Chevy Bolt EV Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
149 Posts
Discussion Starter #1 (Edited)
Six months in, 13K miles. Had my first bit of trouble. A "Battery saver active" message appeared on the display several times throughout the day. The high voltage battery was well over half charged. Did not have a volt meter with me to check voltage of 12v battery. The only unusual item was that it was the hottest day of the year in Central CA, and I was running the air conditioner continuously for the first time. However the message continued to pop up later in the day after it had cooled off and AC was no longer in use.

Tried to diagnose via Onstar but was having difficulties that Onstar could not correct at the time. Can't get the car in to the dealer (Plan Z) for a few days. I noticed all the "Battery saver active" threads appear to be from 2017.

Checked 12v battery voltage this morning and it is 13.7v (car was plugged into 120v all night and shows a GOM of 100 miles). Fluid levels all good. I only drive the car on weekends, but will keep watch out next week for any recurrence. Just curious if you guys had any thoughts.
 

·
Registered
Joined
·
411 Posts
I'm also concerned about the 12v functioning of the Bolt. I recently got a little device that plugs into the "cigarette lighter" of the Bolt that constantly reads the functioning of the 12v system from Amazon (Palumma car charger). Very interesting to watch. It reveals a pattern of recharging the battery after a start to 14.9v for a few seconds, then settles down to about 12.6v after a minute. As the battery drops, you see the cars computer charger kicking in at 12.5 to bring the voltage back to 12.6. Any variation from the above pattern will be easily detectable, and will lead me to do a battery load test to check the integrity of the battery. (There is a separate thread on load testing the battery).

When you think about it, all of the cars' computer electronics and sensors are dependent on the good functioning of a lousy lead acid battery. It seems to me that insuring that it is in good shape is key to proper functioning of the Bolt.
 

·
Registered
Joined
·
149 Posts
Discussion Starter #3 (Edited)
When you think about it, all of the cars' computer electronics and sensors are dependent on the good functioning of a lousy lead acid battery. It seems to me that insuring that it is in good shape is key to proper functioning of the Bolt.
Yeah. As some likely know, Tesla's approach to that issue when they designed the Model 3 was to run more 12v systems off the traction battery via a DC-DC converter. The approach lessens dependence on the 12v battery and also allows for fewer charging/discharging cycles, thereby lengthening the life of the 12v battery.

PS - thanx for the tip on the 12v system reader. Will be ordering today.
 

·
Registered
Joined
·
2,374 Posts
I'm also concerned about the 12v functioning of the Bolt. I recently got a little device that plugs into the "cigarette lighter" of the Bolt that constantly reads the functioning of the 12v system from Amazon (Palumma car charger). Very interesting to watch. It reveals a pattern of recharging the battery after a start to 14.9v for a few seconds, then settles down to about 12.6v after a minute. As the battery drops, you see the cars computer charger kicking in at 12.5 to bring the voltage back to 12.6. Any variation from the above pattern will be easily detectable, and will lead me to do a battery load test to check the integrity of the battery. (There is a separate thread on load testing the battery).

When you think about it, all of the cars' computer electronics and sensors are dependent on the good functioning of a lousy lead acid battery. It seems to me that insuring that it is in good shape is key to proper functioning of the Bolt.

In 22 years of driving EVs, I've found that the 12V PbA auxiliary battery is *absolutely* the Achilles Heel of any EV that has one.
 

·
Registered
Joined
·
149 Posts
Discussion Starter #5 (Edited)
In 22 years of driving EVs, I've found that the 12V PbA auxiliary battery is *absolutely* the Achilles Heel of any EV that has one.

Two words: Super Capacitor.


As best I can make of the anecdotal evidence turning up, the issue seems quite simple; the DC-DC converter/charger cannot (or software will not allow it to) charge the 12v battery faster than its being drained.

----------------------

Anyway, just got off the phone with the dealer. The best info drawn from the phone call is that they have seen the error before.... it's always because the 12v was low ... and when charged it up all was OK.


As opposed to getting: "In each case it meant the 12v was dying and we replaced it under warranty."


In the latter case I would have made an appointment immediately. Given its the former, I will just drive the car awhile monitoring the low voltage system and see what happens.
 

·
Registered
Joined
·
2,374 Posts
Two words: Super Capacitor.


As best I can make of the anecdotal evidence turning up, the issue is as quite simple, as the DC-DC converter/charger cannot (or software will not allow) it to charge the 12v battery faster than its being drained.



----------------------

Anyway, just got off the phone with the dealer. The best info drawn from the phone call is that they have seen the error before.... it's always because the 12v was low ... and when charged it up all was OK.


As opposed to getting: "In each case it meant the 12v was dying and we replaced it under warranty."


In the latter case I would have made an appointment immediately. Give its the former, I will just drive the car awhile monitoring the low voltage system and see what happens.

Yup. The auxiliary battery doesn't need CCAs or a high capacity. It just needs a stable, high-enough voltage, under a small load.
 

·
Registered
Joined
·
2,374 Posts
Greg, I notice your sig line has you in EVs since the 90's. Is it fair to assume your first was an EV-1? Do you have a list of all the EVs you've owned posted somewhere?

Yup. Leased three of them. I've posted it before, but have no idea where. I'll do it again, and keep it in a text file this time...

1997 GM PbA EV-1. Leased from 1997-1998. Recalled (and kept by GM) for safety reasons. (One burned.)
1999 GM NiMH EV-1. Leased from 1999-2001.
1997(a) GM PbA EV-1. Leased from 2000-2002. (Recalled and refurbished 1997s were leased again.)
2001 Totota NiMH RAV4-EV. Bought new. Owned 'til 2011. Sold for $20k.
1999 Ford PbA Ranger EV. Bought in 2001 ($6k) off fleet lease. Owned 'til 2003, (PbA died). Sold for $6k.
2001 Derbi PbA E-GPR conversion. Conversion by Todd at Electric Motorsport of Oakland. Still own.
2011 Nissan LiIon Leaf. Bought new. Still own.
2011 Chevrolet LiIon Volt. Bought new. Still own.
2017 Chevrolet LiIon Bolt. Bought new. Still own.

I plan to keep adding to the list...:D
 

·
Registered
Joined
·
149 Posts
Discussion Starter #9
Yup. Leased three of them.
That is fantastic! You definitely have bragging rights. And THREE EV-1s. Interesting lineage in the details about those three cars.

Did you know that FF Coppola still has his EV-1?

Back when first got into EVs, when the Model 3 was announced, I read "The Car That Could" by Michael Shnayerson. He documented the development of the EV-1. What was interesting about the book was that it was published before GM stopped producing and started recalling. So, not politics. Just hard factual reporting.


[ame]https://www.amazon.com/Car-That-Could-Revolutionary-Electric/dp/067942105X/ref=sr_1_1?keywords=the+car+that+could&qid=1560277087&s=books&sr=1-1[/ame]
 

·
Registered
Joined
·
842 Posts
Yup. Leased three of them. I've posted it before, but have no idea where. I'll do it again, and keep it in a text file this time...

1997 GM PbA EV-1. Leased from 1997-1998. Recalled (and kept by GM) for safety reasons. (One burned.)
1999 GM NiMH EV-1. Leased from 1999-2001.
1997(a) GM PbA EV-1. Leased from 2000-2002. (Recalled and refurbished 1997s were leased again.)
2001 Totota NiMH RAV4-EV. Bought new. Owned 'til 2011. Sold for $20k.
1999 Ford PbA Ranger EV. Bought in 2001 ($6k) off fleet lease. Owned 'til 2003, (PbA died). Sold for $6k.
2001 Derbi PbA E-GPR conversion. Conversion by Todd at Electric Motorsport of Oakland. Still own.
2011 Nissan LiIon Leaf. Bought new. Still own.
2011 Chevrolet LiIon Volt. Bought new. Still own.
2017 Chevrolet LiIon Bolt. Bought new. Still own.

I plan to keep adding to the list...:D
Greg, any idea if you think you'll dabble on what VW is coming out with or maybe a Tesla?
 

·
Registered
Joined
·
2 Posts
To reopen the original discussion, I've been getting the "Battery Saver active" message on and off for the last couple of months on our 4 month old 2019 Bolt. It usually happens on longer (>90 mile each way) drives, when we have the kids in the car, AC on and they are using the USB ports for their devices. The only thing I can tell it seems to do is stop the USB ports charging as fast, although I couldn't tell at the time as the CarPlay functionality was still working - I only noticed after realising my phone wasn't charged when it should have been.

If it's a case of the DC-DC converter not being able to charge the battery enough, it seems like a fairly poor design as there wasn't really much additional battery load except radio, A/C and using 3 USB ports. Headlights were off, heated seats were off, heated wheel was off, all things which would add much more load one would think (A/C excepted although presumably that's run off the traction battery).

Could the 12V battery be going dead so early or is it only charged by the car once the voltage drops to 12V? I've checked the voltage and it seems fine. The other thing is I'm normally only using level 1 charging (120V) at home: I wonder if the 12V battery isn't topped up overnight in that case?

The warning is quite rare as I say, I'm just wondering if it's symptomatic of a weak/shorting cell in the battery. That aside, I love this car, it's one of the best cars I've ever owned. One pedal driving is so enjoyable!
 

·
Registered
Joined
·
3,682 Posts
The warning is quite rare as I say, I'm just wondering if it's symptomatic of a weak/shorting cell in the battery. That aside, I love this car, it's one of the best cars I've ever owned. One pedal driving is so enjoyable!
Yes. the DC-DC should easily keep up with all 12 volt loads. I would have an actual load test done on the 12 volt battery.
 

·
Registered
Joined
·
44 Posts
My experience has been the same, i.e. long trip, A/C on - the Battery Saver Alert popped up. The little bit of searching for added info I did indicated that the alert isn't unique to the Bolt. The warning is a feature of other GM cars. Assuming the DC-DC charging is sufficient, then perhaps a different battery would resolve the issue. Has anyone put in a new battery into their Bolt which then resolved the issue? BTW, the "feature" is designed to protect the battery - keep it from discharging to low.
 

·
Registered
Joined
·
332 Posts
Yeah. As some likely know, Tesla's approach to that issue when they designed the Model 3 was to run more 12v systems off the traction battery via a DC-DC converter. The approach lessens dependence on the 12v battery and also allows for fewer charging/discharging cycles, thereby lengthening the life of the 12v battery.

PS - thanx for the tip on the 12v system reader. Will be ordering today.
But... one thing that is not as well known about Teslas is that they won't charge the 12v battery if you run the HV battery very low. Bjorn Nyland showed that in one of his videos: he ran his HV battery down and then he couldn't hook it up to the charger because the 12v battery was dead and didn't have enough juice to open the charge door. Apparently it had stopped charging the 12v battery below about 20 miles remaining range so he ended up with both a dead HV and 12v battery.

Mike
 

·
Registered
Joined
·
842 Posts
I use both my USB ports on my 2019, which is about 11 months old right now ... 15,000 miles. One is for Android Auto - and charges my Note 9. The second one is just for charging/running a MiFi device that is in the car 24/7.
 

·
Registered
Joined
·
2 Posts
One more data point:

We went on a 'long' trip yesterday (100 miles each way, no chance for charging). On the way back, around 30% charge the battery saver active warning came on. We've not seen it since our previous long trip.

My suspicion is that this is nothing to worry about if it happens in this situation and the car is starting to attempt to reduce power usage when the main battery gets 'low', perhaps by not actively topping up the 12V battery? It would be nice to know definitively what is going on and what is actively being done to 'save' the 12V battery - if indeed it is the 12V battery being 'saved' in the case of the notification appearing in this scenario.

Note, it never happens any other time and the 12V battery always seems charged when I check it with my AGM battery charger. (I haven't yet done a load test however).
 
1 - 17 of 17 Posts
Top