Chevy Bolt EV Forum banner

21 - 40 of 45 Posts

·
Registered
Joined
·
4,841 Posts
IMO ideally the car should allow for maximum flexibility for the driver/owner when it comes to charging and conditioning. If that were the case it would all but eliminate the need to "smart" EVSEs like the JuiceBox. I think GM should have given the Bolt an "advanced" menu where drivers could make settings like "always condition the battery when needed".
My friend in Albany would love that. He traded in his 2012 Leaf on a 2019 Bolt last month. The Bolt is using as much energy to warm the battery as he used for his commute. The Bolt has doubled his EV electrical use, blowing his net zero energy budget all to ****.

http://minerva.union.edu/willingp/EnergyBalanceFiles/cum17.gif
 

·
Registered
Joined
·
1,868 Posts
^ that sucks but it's also the reason the Bolt battery will probably last 3X as long as a Leaf battery.


Your friend just needs to add a few more PV panels to his system to make up for the Bolt.
 

·
Registered
Joined
·
1,106 Posts
^ that sucks but it's also the reason the Bolt battery will probably last 3X as long as a Leaf battery.
Is it bad for an EV battery to be cold or does it just not work nearly as well? I know that heat can damage a Lithium Ion battery but I didn't think that cold (outside of extreme cold that humans (even Minnesotans) rarely if ever experience would do any permanent harm.
 

·
Registered
Joined
·
1,106 Posts
My friend in Albany would love that. He traded in his 2012 Leaf on a 2019 Bolt last month. The Bolt is using as much energy to warm the battery as he used for his commute. The Bolt has doubled his EV electrical use, blowing his net zero energy budget all to ****.

http://minerva.union.edu/willingp/EnergyBalanceFiles/cum17.gif
Does he need to plug in every night to be able to get to work and back plus whatever margin for safety he's comfortable with? If not he can just plug in only when he needs to and the car won't use so much energy to keep the battery warm overnight. On a cold morning with a cold battery the Bolts range will be significantly reduced but it will still be better than a Leafs range.

He can also use settings like departure mode charging and telling the car that he's leaving a bit later than he actually is, this has the added advantage that whatever free warming he gets from the charge process will be maximized to benefit him when he leaves for work.
 

·
Registered
Joined
·
280 Posts

Attachments

·
Registered
Joined
·
4,841 Posts
Is it bad for an EV battery to be cold or does it just not work nearly as well? I know that heat can damage a Lithium Ion battery but I didn't think that cold (outside of extreme cold that humans (even Minnesotans) rarely if ever experience would do any permanent harm.
Lithium ion batteries must be above 32 F to charge at any useful rate.

https://relionbattery.com/blog/lithium-battery-cold-weather

https://batteryuniversity.com/learn/article/charging_at_high_and_low_temperatures
 

·
Registered
Joined
·
1,868 Posts
Is it bad for an EV battery to be cold or does it just not work nearly as well? I know that heat can damage a Lithium Ion battery but I didn't think that cold (outside of extreme cold that humans (even Minnesotans) rarely if ever experience would do any permanent harm.
IIRC there was a video posted by a really bright GM engineer, I believe he stated that you could literally freeze the main battery without damaging it. Of course it would be unusable in that state but you get the idea.
 

·
Registered
Joined
·
4,841 Posts
IIRC there was a video posted by a really bright GM engineer, I believe he stated that you could literally freeze the main battery without damaging it. Of course it would be unusable in that state but you get the idea.
Correct. Just don't try to charge it.
 

·
Registered
Joined
·
4,841 Posts
Does he need to plug in every night to be able to get to work and back plus whatever margin for safety he's comfortable with? If not he can just plug in only when he needs to and the car won't use so much energy to keep the battery warm overnight. On a cold morning with a cold battery the Bolts range will be significantly reduced but it will still be better than a Leafs range.

He can also use settings like departure mode charging and telling the car that he's leaving a bit later than he actually is, this has the added advantage that whatever free warming he gets from the charge process will be maximized to benefit him when he leaves for work.
Yes. He is experimenting to see what approach will use the least energy for battery heating.
 

·
Registered
Joined
·
4,551 Posts
Indeed charging will increase the temperature some but it may not be enough to get the battery to where the car wants it to be.
OK, so I guess the piece of the puzzle I wasn't considering must be that the car is more aggressive about keeping the battery warm when plugged in than when not. That would explain why it wouldn't have already warmed the battery before you started charging.
 

·
Registered
Joined
·
1,868 Posts
My friend in Albany would love that. He traded in his 2012 Leaf on a 2019 Bolt last month. The Bolt is using as much energy to warm the battery as he used for his commute. The Bolt has doubled his EV electrical use, blowing his net zero energy budget all to ****.

http://minerva.union.edu/willingp/EnergyBalanceFiles/cum17.gif
Keep in mind, that as soon as the coldest weather passes the Bolt battery conditioning/protection drops to almost nothing for the remaining months of the year, so he's seeing worst cast numbers right now.



Your friend consumed 7115 kWh and produced 7527 kWh, so he was ahead by 412 kWh production wise.... that might be just enough to make up for the Bolt conditioning/protection over the winter. He might still end up at or near net zero on his anniversary/settlement date.
 

·
Registered
Joined
·
4,841 Posts
Your friend consumed 7115 kWh and produced 7527 kWh, so he was ahead by 412 kWh production wise.... that might be just enough to make up for the Bolt conditioning/protection over the winter. He might still end up at or near net zero on his anniversary/settlement date.
My friend understands Jevons Paradox. Suggestions that he add more solar panels, or that the increase in usage won't eat up his production, don't change the fact of greater consumption. Surviving our dilemma depends on reducing consumption/CO2 production. Cooking the planet as efficiently as possible doesn't help.
 

·
Registered
Joined
·
1,106 Posts
OK, so I guess the piece of the puzzle I wasn't considering must be that the car is more aggressive about keeping the battery warm when plugged in than when not. That would explain why it wouldn't have already warmed the battery before you started charging.
All of my tests have involved battery cooling not heating but I suspect heating works the same way.

It seems the Bolt is very averse to use battery power to condition the battery. Likewise if you are charging it will give all the priority to charging the battery. It's only after a charge is complete (or if you plug in when a charge is not needed) does the Bolt feel free to use EVSE power to condition the battery.

My theory is that GM management (marketing types, not engineers) were worried that people would complain that the Bolt "lost range" while parked on very hot or cold days if the car conditioned the battery while parked so they directed the engineers to configure the BMS so that battery conditioning would (almost?) never occur when parked and not plugged in.

It is possible that there is some extreme threshold that will trigger battery conditioning from battery power but I haven't witnessed it and I've observed my battery get as hot as 37C.

@OP has a big advantage over us with a 2017 or 2018 Bolt because the target charge setting allows them to set the target charge to something below the current SoC so when they plug in a charge will not be needed and the car will start conditioning the battery immediately if it's warranted.
 

·
Registered
Joined
·
1,868 Posts
My friend understands Jevons Paradox. Suggestions that he add more solar panels, or that the increase in usage won't eat up his production, don't change the fact of greater consumption. Surviving our dilemma depends on reducing consumption/CO2 production. Cooking the planet as efficiently as possible doesn't help.
Not disputing the fact that there's a cost to protecting the Bolt's battery vs. not protecting it (Leaf). I guess the point I was trying to make was that if his goal was "net zero" for his electric bill... he may still hit it regardless of increased consumption. Once warmer weather arrives he'll be seeing up to 5mi/kWh from his Bolt like many of us do and that huge increase in efficiency and his historic PV overproduction may be enough to keep him near a $0 annual electric bill. Time will tell....
 

·
Registered
Joined
·
4,841 Posts
Once warmer weather arrives he'll be seeing up to 5mi/kWh from his Bolt like many of us do and that huge increase in efficiency and his historic PV overproduction may be enough to keep him near a $0 annual electric bill. Time will tell....
Yes. That is my guess. And since he measures everything, we will indeed see.
 

·
Registered
Joined
·
2,611 Posts
Keep in mind, that as soon as the coldest weather passes the Bolt battery conditioning/protection drops to almost nothing for the remaining months of the year, so he's seeing worst cast numbers right now.



Your friend consumed 7115 kWh and produced 7527 kWh, so he was ahead by 412 kWh production wise.... that might be just enough to make up for the Bolt conditioning/protection over the winter. He might still end up at or near net zero on his anniversary/settlement date.

"...his anniversary/settlement date."


Commonly called "True-Up".
 

·
Registered
Joined
·
8 Posts
The reason the JB lets you change the charge limit is to accommodate cars (like the 2017 and 2018 Bolt) that don't let you define a specific maximum charge level. If I wanted to charge to 75% (where I normally try to charge to) in my 2017 I can't control that with the car so I could tell the JuiceBox to stop charging at 75%.

Since you have a 2019 with the target charge setting on your car there's no reason to not tell JB to charge all the way, this will give all the control to the car which is what you want in your situation.

If the car is in control of the charge it's what decides to taper the charge near the end of the charge cycle (which will be dependent on whatever you have in your target charge setting), if you let JuiceBox do it the charge will cut off abruptly and you will not get the charge tapering and cell balancing cycle.

FYI, the "Hilltop Reserve" feature on the 2017 & 2018 Bolts is closer to 90% SoC than 95%, there seems to be some variance from car to car but usually my car will reach "full" on a Hilltop Reserve charge at 89%. I actually manually interrupt my charge at between 75% and 80% because I'm trying to preserve my battery capacity as much as possible for the long term and I only charge to "full" (about 89%) every 1000 miles or so just so my car can get the cell balancing effect. If I had the target charge setting I'd set it at 75% and leave it there unless I was going on a longer drive that required a fuller charge.
Do you think the BATTERY TEMP MANAGEMENT SYSTEM still works properly if you have the juicebox set to stop charging at 75% ?? I do the same thing, stop it at 75%, but my car sits in a hot garage in Phoenix AZ, and I often wonder if the CAR is EVEN ABLE TO RUN BATTERY COOLING because it can't get power, since the charging completely stops...Not sure if it's like a circuit breaker, and cuts power to the car completely.
 

·
Registered
Joined
·
8 Posts
IMO ideally the car should allow for maximum flexibility for the driver/owner when it comes to charging and conditioning. If that were the case it would all but eliminate the need to "smart" EVSEs like the JuiceBox. I think GM should have given the Bolt an "advanced" menu where drivers could make settings like "always condition the battery when needed".
So I got a new JB Pro 40 wifi and just did a test charge on my 2019 Premier. I do not do scheduled charging.

1) I believe the OEM EVSE charger tapers the charge at the end of the cycle. The JB Pro seems to go to the desired charge setting I make and then stop, no tapering of charging current.
Do I need to be concerned about this?

2) The app has a dial that you set for charging. I have to set current SOC on left side of screen and desired SOC on right side of screen. This seems very cumbersome. Is there an easier way to charge?
What happens if I just plug it in? I guess if the settings are not set it might do nothing at all. There is a setting for "Min Charge". Maybe I should just use that and set it to 57kW which will be nearly a full charge. Anyone using that setting for immediate charge?

3) I have my Infotainment charge setting to 95% which I think on earlier Bolts is the HillTop setting, I figure that 95% is 57kW. Presumably that setting is not applicable when using the JB. Is that correct?
I set the JB desired SOC to 57kW. When charging with the OEM EVSE that was a full charge (I think) and it reset the numbers on the Infotainment "Energy Information" "Energy Detail" back to 0. After my JB charge to 57kW those settings remain as they were before I charged. Is this because I did not charge to 100%? Is there something else I'm not doing right? There is a reset on a different screen, but it also resets a lot of other useful info. I don't recall doing that when charging with the EVSE charger.

4) When the charge was finished, OnStar started sending me alert notifications that charging was stopped due to an interruption. Well, yeah, charging was finished. The alerts just kept coming one after the other until I texted STOP and that apparently cancelled all On/Star notifications. So I guess I have something set up incorrectly here also. Any ideas?

I don't put on many miles in a day so it will be a few weeks before I use enough kW before I do my next charge.
Do you think the BATTERY TEMP MANAGEMENT SYSTEM still works properly if you have the juicebox set to stop charging at 75% ?? I stop it at 75%, but my car sits in a hot garage in Phoenix AZ, and I often wonder if the CAR is EVEN ABLE TO RUN BATTERY COOLING because it can't get power, since the charging completely stops...Not sure if it's like a circuit breaker, and cuts power to the car completely.
 

·
Registered
Joined
·
8 Posts
Is it bad for an EV battery to be cold or does it just not work nearly as well? I know that heat can damage a Lithium Ion battery but I didn't think that cold (outside of extreme cold that humans (even Minnesotans) rarely if ever experience would do any permanent harm.
Your sense of logic is the same as mine...Excessive HEAT can cause permanent damage, excessive COLD only probably only causes temporary loss of range. GM should allow more flexibility with charging options, or get the vehicle to analyze ALL potential climate problems. It should allow you to leave settings "idiot proof" if you want, or "allow adjustments" for those "non-idiots" ;-)
 
21 - 40 of 45 Posts
Top