Our Bolt is Back or How a 12-Volt Battery Can Kill an Electric Car

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paulgipe

Well-known member
Chevy Bolt Supporter
Joined
Feb 19, 2017
Messages
228
Location
Bakersfield, California 93305
The good news is that our brand-new Chevy Bolt EV is back from the service department. The bad news is that after only eight days in our possession it had to be towed from our house to the Chevy dealer because it wouldn't start.

That's actually an understatement. It was a very dead Bolt. The key fobs wouldn't even open the doors.

RTEmagicC_2017-Bolt-on-Tow-Truck_20171118_01.jpg.jpg


Being a nerd, I'd read the section of the manual for what to do when the fobs won't open the door. So I proceeded to figure out how to take the plastic cover off the door handle without scratching the paint. Fortunately, the mechanical key will pop the handle cover off safely. I did so, entered the car, proceeded to take everything out of the center console that we had just put there, and carefully placed the fob in its designated position.

Nothing.

Not a flicker, not a buzz, not a beep (and modern cars are all about beeping at you). Nothing. Dead, dead, dead.

Now it was time to get serious. I popped the hood and dragged out my Fluke volt-ohm meter (VOM in the trade).

3.7 volts.

That's a long way from 12 volts. I don't think I've ever measured a starter battery with such low voltage.

I should interject here that electric vehicles (EVs) use a 12-volt or starter battery to power all the electronics. Without the 12-volt battery an electric car won't go anywhere. You can't even put the car into neutral without the 12-volt battery powering the car's computer. And the computer controls everything. So, despite what most people think, that big, powerful lithium-ion traction battery can't do anything if the 12-volt lead-acid battery is dead. It's the weak link in all EVs.

Our other car is a Chevy Volt--that's the one with the "V" for victory. Its starter battery is in the rear. To jump-start the Bolt with the Volt I'd have to back the Volt up to the Bolt. You can see how this quickly gets complicated.

The Bolt is a brand-new car with a lot of very expensive electronics. The last thing I wanted to do was make whatever problem the Bolt had worse by cooking something that shouldn't be cooked.

Rather than being macho and jump-starting the thing myself, I thought the better part of valor was calling GM's OnStar service and asking for a tow truck to take it to the Chevy dealer. They surely would know how to fix whatever was wrong. . .

I have no complaints about OnStar. They answered the phone, were polite, and arranged for a tow truck. However, the call shows how little EVs have penetrated the automotive world. The OnStar technician started to ask me questions--from a script no doubt--about my problem. He began with, "Did it turn over?

EVs don't "turn over." They don't have an engine. The "starter" battery is called a starter battery because it's used to crank the engine to start a conventional car. In an EV we might better call the 12-volt battery the "accessory" battery, which it is.

Once OnStar was straightened out on the fact that the Bolt is an EV, they promptly scheduled a tow truck--with a "dolly." The car's front wheels were locked in "park." To get the car on the truck they'd need the dolly.

Of course the tow truck arrives without a dolly. The truck did have "skids," but the driver quickly saw they weren't going to work. He then decided to jump-start the car so he could put it in neutral, which he did.

Off he went with the Bolt on the back of the truck. Chevy called to say it had arrived.

And there it sat--for days.

I called repeatedly. No one answered the phone. So I left a message every day the car was on the dealer's lot.

Finally, I asked our salesman to intervene and that worked. The service department called and asked, "Why is the car here?"

This was exasperating and not a good omen for ownership of a new Chevy. There was a digital trail on this car from the time I called OnStar.

So I described the problem to the service adviser and he informed me the car looked fine. I explained that we'd only had the car eight days and it shouldn't do that. He offered to run diagnostics on the battery and charging system. They did, found nothing, reset the "trouble codes" and called to say it was ready to pick up.

When I went to pick up the car--six days after it was dropped off (including the Thanksgiving holiday)--it still had the towing eye in the front bumper.

For the next few weeks I'll keep my VOM handy and I'll check the voltage periodically. So far it's holding a charge, and if you keep the VOM on the battery while the car's at rest, you can see the car trickle-charging the battery as voltage slowly climbs from the initial measurement.

What happened to our Bolt remains a mystery. Our battery was made in Korea (as was much of the car). The battery in our friend's Bolt was made in Germany. They haven't had any problems.

The problem could have been due to "operator error." I could have made a mistake. I don't think so, but one never knows for sure.

Our Bolt had sat on a dealer's lot in the LA area for at least six months. There was only 33 miles on the odometer when we received it. Theoretically, during the first 500 miles the car is driven, the computer's software charges the battery at a higher voltage than normal, so that when the car is delivered to the customer the starter battery is fully charged.

I did notice that when I drove the Bolt back from the dealer at dusk the headlights came on. When they did, the background for the instrument cluster and the big "infotainment" screen switched to black from the default white. I hadn't noticed that before. In fact, I had been thinking about mentioning to my wife Nancy that we needed to find a piece of cardboard to cover up the big screen at night. It was so bright that it made it hard to see through the windshield. Either my memory is faulty (always a possibility) or something happened during the car's visit to the shop.

The message boards for both the Nissan Leaf and the Chevy Bolt have extensive discussion on the 12-volt battery and what happens when the battery fails. The starter or accessory battery is a key component of an EV, and early Leafs had a number of failures of the 12-volt battery. However, we never had a problem in the three years we drove a 2015 Leaf.

Until I am assured the car is charging properly, we're going to keep a close eye on the Bolt's 12-volt battery before we take any road trips.

Now, if I can just find a way to turn off the radio and make that driver's seat comfortable. . .
 
Sorry you got off to such a rough start with your new car! I understand your reluctance to jump your brand new car but that is actually very common for cars that sit on a dealer lot before delivery, EV or ICE. Assuming the 12V battery had a low State Of Charge when it was delivered, the dealer should have done a better job confirming both batteries were topped off at delivery.

The 12V battery is critical from a safety perspective, allowing a safe low voltage battery to power safety circuits engaging high voltage only after all system checks pass. I have seen posts where someone inadvertently left on the hazard lights or interior cabin lights draining the 12V battery and it requiring a recharge, not sure if you could have left a switch in the wrong position when learning about your brand new car, it happens. Page 154 of the Bolt manual talks about "battery rundown protection" however I am not sure which lights are covered.

My radio display dims as you describe, I don't think that is a new feature they updated, just that you first noticed it as you have had so little time with your new car.

Anyway, I hope now that you have it back you quickly are able to build confidence in it and that you and your wife enjoy your new Bolt as much, or more, than your Volt and as much as we enjoy our Bolt!
 
paulgipe said:
Finally, I asked our salesman to intervene and that worked. The service department called and asked, "Why is the car here?"
This was exasperating and not a good omen for ownership of a new Chevy. There was a digital trail on this car from the time I called OnStar.
Hopefully, this just says more about your local dealership's service department.
A dead 12v battery on a new car isn't just an EV issue (although as you pointed out, you can't do anything without good 12v, even in an EV).

Any other dealer options around where you are??

desiv
 
A lot of us Leaf owners had issues with our 12v batteries as well. When the battery would go one of the things that wouldn't work right is the brakes! You'd shift the car into gear and it would start rolling and your foot would go to the floor. Scary as all heck when it happened to me. (Thanks to the Leaf using a solenoid to power the brakes that would discharge and not charge back up)

One of the things I ended up learning that I was until then ignorant of is that 12v lead acid batteries like to be kept topped off all the time. Not a problem in an ICE where the alternator is constantly putting out more power than it can use. Prolonged time at even 80% charge will cause permanent damage to the battery. The Leaf problems were largely caused by a really crappy algorithm for charging the 12v battery.

I suspect your car was allowed to sit on the lot / storage which allowed the 12v to run down. Dealer probably charged it back up before delivery, but the damage has been done.

Dead or dying 12v batteries have also been the bane of Tesla and Prius owners. In the case of Tesla due to battery drain when not in use and in the Prius case it is similar to the Leaf where they went too conservative on the charging logic to help keep the traction battery topped off.
 
paulgipe said:
I did notice that when I drove the Bolt back from the dealer at dusk the headlights came on. When they did, the background for the instrument cluster and the big "infotainment" screen switched to black from the default white. I hadn't noticed that before.

The instrument panel will go to dark background mode with the user-selected brightness setting when the car detects that it is dark outside (when turning on the headlamps due to darkness).

The day mode is customizable to one of two light backgrounds or the same dark background as the night mode. If you set the day mode to the dark background, you may notice it change from full brightness during the day to reduced brightness at night, if you have the brightness setting lower than full.
 
I suggest that you insist on a brand new 12 volt battery, as that one is definitely damaged. And make sure they bench charge it to 100% before installing it. You may also want to invest in a Battery Tender JR, which can keep the battery topped off, although it's small and slow. Hopefully you won't need to do what I did with my Leaf: install it hardwired to the battery, with the connector run into the charging port compartment.
 
This is nearly the same exact story (see thread: Towed To Dealer after 2 weeks 351 miles) as my dead Bolt on Sunday where the dealer basically said "Why is the car here?" on Monday when they got the key from the night drop box where the tow truck driver left it, went out, unlocked it, started it and drove it around the building into the service bay.

This issue is a more complicated than just a faulty battery even if it is a faulty battery. So the battery reads low one day and has a full charge the next day. Two batteries on two different cars with exactly the same mode of failure and miraculous recovery. I don't think so!! Has nothing to due with the charging system which would have topped off the battery each time it was plugged in or running. I can't imaging enough drain on the battery to pull it down that low and then allow it recover fully. Could there be a bad cell that inhibits charge flow and then all of a sudden allows charge flow maybe but not likely. Perhaps an internal safety system shut the car down on purpose. I can buy that but, under no circumstance should an EV ever be allowed to simply power back up on its own when it has been found or rendered dead. It should be fully inhibited until manually reset. This is a very basic hardware and software safety validation issue. It should not happen!!! Period!!!

It is a potential safety/liability issue to me. The EV should not be found dead one minute and then without any external intervention be found fully powered. When does it go dead again? While driving? Only when parked? What if someone assumed it was dead and while working on it, it all of a sudden fully powered back up. Seriously perhaps this should be a NHTSA issue.

I will step out on a limb here and say that your dealer found an issue and is simply not reporting it to you. The dealer still has mine and I have heard nothing after two days.

We can minimize this all we want but to me personally it is a very big issue that needs to be fully investigated, understood and repaired. I am under no circumstances OK with driving an EV that may suddenly die or be found dead that all of a sudden just comes back to life on its own.

What was that a 1958 Plymouth Fury in Christine? At least mine is not red.
 
Dealers don't handle EV 12 volt battery issues well - I don't think they are withholding anything. As for the behavior, it could be a batch of 12 volt batteries with bad cells, or it could be a case of a vampire drain that stops occasionally, allowing the battery to recover enough voltage, just sitting, to start the car. Remember that high amperage isn't needed, just 12 volts.
 
I'm with LeftieBiker on the source of this. This is my 3rd EV and been on lots of blogs and heard many a tale of 12v battery issues turning cars into bricks. I would vote for the ghost load/drain issue for this particular scenario but it does seem like a stretch as batteries don't "recharge" all that much on their own. I always wondered why there isn't a modicum trickle charging from the Lithium pack to help the 12v stay alive while the car is not in use.

That being said, it's not a good thing for a $40k product to totally not function, then work fine w/o intervention. No matter what you can't have this happen with a vehicle that folks depend on to carry out their lives. "Geez I wonder if my car works today. No? Well I'll just take Uber, come back tomorrow, and hopefully it will be fine." Not a good endorsement if you ask me....

Chevy better come up with some conclusive answers for this or the tax credit disappearing will be the last of their worries for their purported EV fleet.
 
I would vote for the ghost load/drain issue for this particular scenario but it does seem like a stretch as batteries don't "recharge" all that much on their own.

Not generally, no. But it's possible for a 12 volt battery to be drained by a continuous load, and then when the load is disconnected, have the inner plate material slowly and very partially recharge the outer plate surface. This would be especially likely in a battery that has developed a "surface charge" from sulfation occurring from a near complete discharge, followed by a recharge that doesn't break of the sulfate crystals.
 
LeftieBiker said:
I suggest that you insist on a brand new 12 volt battery, as that one is definitely damaged. And make sure they bench charge it to 100% before installing it. You may also want to invest in a Battery Tender JR, which can keep the battery topped off, although it's small and slow. Hopefully you won't need to do what I did with my Leaf: install it hardwired to the battery, with the connector run into the charging port compartment.

The Bolt is supposed to automatically maintain the 12V battery if there is sufficient charge in the high voltage battery. I don’t know what level that is, though. Also, if you plug the car in to charge, it will automatically maintain the 12V battery while plugged in. If you plug in every night to charge, or even just once a week, then the Battery Tender Jr may not be necessary.
 
For those that are having 12V battery troubles, it's worth checking out this post from a thread on another Bolt forum. The poster there had the same kinds of issues that folks here are describing, and they were diagnosed by his service department as a software problem that caused one of the modules to think that it was in "service mode". That prevented the battery from being charged when the car was turned on, thus leading to its failure. The dealer applied a software update to the culprit module which has apparently solved the problem.
 
devbolt said:
LeftieBiker said:
I suggest that you insist on a brand new 12 volt battery, as that one is definitely damaged. And make sure they bench charge it to 100% before installing it. You may also want to invest in a Battery Tender JR, which can keep the battery topped off, although it's small and slow. Hopefully you won't need to do what I did with my Leaf: install it hardwired to the battery, with the connector run into the charging port compartment.

The Bolt is supposed to automatically maintain the 12V battery if there is sufficient charge in the high voltage battery. I don’t know what level that is, though. Also, if you plug the car in to charge, it will automatically maintain the 12V battery while plugged in. If you plug in every night to charge, or even just once a week, then the Battery Tender Jr may not be necessary.

The Leaf is also supposed to maintain the 12 volt battery automatically, and sometimes it actually does. It definitely does not do so, however, if the car is plugged in but not charging. The post above mine suggests a more likely culprit, though.
 
LeftieBiker said:
The Leaf is also supposed to maintain the 12 volt battery automatically, and sometimes it actually does. It definitely does not do so, however, if the car is plugged in but not charging.
Leaf side story..
I remember being a bit nervous when I was reading the stories of the 12v issues with the Leaf, but I hadn't had any problems with mine.
Through the 3 years before I traded it in for the Bolt, no 12v issues..

And I kept an ODB2 Bluetooth adapter plugged in all the time for Leaf Spy Pro.

I actually think it was that silly solar panel on the roof of my SL that saved my 12v battery.
I got mine used and it was the one on the lot with low mileage and a DC quick charger. I thought at the time the little solar panel was kind of silly.
It only trickle charged the 12v battery, and couldn't have put too much power in there.. Small panel...

But looking back, I am guessing just that little bit of trickle was able to stave off the possible 12v issues for me....
Maybe all the Leafs should have had that? ;-) (And maybe Bolts too.. )

desiv
 
Thanks every one. I think I linked to that mychevybolt.org thread in my original post.

Yes, this is disconcerting--to say the least. There have been a few other weird electronic issues too. I think my heated seat is coming on automatically and not registering on the dash for example. These are subtle things and I don't always trust my own observations.

A former college professor saw my FB post about this and suggested one of those small lithium battery emergency chargers. I think this may be similar to LeftieBiker's suggestion. I've ordered one and like my Fluke I'll carry it in the passenger compartment for a few months until I am assured this won't happen again.

I think I mentioned the build date. It had sat on the lot for a long time--say 6-8 months. That could have played a part.

But it's the weird electronics issues that have me keeping an eye on everything.

Thanks for the suggestion of a black daytime screen. Not sure where the setting is for that, but I can look it up.

No, this shouldn't happen and it never happened with my Leaf--problem free for three years. ;)

Paul
 
A former college professor saw my FB post about this and suggested one of those small lithium battery emergency chargers. I think this may be similar to LeftieBiker's suggestion. I've ordered one and like my Fluke I'll carry it in the passenger compartment for a few months until I am assured this won't happen again.

I recommend a battery maintainer that plugs into the wall and tops off the 12 volt battery. The above jumpstarters are handy for dead batteries, but don't maintain them.
 
LeftieBiker said:
I recommend a battery maintainer that plugs into the wall and tops off the 12 volt battery. The above jumpstarters are handy for dead batteries, but don't maintain them.
While that is a good workaround...

Unfortunately that might mask that your EV has a nasty problem. So if you park it for a couple of days you might still end up with a brick. What is really required is some feed back in the vehicle about the health of the 12v battery (a gauge not an idiot light that tells you only when it's too late) and/or some diagnostics that puts up a warning message that there is an unusual drain on the 12v battery.

This is info probably on the CAN Bus, so if and when someone creates an App like LEAFSpy for the Bolt, that info could at least be available on your phone.
 
As reported on my thread for the same issue:

Good news I hope!! My service adviser called late today just to let me know it will be going into detail tomorrow to clean the seat and buff out the scratches on the hood. I can pick it up tomorrow.

The issue as he relayed it to me was they found a "draw" and replaced the MPCM2 module (I think, he was going fast) which is the main charging system control. I will know more tomorrow when I pick up the car and can read the lengthy report (as he put it).
 
While that is a good workaround...

Unfortunately that might mask that your EV has a nasty problem. So if you park it for a couple of days you might still end up with a brick.



I don't think we Leaf drivers have ever found a vampire drain that would kill the 12 volt battery while it was charging from even a little 0.75A Battery Tender JR. You still have a point, but that particular outcome is unlikely.
 
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