Could the battery have failed between the dealer test and your breakdown? I’ve heard of situations where plates short out or perhaps even detach, so more of a sudden happening. A battery test is actually fairly quick and not hard f the battery is easy to access, so not seeing a reason that the dealer would not what the chance to sell you a battery and install.
Also with the key on the position that the dash lights were coming on you were drawing a fair amount of power, and just to use the radio the key could be on the ACC position instead of the ON position.
Anyway yes it is a bonehead move to have the positive cable be black for something so critical.
I suppose it’s theoretically possible, but in general batteries have a life of about 3-4 years around here regardless of vehicle because the summer heat is so high. This one was a 2019 purchase, so it was a little bit prior to 3 years, but not dramatically so. I think it’s much more likely that it just failed as they usually do, and that they just looked at it (it was pretty clean looking) without actually hooking it up.
I was in the ACC position… just listening to the radio. I ought to be able to do that for more than 30 minutes without the battery crapping out, even if I had it in “ON”, especially assuming it was fully charged.
The 110K service for any VW product does not mention any checks of the battery or charging system. I don’t see how the VW or the dealer could hold any blame for this issue.
It’s the usual multipoint check- there are a couple of boxes on the checklist - they have green, yellow and red options, and one is “battery terminals/cables/mountings” and the other is “Check condition of battery (storage capacity test if applicable)” Both are listed as ‘green’.
If they’d have actually done it, it wouldn’t have been green and then died after 30 minutes of radio listening four days later.
When I was a locksmith they taught us whenever we were taking something apart, take out your cell phone and take a picture every time you remove something, so if need be you have a guide to put it back together.
I made this a habit in my life and it’s saved me dozens of times.
Don’t know that I would have done that with a car battery though. Dang Germans.
“back in the day” a car battery was larger and had fewer plates in it. They had less power than a modern battery. They would also fade away slowly. You got a warning in the form of a slowly turning starter.
A modern battery can show it’s up to grade and then completely grenade while you’re driving because of the closer spacing of the plates. Usually you get 4+ years of use from them. If it were a 5 year old battery then they should have explained it to you so you could make an informed decision.
If you jump-start a battery that has died and get the car running you can tell if the battery is shot by tuning into an AM station. You’ll get static from the alternator because the battery acts like a filter.
Also, if your alternator dies then your car’s PMC (Power Management Computer) may start shutting off accessories like the radio and blower motor to conserve the battery. So if you start to get a series of items shutting down then you may need an alternator.
Something I keep in each car is a USB charger with a volt meter so I can monitor what is going on to avoid what you went through. Been there done that. Something like this. There are all kinds out there to choose from.
On my Subaru Outback I had a bad alternator and was driving it for all the battery was worth to make it to a safe spot to leave the car, also I knew I needed a new battery anyway so want to get as far as I could. I was very impressed at the system failures. Each system that went out happened from least essential to most essential. Lights on the dash came up in that order. IIRC the antilock were one of the first to go, loss of AWD came on a bit later with a few others like blower and radio, I think the turn signals also failed towards the end along with the dash gauges.
I could deal with a black wire but it should have a red indicator on the end plus a red hood to keep from arcing it with tools. I’ve never seen a modern car that wasn’t set up like this but that’s not saying much. It’s not like I have a huge sample to work with.
I was after I figured out what was going on. I’d never heard of a PMC. I figured it out when I drove away and everything started to shut down. I thought I was blowing fuses at first. Then it dawned on me that the vehicle was doing it on it’s own. I turned around and headed straight for home. That is what got me to buy a volt meter/USB charger for all cars.
I’d much rather have an alternator light come on and do my own triage. What happens when THAT computer dies?
I watched a Youtube video of a guy restoring a mechanical clock yesterday and after disassembly and cleaning, a tablet suddenly appeared propped up on the workbench. It had not just photos but video recordings of what he had done taking that particular stage apart.
I did have that light on also till I totally lost the dash display info. So I could do some triage, however there was no practical way to turn off ABS or AWD function, and for that matter the dash panel. But yes it was a partnership in triage, we both took action.
I also assume that when ‘that’ computer would need to shut down so would the ignition, though I can not be sure as I reached my safe location before total system shutdown.
I would hope that the ignition, fuel injectors, and radiator fan are NOT connected to the computer. It should only be allowed to control non-critical items.
That’s pretty cool. The one time I had to drive 40 miles in a snow storm with a dead alternator I had to shutdown systems myself. Lights? Normally yes, but they’ll stay off until sunset. Rear defogger? Normally yes, but who really needs to see where they’ve been. Blower? As low as possible to keep the front window clear. Heat? cranked to the max, as that doesn’t use the alternator, and saves the blower, even if the car is now 80 and I’m wearing a winter coat. Wipers? As needed.
The VW I had required removing the headlight assembly to replace the battery. It wasn’t that difficult, but did turn a 3 minute job into a 20 minute job.
On that car I also had batteries seem fine, right up until they weren’t. Still doesn’t excuse the mechanic of claiming to have checked it, when they didn’t. I suspect a dying battery would fail a load test a few days before it gave up for good.
I once got a car back after normal kind of oil change stuff with one of those 29 point checks and everything labeled as “good” to have it blow a coolant hose the next day, at the Eisenhower tunnel (top of the continental divide on I-70 in Colorado), during the super bowl, while the Broncos were playing. “The tow truck can’t be there for four hours.” “Yes, I understand.”
Even though I had no complaints about the work that shop actually did, I never went back because I couldn’t trust them after that.
This is consistent with what I’ve learned from previous threads about car batteries, which makes me wonder whether the OP’s battery could legitimately have checked out just fine.
That said, “grenade”? Is that an autocorrect replacement for “degrade,” or a use of the word that I’m not familiar with?
For all their faults, you’re better off with a dealer or an independent than with one of those Jiffy Lube joints. Upselling incompetent assholes, for the most part. Years ago I took my Jeep to one for an oil change. They of course tried to upsell me to an antifreeze change and transmission fluid, etc., which I turned down. Paid my bill and left for home, which was about a half mile away. Next morning I go down to the garage and back out, and as the door is going down I notice a dark splotch on the garage floor.
I go back in and see that it’s oil, of course. I look under the Jeep and there is oil splattered all over the undercarriage. So I immediately went back to the Jiffy and told the guy the problem, and he tries to tell me it must be my fault! “Let’s see: I drove in here without a problem; you futzed around with my vehicle; and now I’ve got oil leaking out of it. Explain that to me, please.” “Well, maybe you hit bumps on the way home and loosened the oil plug.” “Again, I didn’t have that problem until YOU changed the oil. Try again.” Turns out, they managed to lose the O-ring that seals the pan plug.
See, I’d think that Jiffy Lube would be safe; given that oil changes are all they do and they’re doing them all day long, I would think they’d be good at them. But yes, losing the O-ring is a dumb mistake. (I’m guessing it fell into the collection basin and is at the bottom of a whole lot of dirty oil.)
Yeah, the car is now fixed. Apparently hooking the batteries up backwards will blow something called the “multifuse”, which seems a bit Fifth Element-ish. Now that it is replaced and the codes are all cleared, I’m good to go.
The service manager gave me a long list of BS about why their guy tested it and it was OK on Wednesday, but was dead on Sunday- the weather changed, the cell could have died in the interim, it’s not an “official” VW battery, some nonsense about amperage testing vs. voltage testing, and so on. Basically she took the approach of “if it says it was OK on the check, he did the test”, so there must have been some other reason.
I’m pretty convinced he never actually tested it- he just looked at it and since it was clean and not gunked-up like most old batteries are, with corroded terminals, etc… he assumed it must be ok and went along with his business. Because like you say, unless a cell croaked in the 4 day interim, it should have read low on voltage (which is how you test it… see below), at least a little- here are the car battery voltages for testing. I would have figured that it would have read something other than 12.6V- probably south of 12.4, and likely south of 12.2 at that point.
Car batteries provide 12.6V DC (direct current) through six cells, producing 2.1V each.
~12.6V: fully charged
~12.4V: 75% charge
~12.2V: 50%
~12V: 25%
11.9V and below: effectively zero charge
