suddenly, slow cold cranking. Strange smell?

[MacAndrew_Jack]

Hey TDIers,
I have an ALH that I drove 500 miles last weekend, and started in cold mountain weather over several days, no problem. I drove home after all that, and now it is slow cranking on startup, not starting. When I charged the battery with a trickle charger, it started. So it seems to be the battery, but why would it suddenly fail like that? The VLT reading on Scanguage says 12.0 at rest then 14.1 when running. A voltmeter directly to the battery read 12V, before the charging.
Could I be missing something else?
The battery is less than a year old, and has been bomber the whole time.
I was driving with 150w aux lights, as I usually do. At some point on the last drive home before the problem began, I noticed a smell of what I thought was the marinara sauce from our takeout (tasty fried mac and cheese balls with marinara dipping sauce from Endo's grill in Copper, CO). It isn't going away easily in the cabin and I wonder if it is van related, but I can't find where it is coming from if not the actual marinara sauce, now removed. I smelled in both battery compartments and the smell is not coming from there. Is this a red (marinara) herring or could there be a marinara version of electrical smell indicating a short that is draining the battery? I don't smell any typical electrical smells.
Or is the simplest explanation (battery suddenly not holding a charge) applicable.
Thanks in advance.
-macjack

 

[JB05]

12.0 is low for a battery; should be closer to 12.6 volts. I just got rid of a Sears battery that was showing 12.0 volts sitting over night. I keep digital volt meter plugged into the cig. lighter which allows me to get an instant reading before disarming the alarm. Did you check the fuses on top of the battery?

 

[MacAndrew_Jack]

Not sure which fuses you mean, JB05. This TDI is in a nonstandard application (Vanagon) so locations of things are different. I haven't checked fuses, but all electrical functions are working (radio, lights, etc.).
I am trickle charging again. I guess in the back of my mind I wonder between battery and starter, and why a battery showing 12.0 is not turning over the motor, but then when it sits on the charger for a few hours, it does? I could simply bring the battery to the shop that sold it to me and see what they say about its condition, and presumably it is under warranty so it could be replaced.
But what fuse could I check, again?
-macjack

 

[Jersey John]

12.0 volts is a little on the low side for cranking a cold diesel. Depending on the manufacturer and the cold cranking amps. I always buy Interstate and the biggest CCA'a i can get.

With the smell????? maybe one of the cells in the batt????

 

[RacerTodd]

Depending on the ambient temp, 12v indicates a battery with a low state of charge.

This chart shows the battery state of charge versus voltage.

Find the battery temp in deg F on the left. Use the ambient temperature of wherever you park your car. Once the car sits for a few hours, the battery temp will be about ambient. If you've just parked the car, the battery will be much warmer since it's in the warmer engine compartment. Best way is let the battery sit for a few hours to come down to ambient temp.

Read the voltage of the battery and using the chart you can roughly figure out the state of charge of the battery. Note: for a sealed, maintenance-free battery (no removable caps) add 0.1 volt to all numbers on the table.

Note: you have to remove the surface charge from the battery before using this chart to get accurate results.

Surface charge is the uneven mixture of sulfuric acid and water along the surface of the plates as a result of charging or discharging the battery. It will make a weak battery appear good or a good battery appear bad.

The surface charge can be eliminated by one of the following methods after recharging or discharging a lead-acid car battery (remember running the engine charges the battery as well!). This step is not needed if the battery has just been sitting unused for several hours.

1. Allow the battery to sit without discharge or charge for between six to twelve hours at room temperature. (Recommended method.)
2. Turn the headlights on high beam for five minutes, turn them off, and wait ten minutes.
3. Disable the ignition, turn the engine over for 15 seconds with the starter motor, and wait ten minutes.

 

[MacAndrew_Jack]

Wow, RacerTodd, That is some great info. Thanks!
I took the battery to the battery place that sold it to me and they tested it. I was running 180 out of 880 CCA, and was determined to be DOA. So it appears that it had suffered a catastrophic, sudden loss. Replaced with a new one under warranty and I am off and running.
Still not sure about the marinara smell. It did come on in the last drive before no-start, so go figure.
The surface charge issue is new to me. Supposedly we got rid of the surface charge when he asked me to turn on my headlights, which I did but only for about 5 seconds, then he immediately tested the battery, so perhaps he didn't follow all the protocol to actually discharge it. At any rate, no skin off my back, but perhaps they have a better battery than they think there in my return? I wonder what would have happened if we ran the protocol you suggest. In the winter, #2 seems easiest. I did experience a similar battery failure a year ago, also in cold temperature, which is when I purchased this one. I think I will have to try out the discharge method in the future when experiencing sudden battery failure.
I am just glad that the Syncro is running since the snow is dumping here in CO and I plan to drive up to Copper (with everyone else on I70) tomorrow.
Thanks for the help everyone.
-macjack