[kendallg]

The range on my 2017 Bolt has been dropping over the last couple of months. Despite a lifetime average 5.1 mile/kWh, I went from getting 300+ miles of range after a full charge to 220, then 188, now around 130. The car hasn't shown a warning light or complained about anything. It's just displaying a range that should only belong in Alaska, driving on the freeway, uphill, with the heater on. Not in SoCal, where the car hasn't even seen a temp under 48 degrees.

I took the car into the dealership two weeks ago. They had it for two hours, tops, and said they did a software update for a known issue with the reporting. Tech said the range reporting should get back to normal after I drive a bit. At the time I was getting 188 miles from a full charge.

Fast forward two weeks, now getting 130 miles for a full charge despite having an average mile/kWh of 5.5 since the last dealer visit, I took the car back in. I ask the same tech if they checked the battery last time around, he answers that no. GM makes them apply any patches that are available and they can't dig any further. This time no call after two hours. The tech finally calls at 5pm and says they've got 8 codes that are popping up. I ask if they've checked the battery, no. Going to make them do that tomorrow.

So, here we are, waiting to hear back. At least they gave me a loaner, though driving around in a Trax is very hard for me to accept :laugh:

We'll see what tomorrow holds!

 

[surgeonFWW]

If you are getting 5.1 miles/kWh, that is GREAT (maybe even unreal and therefore unbelievable). If you are "spending" 5.5 kWh per mile, (60 kWh battery will take you 10.9 miles), that is HORRIBLY broken. It is way too scary to drive past that 130 miles to see if it is just a display problem, but you may not be truly that depleted. I hope your dealer has SOME experience with Bolt EV maintenance, cause none of the dealerships around my parts do. I would have to drive (or be flatbed-towed) 165 miles to Columbus to find experienced maintenance. Good luck and keep us posted.

 

[ZoomZoom]

If you are getting 5.1 miles/kWh, that is GREAT (maybe even unreal and therefore unbelievable). If you are "spending" 5.5 kWh per mile, (60 kWh battery will take you 10.9 miles), that is HORRIBLY broken. It is way too scary to drive past that 130 miles to see if it is just a display problem, but you may not be truly that depleted. I hope your dealer has SOME experience with Bolt EV maintenance, cause none of the dealerships around my parts do. I would have to drive (or be flatbed-towed) 165 miles to Columbus to find experienced maintenance. Good luck and keep us posted.

I can't even find a dealership that actually has a Bolt mechanic in my area. They say they do, until you press them or the parts guy takes you to the side and explains the real situation.

 

[kendallg]

If you are getting 5.1 miles/kWh, that is GREAT (maybe even unreal and therefore unbelievable). If you are "spending" 5.5 kWh per mile, (60 kWh battery will take you 10.9 miles), that is HORRIBLY broken.

I got a bit mixed up in what I was typing there! However, 5.1 miles/kWh IS the lifetime average of my car. I live in SoCal, have a 5 mile commute to work on surface streets and rarely have needed to use climate controls. This car has an easy life

 

[boltage]

Can you try to measure the battery capacity by this method:


1. Charge the car to full (100%) or hilltop reserve (87% or 88%, check the myChevrolet app after charging).
2. Drive for a while until it is less than half full.
3. Check the energy display for kWh used since the last charge (call this U).
4. Check the app for percentage remaining (divide by 100 and call it P; e.g. 34% becomes .34).
5. Calculate U / (1 - P) or U / (0.87 - P) (depending on if you used hilltop reserve; use the converted value from step 1).


The result of the calculation in step 5 is what capacity the battery is behaving like.

 

[JohnnyHo]

#MeToo and I also posted yesterday.

Max range at full charge ~200 miles running 4.96 mi/kWh. Note - new high voltage battery via GM recall Sept 2018. Hill top reserve is not on. I am in Texas at 85°, so no battery conditioning drain.

Data (same charge):
4/29/19 - Energy 4.5 kWh / distance 22.3 mi = 4.96 mi/kWh. Bolt instrument cluster Battery Gauge displays Max 174, probable 148 mi.
5/1/19 - Energy 9.2 kWh / distance 44.5 mi = 4.84 mi/kWh. Bolt instrument cluster Battery Gauge displays Max 155, probable 130 mi. Change of 22.2 mi traveled.


Wow 44.5 mi traveled and 76% battery remaining.. simple estimate at 4.84 mi/kWh = 38 of 60 kWh battery is usable.

 

[Vertiformed]

#MeToo and I also posted yesterday.

Max range at full charge ~200 miles running 4.96 mi/kWh. Note - new high voltage battery via GM recall Sept 2018. Hill top reserve is not on. I am in Texas at 85°, so no battery conditioning drain.

Data (same charge):
4/29/19 - Energy 4.5 kWh / distance 22.3 mi = 4.96 mi/kWh. Bolt instrument cluster Battery Gauge displays Max 174, probable 148 mi.
5/1/19 - Energy 9.2 kWh / distance 44.5 mi = 4.84 mi/kWh. Bolt instrument cluster Battery Gauge displays Max 155, probable 130 mi. Change of 22.2 mi traveled.


Wow 44.5 mi traveled and 76% battery remaining.. simple estimate at 4.84 mi/kWh = 38 of 60 kWh battery is usable.

This does indeed look worrying.

 

[kendallg]

Can you try to measure the battery capacity by this method:


1. Charge the car to full (100%) or hilltop reserve (87% or 88%, check the myChevrolet app after charging).
2. Drive for a while until it is less than half full.
3. Check the energy display for kWh used since the last charge (call this U).
4. Check the app for percentage remaining (divide by 100 and call it P; e.g. 34% becomes .34).
5. Calculate U / (1 - P) or U / (0.87 - P) (depending on if you used hilltop reserve; use the converted value from step 1).


The result of the calculation in step 5 is what capacity the battery is behaving like.

I must admit I didn't get to this level of analysis. What I did is observe the kWh that I got when charging to full and compared that to the battery charge that was display by the car.

Last time around, Friday, the car was 2 bars below 3/4 full. The "Full" charge added 10.16kWH. Simple math tells us that with a 60kWh battery, a quarter of that is 15kWh. 10.16 would only represent 16% of battery capacity.

Simplifying a little bit, there are 20 bars on the battery level display, so each bar represents about 5% of battery capacity. Based on that, with 7 bars gone, I should have needed to add 35% of the battery capacity or roughly 21kWh. Adding 10.16 means I'm only adding half.

This, of course, all supposes the data being presented is accurate. That may be the issue in the first place.

 

[boltage]

Data (same charge):
4/29/19 - Energy 4.5 kWh / distance 22.3 mi = 4.96 mi/kWh. Bolt instrument cluster Battery Gauge displays Max 174, probable 148 mi.
5/1/19 - Energy 9.2 kWh / distance 44.5 mi = 4.84 mi/kWh. Bolt instrument cluster Battery Gauge displays Max 155, probable 130 mi. Change of 22.2 mi traveled.

Wow 44.5 mi traveled and 76% battery remaining.. simple estimate at 4.84 mi/kWh = 38 of 60 kWh battery is usable.

Leaving out the miles per kWh, you used 9.2 kWh from full, leaving 76% of the battery capacity remaining. This is 100% - 76% = 24% = 0.24 of the battery capacity. 9.2 kWh / 0.24 = 38.3 kWh is what the battery capacity is acting like.

 

[boltage]

I must admit I didn't get to this level of analysis. What I did is observe the kWh that I got when charging to full and compared that to the battery charge that was display by the car.

Last time around, Friday, the car was 2 bars below 3/4 full. The "Full" charge added 10.16kWH. Simple math tells us that with a 60kWh battery, a quarter of that is 15kWh. 10.16 would only represent 16% of battery capacity.

Simplifying a little bit, there are 20 bars on the battery level display, so each bar represents about 5% of battery capacity. Based on that, with 7 bars gone, I should have needed to add 35% of the battery capacity or roughly 21kWh. Adding 10.16 means I'm only adding half.

This, of course, all supposes the data being presented is accurate. That may be the issue in the first place.

Note that the bars in the dash are "optimistic". I.e. two bars below 3/4 could mean any amount from 61% to 65%. You can see the remaining amount to the 1% resolution in the myChevrolet app.


However, regardless of that 5% versus 1% resolution, it looks like your battery is acting like it has much reduced capacity. 10.16 kWh / 0.35 = 29 kWh, and 10.16 kWh / 0.39 = 26 kWh. Also, it may be worse, if the way you measured the 10.16 kWh reports a higher number than what actually goes into the battery (since there are some losses between the wall and the battery).

 

[kendallg]

it looks like your battery is acting like it has much reduced capacity.

At this stage, that is the only thing regarding which I have any certainty I've pushed the guys to actually test the battery, I'm curious what I'll be hearing back.

 

[kendallg]

#MeToo and I also posted yesterday.

Max range at full charge ~200 miles running 4.96 mi/kWh. Note - new high voltage battery via GM recall Sept 2018. Hill top reserve is not on. I am in Texas at 85°, so no battery conditioning drain.

Data (same charge):
4/29/19 - Energy 4.5 kWh / distance 22.3 mi = 4.96 mi/kWh. Bolt instrument cluster Battery Gauge displays Max 174, probable 148 mi.
5/1/19 - Energy 9.2 kWh / distance 44.5 mi = 4.84 mi/kWh. Bolt instrument cluster Battery Gauge displays Max 155, probable 130 mi. Change of 22.2 mi traveled.


Wow 44.5 mi traveled and 76% battery remaining.. simple estimate at 4.84 mi/kWh = 38 of 60 kWh battery is usable.

If you're getting 200 miles of range at full charge you're well below what you should at an average of 4.96mi/kWh. That's for sure. Has there been an incremental drop in the full charge range? That's what I've seen with mine. Seems like the range drop on my car has been much more significant than yours, but maybe it's just the same problem on a different timeline. I did not get a new high voltage battery like you did so that's one variable to the equation.

 

[kendallg]

Alright, we have an update. After not hearing from Chevrolet yesterday they gave me a call a few minutes ago.

There is an issue with the Hybrid Power Control Module, though my advisor did not indicate exactly what issue. Apparently that part is on back order and he currently has no idea when they'll get it. Could be 2 days, 2 weeks, or more. According to him this is a known issue - so why did they not check for this when I brought the car in two weeks ago - which is contributing to the lengthy turnaround.

Fortunately, on Wednesday, I asked them for a loaner when I was only supposed to be given shuttle service. At least I have wheels, though they are petrol consuming wheels. Without expecting much I asked about them covering the gas costs as compensation for the fact that they couldn't give me an EV to use. That was declined

More later...

 

[GregBrew]

Alright, we have an update. After not hearing from Chevrolet yesterday they gave me a call a few minutes ago.

There is an issue with the Hybrid Power Control Module, though my advisor did not indicate exactly what issue. Apparently that part is on back order and he currently has no idea when they'll get it. Could be 2 days, 2 weeks, or more. According to him this is a known issue - so why did they not check for this when I brought the car in two weeks ago - which is contributing to the lengthy turnaround.

Fortunately, on Wednesday, I asked them for a loaner when I was only supposed to be given shuttle service. At least I have wheels, though they are petrol consuming wheels. Without expecting much I asked about them covering the gas costs as compensation for the fact that they couldn't give me an EV to use. That was declined

More later...

Yeah, I feel you. I got a brand-new, fully loaded Silverado pickup as a loaner when my '17 Bolt was in for some post-purchase work. I observed the gas gauge actually moving downward in my 20-mile freeway trip home. Forty miles of freeway driving cost me over $9. That was at $3/gal. It's now approaching $5/gal around here.

 

[kendallg]

Good luck and keep us posted.

Well, the latest is as follows. They received the new Hybrid Power Control Module on Thursday (that's 2 weeks to get the part) and told me I should be getting the car back late Friday or on Saturday.

They called back on Saturday to say that the computer could not connect with the new part. They are still working through this and have actually opened a case with GM. First time they've seen the issue that they're seeing on my car. Always good to be special, right?

Just for reference, this isn't a podunk dealership. They're the Chevy dealership for the west side of LA and had a large number of Bolts/Volts lined-up when I've dropped my car off for service. Just saying that it's not like they see one of these cars every month and, therefore, have zero understanding of how to work on them.

 

[JohnnyHo]

*** Duplicate post from the thread I started. ***

Problem Identified - Low Voltage Cell #83

:|No error codes. No OnStar warnings. Just diminished range that I noticed. 170 mi range instead of 238. This seems to be/might be a standard decrement if a single cell fails. In a similar situation (attached below), one cell failed and the battery went from 60 kWh to 35 kWh which is very close to my calculated 38 kWh capacity. Note: Poster used a 3rd party tool to gather battery information.

Warning - my local dealer told me many times over 2 weeks that my battery was fine. I pressed for an answer why my range was low with high efficiency ~5 mi/kWh.. They kept saying driving habits vary, your battery is fully charged. You must force them to review the HV battery efficiency, kWh used and remaining battery life.

A very similar situation is detailed here..

 

[kendallg]

*** Duplicate post from the thread I started. ***

Problem Identified - Low Voltage Cell #83

:|No error codes. No OnStar warnings. Just diminished range that I noticed. 170 mi range instead of 238. This seems to be/might be a standard decrement if a single cell fails. In a similar situation (attached below), one cell failed and the battery went from 60 kWh to 35 kWh which is very close to my calculated 38 kWh capacity. Note: Poster used a 3rd party tool to gather battery information.

Warning - my local dealer told me many times over 2 weeks that my battery was fine. I pressed for an answer why my range was low with high efficiency ~5 mi/kWh.. They kept saying driving habits vary, your battery is fully charged. You must force them to review the HV battery efficiency, kWh used and remaining battery life.

A very similar situation is detailed here..

***duplicating from a post I made on your thread. I hadn't seen your response here***
Have you had them check the Hybrid Power Control module?

The symptoms you're seeing sound extremely similar to the ones I had/have...

 

[JohnnyHo]

kendallg, yes, read your post and told service manager to check the Hybrid Power Control Module [aka? Battery Energy Control Module (BECM)).

Problem identified with GM engineer's assistance - one failed battery cell (not clear from service manager is this is a cell or a cell pack (3 cells). [***edit - Svc Mgr said, "Cell 83 read 4.7V, should be 5.5V." This makes no sense b/c each cell pack should be ~4V]

Ignorance abounds, not in a bad way, they are simply unfamiliar with EVs.

GM Service is single threaded. 1) check for error codes, 2) charge battery to full, 3) test drive... nothing wrong. They can't understand what I am telling them about battery capacity diminished to 75% after 9 kWh consumed.... simple math is a challenging way to communicate and the fact that it's electrical only complicates things.

Battery Information - Sorry, TMI for many
350.4V (nominal)
- 5 sections [1 & 3 same PN, 2 is flipped different PN, 4/5 different PN (narrower)]
- 10 modules (2 per section wired in series)
- Cell Pack is ~4V (3 battery cells wired in parallel) 96 cell packs
- Battery cells (3 per cell pack = 288 battery cells)

57.02 kWh battery not 60 kWh (LG specs on modules):
- 8 modules x 5.94 kWh = 47.52 kWh
- 2 modules at 4.75 kWh = 9.5 kWh

Yes, can replace RESS (Rechargeable Energy Storage System) (entire battery)
Yes, can replace a section (5 total)
??? replace module (10 total – 2 per section)
Can’t replace cell pack (96 cell packs - 3 battery cells sandwiched together)
Can’t replace single cell (288 total battery cells)

 

[GJETSON]

Problem identified with GM engineers assistance - one failed battery cell (not clear from service manager is this is a cell or a cell pack (3 cells).

It is likely a single cell in cell pack #83 . There would be no way of knowing without physically drilling out the spot welds on the tabs connecting those three cells. The difference between a single large cell, and three smaller ones connected in parallel is basically meaningless in this instance. It is only a packaging decision.

 

[kendallg]

GM Service is single threaded. 1) check for error codes, 2) charge battery to full, 3) test drive... nothing wrong. They can't understand what I am telling them about battery capacity diminished to 75% after 9 kWh consumed.... simple math is a challenging way to communicate and the fact that it's electrical only complicates things.

The service definitely needs to adapt quicker to EVs. The first time I brought the car in for my range issues the service advisor asked if I'd like to get an il change done while it was there...During that visit they didn't look any further than pushing two software updates that GM had released. It must be said that though some issues with the service are EV related, some are just GM related...