[raitchison]

So I had the battery swapped on my 2017 earlier this week. Everything seemed to be going fine but I needed to charge this morning.

Based on other people's reports I knew that I had to re-enable Hill Top Reserve and that was literally the first thing I did before I even left the dealership parking lot.

Now I almost always use Departure Mode charging, both to minimize the amount of time my battery spends at high charge levels and also to make sure my battery is as cool as possible when charging. Since the recall was action I actually set Departure Mode to complete charging 2 hours after actually I actually planned to leave. This has been an easy and effective way for me to ensure I kept my battery charge below 80% while waiting for my new battery.

Well this time I have a new battery and I was planning a longer than normal drive todays so I decided to charge all the way to "full" (previously 89% with Hill Top Reserve enabled) so I told Departure Mode I was leaving 30 minutes before I planned to leave, wanted to make sure the charge and cell balancing would complete.

When I came out to my car at the normal time I expected the charge cycle to be complete but the green light was still blinking. Confused I fired up Torque and found that the (displayed) SoC was at 94% and it was still charging!

So I know there is some variance between different Bolts on what "full" is with Hill Top Reserve and I expected that my "full" set point might change with the new software but I've never heard of anything remotely as high as 94%

It sure seems that my car simply ignored the Hill Top Reserve setting (I verified it was still on) and decided to just charge all the way to 100%.

I'll do some more testing to verify this behavior but if this is true I am definitely going to take it back to the dealer. As it is even before the battery recall I only charged to "full" (89%) every 1000 miles or so and I NEVER charged to 100% (literally only happened once (by mistake) since I bought the car in 02/2018). As it is I find Hill Top Reserve to be insufficient as far as the ability to control the maximum SoC there's no way I'm going to accept only having the ability to trick Departure Mode and using manual intervention to control my charge.

BTW I had never had the 80% temp software loaded or any of the other recall related software installed before my battery replacement.

I did a search here for people with similar reports but I did not find any so I figured I'd post here FYI.

 

[martinknutson]

So I had the battery swapped on my 2017 earlier this week. Everything seemed to be going fine but I needed to charge this morning.

Based on other people's reports I knew that I had to re-enable Hill Top Reserve and that was literally the first thing I did before I even left the dealership parking lot.

Now I almost always use Departure Mode charging, both to minimize the amount of time my battery spends at high charge levels and also to make sure my battery is as cool as possible when charging. Since the recall was action I actually set Departure Mode to complete charging 2 hours after actually I actually planned to leave. This has been an easy and effective way for me to ensure I kept my battery charge below 80% while waiting for my new battery.

Well this time I have a new battery and I was planning a longer than normal drive todays so I decided to charge all the way to "full" (previously 89% with Hill Top Reserve enabled) so I told Departure Mode I was leaving 30 minutes before I planned to leave, wanted to make sure the charge and cell balancing would complete.

When I came out to my car at the normal time I expected the charge cycle to be complete but the green light was still blinking. Confused I fired up Torque and found that the (displayed) SoC was at 94% and it was still charging!

So I know there is some variance between different Bolts on what "full" is with Hill Top Reserve and I expected that my "full" set point might change with the new software but I've never heard of anything remotely as high as 94%

It sure seems that my car simply ignored the Hill Top Reserve setting (I verified it was still on) and decided to just charge all the way to 100%.

I'll do some more testing to verify this behavior but if this is true I am definitely going to take it back to the dealer. As it is even before the battery recall I only charged to "full" (89%) every 1000 miles or so and I NEVER charged to 100% (literally only happened once (by mistake) since I bought the car in 02/2018). As it is I find Hill Top Reserve to be insufficient as far as the ability to control the maximum SoC there's no way I'm going to accept only having the ability to trick Departure Mode and using manual intervention to control my charge.

BTW I had never had the 80% temp software loaded or any of the other recall related software installed before my battery replacement.

I did a search here for people with similar reports but I did not find any so I figured I'd post here FYI.

Do you use location based charging, or is hilltop reserve enabled everywhere? When my battery was replaced, my home location was cleared, and hilltop reserve ignored, as I use location based hilltop reserve.

 

[cfhgarza]

I also had to re-teach my home location

 

[raitchison]

Do you use location based charging, or is hilltop reserve enabled everywhere? When my battery was replaced, my home location was cleared, and hilltop reserve ignored, as I use location based hilltop reserve.

I don't use location based charging, I never have.

 

[jefro]

Then it should default to away???

 

[MichBolt]

I don't use location based charging, I never have.

I thought location based charging had to be turned on in order for departure mode to be available?

Can't switch to Departure charging mode

I'm trying to program times into my charging. When I get to the charging screen, it shows Immediate. The Departure side of the screen is dusky and it won't respond to me poking it. How can I fix this?

www.chevybolt.org

 

[BuckeyeBolt27]

My 2017 Bolt post-battery replacement just started ignoring hilltop reserve too. It was charging to the HTR limit the first few re-charges post-replacement, but suddenly started ignoring it and charging to 100%. All the settings look fine. Any updates on yours, raitchison?

 

[raitchison]

My 2017 Bolt post-battery replacement just started ignoring hilltop reserve too. It was charging to the HTR limit the first few re-charges post-replacement, but suddenly started ignoring it and charging to 100%. All the settings look fine. Any updates on yours, raitchison?

I only attempted to charge to "full" (with HTR) once since my original post (normally I do every ~1000 miles but I was taking a longer trip). On the advice of others I turned on location based charging and set my home location, as well as making sure that HTR was turned on. The setting was still ignored and it had charged to ~95% by the time I interrupted the charge. Interestingly, it seems to have started departure mode charging as if HTR is enabled. I had set my departure time about 30 minutes before I actually left, which means it was probably about 90% at the time I had departure mode set for.

Someone on the Bolt subreddit suggested I turn HTR off and back on again, which is my next thing to try before bringing it to the dealer.

I'm actually planning on taking the car on a trip to Vegas this weekend, which means I'll be charging my car to 100% for the second time since I've owned it, and the first time I've done so intentionally.

After that trip I'll turn HTR back on and see what it charges to.

 

[BuckeyeBolt27]

Someone on the Bolt subreddit suggested I turn HTR off and back on again, which is my next thing to try before bringing it to the dealer.

Yeah, I tried that too. Didn't make a difference. The weird thing about mine is that sometimes it stops at the HTR limit, sometimes it doesn't.

 

[raitchison]

@BuckeyeBolt27 FYI when I took my trip something else strange happened.

I had turned off HTR and set departure mode to finish charging at 7:00 a.m. Came out to my car at 7:30 and it was still charging! Fired up Torque and it showed that the SoC (DIC) was at 100% and the SoC (Raw) was at 99.9% but it was still charging at a full 16A (what I have my home EVSE limited to).

I waited another 10 minutes before I finally unplugged and stopped the charge.

Not sure what's going on exactly but I guess it's either that my BMS really has no idea what the capacity of my new battery is or the BMS is just borked and doesn't stop a charge no matter what. If it's the former issue a true 100% charge just might fix it but if it's the latter and I let it charge indefinitely the BMS just might charge the batteries above their rated voltage which would cause damage to them and could significantly reduce the useful life of my brand new battery.

 

[MichBolt]

@BuckeyeBolt27 FYI when I took my trip something else strange happened.

I had turned off HTR and set departure mode to finish charging at 7:00 a.m. Came out to my car at 7:30 and it was still charging! Fired up Torque and it showed that the SoC (DIC) was at 100% and the SoC (Raw) was at 99.9% but it was still charging at a full 16A (what I have my home EVSE limited to).

I waited another 10 minutes before I finally unplugged and stopped the charge.

Not sure what's going on exactly but I guess it's either that my BMS really has no idea what the capacity of my new battery is or the BMS is just borked and doesn't stop a charge no matter what. If it's the former issue a true 100% charge just might fix it but if it's the latter and I let it charge indefinitely the BMS just might charge the batteries above their rated voltage which would cause damage to them and could significantly reduce the useful life of my brand new battery.

Did you happen to see any individual cell voltages? 100% should be about 4.1667 V.

 

[raitchison]

Did you happen to see any individual cell voltages? 100% should be about 4.1667 V.

I looked and saw most of the cells were between 3.9-4.0V with a couple cells just above 4.0V. I do have the Torque logs but haven't downloaded them from my phone yet.

Is that 4.1667 the 100% (displayed) SoC or the 100% (raw) SoC?

 

[GJETSON]

Is that 4.1667 the 100% (displayed) SoC or the 100% (raw) SoC?

It is DIC 100%, as you can't charge to 100% Raw.

 

[BuckeyeBolt27]

@BuckeyeBolt27 FYI when I took my trip something else strange happened.

I had turned off HTR and set departure mode to finish charging at 7:00 a.m. Came out to my car at 7:30 and it was still charging! Fired up Torque and it showed that the SoC (DIC) was at 100% and the SoC (Raw) was at 99.9% but it was still charging at a full 16A (what I have my home EVSE limited to).

I waited another 10 minutes before I finally unplugged and stopped the charge.

Not sure what's going on exactly but I guess it's either that my BMS really has no idea what the capacity of my new battery is or the BMS is just borked and doesn't stop a charge no matter what. If it's the former issue a true 100% charge just might fix it but if it's the latter and I let it charge indefinitely the BMS just might charge the batteries above their rated voltage which would cause damage to them and could significantly reduce the useful life of my brand new battery.

Pre-battery replacement, the estimated charge completion time was quite accurate (within 30-60 mins). Post-battery replacement, I've noticed that it is wildly inaccurate (the car typically continues charging 2-4 hours after the estimated charge completion time reported on the dash).

Yesterday morning, it was supposed to stop charging at 5:00 am, but it was still charging at 6:30 am. When I entered the car, it said "Fully Charged" on the dash despite the green charging indicator still blinking and not solid yet.

 

[MichBolt]

Pre-battery replacement, the estimated charge completion time was quite accurate (within 30-60 mins). Post-battery replacement, I've noticed that it is wildly inaccurate (the car typically continues charging 2-4 hours after the estimated charge completion time reported on the dash).

Yesterday morning, it was supposed to stop charging at 5:00 am, but it was still charging at 6:30 am. When I entered the car, it said "Fully Charged" on the dash despite the green charging indicator still blinking and not solid yet.

Yeah, I think the BMS is still learning the actual battery capacity.

 

[Sean Nelson]

Yesterday morning, it was supposed to stop charging at 5:00 am, but it was still charging at 6:30 am. When I entered the car, it said "Fully Charged" on the dash despite the green charging indicator still blinking and not solid yet.

Some folks have speculated that the car's updated battery management system software does some more cell balancing and or condition checking after a full charge as an extra measure to detect any problems with the battery. I can see how that might lead to the green light still blinking, although if the cell voltages really are at 4.1667 then one wouldn't expect the car to be drawing very much current from the wall outlet.

If these sorts of things were happening to me then I'd be checking the voltages of all the cells via OBD.

 

[raitchison]

As a follow up I was due for a "full" charge again last week (I only charge to full every 1000 miles normally) and I am happy to report that this time the car did honor the Hill Top Reserve setting and stopped charging at 87% according to Torque.

This also means it's the first time my car has had a successful cell balancing cycle run on it since I got my new battery in February.

 

[BuckeyeBolt27]

Good to hear. My car still seems to be relearning the capacity as it'll keep charging 6-8 hours after it thought it should've been done. The math seems to check out that the estimated completion time and full bars represent the original battery capacity when in reality it's around 92% with the new battery and it takes that additional 6-8 hours on Level 1 to add the extra 8%. It's doing that to 100%, but not always with Hill Top Reserve enabled. Sometimes it will behave the same (continue charging for 6-8 hours, even showing all bars green with Hill Top Reserve on, then a few hours after unplugging the top 2 bars will be blank, showing SOC around 87% as expected), and sometimes it will stop close to its estimated completion time without illuminating all bars first. It's been a few thousand miles since the battery replacement, so I'd assumed it would've relearned the new capacity by now.