Unfortunately, poor 12v batteries seems to be a trend in PHEV/EVs. The Niro has issues, Tesla has issues, and so have others. They only seem to last 2-3 years at best.

 

I tend to think it's the use case. The batteries are lightly used while ICE 12V are deep cycle. Further they get 'feather charged', where it's constantly drawing from and topping off. Further I think lead acid likes some deep cycling. My high end UPS deep cycles the batteries regularly - EV's should probably do that.

Anyhow I found a number of disconnected posts here about the 12V going bad (in one case taking out the inverter too?), so it does seem to be a problem. Anyhow I'm just glad it's not something serious. Key point here is that the system is not good about detecting a bad 12V. We've been chasing this for a year or two. I think what happens is because everything depends on a reliable 12V, if that droops or whatever then systems start going haywire.

 

I use a "battery minder" {like a trickle charger} one night every month and have had NO issues in 53 months. Keeping my fingers crossed!

 

I have the OBD-12 BatteryMinder installed on my Bolt battery and my Prius battery. It uses the same pulse technology as the BatteryMinder chargers except it only desulfates when the vehicle is on and shuts off when the vehicle is turned off. It is installed next to the battery and connected tot he battery posts. Time will tell whether it extends the life of the batteries. I got 8 years out of each (two) Prius I owned before being replaced but I did not have the BatteryMinder installed on them.

 

Only time I have had battery issues in my Bolt was when I had enabled keypass and turned on approach detection. I'm assuming the car kept thinking I was approaching it as I was walking around the house with the keys and phone in my pocket and kept cycling the lights on. Next morning when I went to go to work, the 12V battery was completely dead. Like 6V dead. After jumping it and getting the APU running I haven't had any problems since, 1.5 years later. Same 12V.

 

We've had issues with the 12V battery for a year or two with our 2017. Several times there wasn't sufficient power to sufficiently boot the car for startup. But then after charging it a bit it would be fine (either through driving or a jump start). The dealership said it was fine, and for a while I thought that the problem was related to an odd bad habit I had of turning the car off without having it in park (we thought that there might be a bug where something gets left on accidentally).

Anyhow this week it got really stuck while at the grocery store. I was able to jump and get it home, but then it developed a dummy warning light stuck on, and OnStar said there was a flag for the "Drive train control unit anomaly". Dealer decided it was the 12V, and called up Chevrolet to get a new one only to find .... wait for it ....

Other Bolts are experiencing 12V battery issues so there's a halt on them and you can't purchase a replacement at the moment

And to add to the joy, replacement is $300 from GM (if you can get one), and it just fell out of warrantee last month.

I had to laugh and said 'poor GM, they've got battery problems all over', but unfortunately I foot the bill for the 12V (well I'd prefer that liability)

The 12v can be found anywhere. Excellent ones, better than stock, can be found at any auto supply company. And they can easily be put in by the consumer.
There are even lithium substitutes that think the duty is extra light (they have their own Battery Management System and need only the original 12v connection).

 

OEM, original equipment 12V batteries are 2-4 year propositions in practically any car. At 5 years, you're living on the edge (hello...with an early 2017). Though with AGM and some other specialty batteries the life can be longer. The Prius and Volt use a strange, small size in a hard-to-access location under the trunk floor. But in the Bolt it's right up front where you can grab it. So what's the problem?

Here's the problem: nobody else seems to have a 12V battery for a Bolt. It appears to be a AGM battery that ordinary auto parts places don't carry. See: 17 2017 Chevrolet Bolt EV Battery - Body Electrical - AC Delco - PartsGeek

IF you can find an auto parts place (or even Walmart, though they drew a blank online) that has the Bolt battery, you can probably save a lot of money compared to the dealer doing it. You just have to remember a few details, the main one being: be sure everything is OFF, including all accessories (turn the car off, then open the driver's door, at least), before starting the job.

OnStar apparently has its own backup battery, that's triggered if the car loses 12V power while the main power is on. If OnStar triggers its backup, it will drain its battery regardless of whether and when the car power comes back on, and it's non-rechargeable so you'll have to pay the dealer to install a new one. The procedure for disconnecting and removing the 12V battery, in the service manuals, intended to deal with that.

Many shops and battery places, like AAA, now have little portable batteries that they hook up to your car before disconnecting the 12V for replacement. It isn't enough to start the car, but it's enough to keep the base power alive so you don't lose radio settings and the like.

Some "battery minders" don't work well with AGM batteries; the voltages are different. Though the one I have works fine on the Prius. Worth trying, but don't expect wonders.

 

OEM, original equipment 12V batteries are 2-4 year propositions in practically any car. At 5 years, you're living on the edge (hello...with an early 2017).

That's true for ICE cars, but I imagine EV batteries are more like UPS batteries where they get very light use. In a walkthrough video I watched back in 2017 a GM guy was asked about the 12V, he said its very lightly used and I think he seemed to think it should last practically forever. Given that GM has no stock of them, and told the dealer they're seeing Bolt 12V's go belly up in quantity, it appears they're surprised too. If you consider that other EV's are also seeing 12V issues, I think the problem is that we build 12V's for ICE, not for EV's which is a very different use model.

For example, my UPS deep cycles the battery for conditioning, I doubt EV's do that and AFAIK lead acid like deep cycling.

By the way, we don't drive much (especially the last two years!) so the car only has 35k miles, so it's been very lightly used.

 

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Mine died after 4 years, and it was giving me Unable To Charge messages intermittently The dealer checked the codes when I took it in for the recall software update and they saw low voltage warnings. I was unable to find an aftermarket AGM, and had to get it through the dealer. Came with 3 year replacement warranty.

 

We've had issues with the 12V battery for a year or two with our 2017. Several times there wasn't sufficient power to sufficiently boot the car for startup. But then after charging it a bit it would be fine (either through driving or a jump start). The dealership said it was fine, and for a while I thought that the problem was related to an odd bad habit I had of turning the car off without having it in park (we thought that there might be a bug where something gets left on accidentally).

Anyhow this week it got really stuck while at the grocery store. I was able to jump and get it home, but then it developed a dummy warning light stuck on, and OnStar said there was a flag for the "Drive train control unit anomaly". Dealer decided it was the 12V, and called up Chevrolet to get a new one only to find .... wait for it ....

Other Bolts are experiencing 12V battery issues so there's a halt on them and you can't purchase a replacement at the moment

And to add to the joy, replacement is $300 from GM (if you can get one), and it just fell out of warrantee last month.

I had to laugh and said 'poor GM, they've got battery problems all over', but unfortunately I foot the bill for the 12V (well I'd prefer that liability)

I have a 2013 smart ED with the original 12 volt battery still working fine. This car is left plugged in unless being used. I suspect this keeps a trickle charge on it. I try to leave the bolt plugged in as well. It I s annoying I have to leave it outside, but am able to charge either in or out as we have three charging stations in different locations.

Have you left your Bolt plugged in when not in use, or just when charging?

 

Have you left your Bolt plugged in when not in use, or just when charging?

I prefer plugged in when not in use where safe to do so. My Bolt is not used regularly.

According to this post when the vehicle is plugged in, "Battery Maintenance Mode" provides
-more frequent checking (every 6 hours) of the 12V battery as opposed to 4 days if vehicle is left unplugged
-longer 2-3 hour period of maintenance charge as opposed to 45-90 minutes unplugged
-less restrictive threshold of 12V resting voltage for maintenance charge to kick in

 

If my 12V goes I'll probably buy a LiFePo4 replacement. In theory it could last longer.

I've never had much luck with the OEM batteries I've owned on new cars and trucks.

 

If my 12V goes I'll probably buy a LiFePo4 replacement....

Only the APM that provides the 12V bus when the car is powered up has a de-sulfation cycle where small AC bursts go to just the 12V battery to improve its life.
This AC may play hill with the 12V LiPo's built in BMS. And what about really cold temps some of us have?
How are factory cars dealing with really cold weather with a LiPo?

 

I bought a LiFePO battery for one of my motorcycles in 2011. I never put it on a tender, and as my health declined I rarely rode that bike. Sitting is usually deadly for AGM batteries, but the LiFePO didn’t lose charge while parked so that is less of an issue. It was still going strong when I sold the bike in 2019. They really are great, but weird. In cold weather they need load to warm them up before they give full voltage. Would this cause havoc in the Bolt? I don’t know.

 

Maybe, I have read about cold weather charging for things like heavy use deep cycle camper/rv use.
The Bolt has such minimal current load I doubt it can get that depleted but the LiFePo4 can be used down to a much lower voltage. Some sites claim 2 to 4 times the use over lead acid. Like a 50ah is 100ah lead.
BMW has been installing them in some of their models so I'd think we'd have heard something.

 

Mine was made in Germany... GM shipped a lead brick from Germany for these cars.

 

Been talking to the dealer - stock is out everywhere, all suppliers GM and off brand don't have it. And in the meantime, he said another Bolt came in this morning with the same problem. He's doing some research to see if a different battery will work, maybe a slightly bigger one. Don't know what people are going to do, we have a second ICE car until we can replace it with a suitable BEV, but it's been a problem with the Bolt down. Really been missing that little zip mobile.

EDIT: Lucky us, he found what he thinks is the last off brand battery on the West Coast. Car will be ready today.

This has been so odd, we're used to the Bolt just working. Not having to worry about gassing it up (we've been hitting the pump with the ICE van!), brakes, oil or the inevitable take it in and find something leaking ...

 

I had mine replaced for free under the previous software "fix" - one of the conditions was if the 12v was not to their spec, they would replace it before doing the software update. My dealer did it reverse and updated the software then gave me the replacement 12v, but I should be good for another few years at least. Maybe then we'll get a good quality lithium model.

 

How about a rebuilt battery? I would go with this in a heartbeat, if ours went bad. The Bolt is our only car.

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Have never understood why the OEM's don't just draw literally a few amps from the huge traction batteries through a stepdown circuit to provide 14.6v DC to the car? What is the down side?

 

You have to boot the electronics first before that. Kind of like needing a BIOS to boot the main computer, it's a - literally called - bootstrapping problem. Electrically there's other issues too, best way to think of it probably is the 12V is a buffer.

 

^ A simple tap off four of the traction batt cells will give you the 12-14v needed to boot the system and activate the electronic buck converter for the main 12V power.

 

The OEMs are online at everywhere I looked.

The Bolt and no car that I've ever heard of has high frequency charging.

 

Got it back with a Napa Autoparts Bolt battery. Can't tell you how nice it is to have her back and with confidence these odd startup problems are (I hope) finally solved. Didn't realize how much I've come to depend on the EV just always working, like any other electrical appliance. I laugh at how apparently traumatic this has been, remembering to the bad old days and the constant problems with our ICE cars (oil, brakes, leaks, head gaskets, starter motors, BATTERIES, plugs, and so on).

But the settings reset, and of course the mechanic didn't think to turn the hill top reserve back on The front office guy we worked with - who was really good, did say they're ready for working on the recalled traction batteries.

 

I used those pulse desulfator battery minders on my van and on my mom's battery backup sump pump. On the sump pump one of the diodes on the pump/charger control board burned out and I had to replace it. Luckily I'm able to diagnose and fix such things otherwise she would have been out the cost and hassle of buying a new backup sump system. The repaired system has been working for probably 8-10 years with no issues.

On my van the battery current sensor went out, so the van would report charging and battery problems. This is a little sensor on the negative battery cable that goes around a shunt and allows the computer to monitor current draw. This was potted and had tiny surface mount components and I was not able to diagnose and repair it. $102.22 for a replacement sensor.

Could be two unrelated failures. But both occurred on setups where I was using a pulse desulfator. I'll no longer use them on an active system. I'd maybe use it on a battery that is out of a system and you are stand alone charging and trying to desulfate knowing that it might damage the charger. But I'll never use one permanently attached to a vehicle or other battery system as I believe the pulses eventually kill diodes and break things.

And despite the desulfator being hooked up, I did not get any longer battery life from either battery.

 

^ I've never had any decent results using the Battery Tender trickle-Desuflators on my boat or Jetski led/acid batts either. I now make my own batteries for both from Headway LifePO4 cells plus BMS and the results have been excellent especially considering I no longer need to trickle charge the batts between weekends and they are one third the weight of the led/acid relics they replaced.

 

Would be kinda nice to push start the Bolt.

 

Would be kinda nice to push start the Bolt.

What? Why? These days, you can't even push-start something with a stick - or at least it's strongly dis-recommended. The last automatic I drove that had instructions for push-starting was a '57 Chevy with a Powerglide.

 

I think the Fords that had a rear transmission pump could be push started. I can push start my 2008 Corvette to start it well maybe 3 people or me downhill.
Might have to. Second battery went dead. Of course the OEM went early. Where did I put that receipt for second?

 

"1975 Subaru had an emergency starting crank"
I know some of the Asian products might be sold in some wild lands. Maybe it had it. I never saw one but I believe you.

 

My brother has a 2014 spark that he bought new with the original 12v battery. Only 38,000 miles on it.

 

Great now you've got me thinking about where I could add a second 12v battery to the car.