual drops in voltage.

 

[dirko]

Hi Ho:  It sounds like the dreaded intermittant.  My old Suburban has one, too.  I'm still not sure, but think that one of the door switches that turn on the inside lights is intermittant.  I too would see if the lights were on, but I'm not there 24 hours a day.  Anyway, the first thing to do is to put an ammeter on the battery to make sure something in the vehicle isn't drawing power.... well, besides the clock or other parasitic loads.  Good luck.