devbolt
Posts: 459
Joined: Wed Sep 28, 2016 2:17 am
Location: Bay Area, California.

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

Wed Dec 06, 2017 8:48 am

LeftieBiker wrote: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.

SeanNelson
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Location: Vancouver, BC

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

Wed Dec 06, 2017 10:29 am

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.

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

Wed Dec 06, 2017 11:04 am

devbolt wrote:
LeftieBiker wrote: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.

desiv
Posts: 33
Joined: Mon Oct 30, 2017 5:00 pm

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

Wed Dec 06, 2017 4:06 pm

LeftieBiker wrote: 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

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paulgipe
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Location: Bakersfield, California 93305
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Re: Our Bolt is Back or How a 12-Volt Battery Can Kill an Electric Car

Thu Dec 07, 2017 12:16 am

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
Paul Gipe
Bakersfield, California
2017 Bolt LT with DCFC, leased 11/09/17
2015 Nissan S with QC, leased, returned 11/10/17
2013 Chevy Volt Premium, bought used 10/3/16
L2; ClipperCreek HCS-40; EVSEUpgrade; Jesla; JDapter Stub
www.wind-works.org

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

Thu Dec 07, 2017 5:27 am

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.

BoltMaybe
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Joined: Fri Sep 15, 2017 7:20 pm
Location: Portland, OR

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

Thu Dec 07, 2017 8:32 pm

LeftieBiker wrote: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.
EV Ownership History
2017 Chevy Bolt Premier
2014 Mercedes B-Class
2011 Nissan LEAF

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paulgipe
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Location: Bakersfield, California 93305
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Re: Our Bolt is Back or How a 12-Volt Battery Can Kill an Electric Car

Fri Dec 08, 2017 2:01 am

Yes we need a Bolt Spy though Chevy really puts a scare in the manual. I used Leaf Spy for nearly three yrs without problems.
Paul Gipe
Bakersfield, California
2017 Bolt LT with DCFC, leased 11/09/17
2015 Nissan S with QC, leased, returned 11/10/17
2013 Chevy Volt Premium, bought used 10/3/16
L2; ClipperCreek HCS-40; EVSEUpgrade; Jesla; JDapter Stub
www.wind-works.org

Collimare
Posts: 22
Joined: Sat Nov 25, 2017 3:58 pm

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

Fri Dec 08, 2017 2:28 am

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).

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

Fri Dec 08, 2017 4:50 am

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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