[bro1999]

So in the name of science (definitely not in the name of saving money) and because I seem to be a glutton for punishment, I decided to try yet another DCFC station in my area to see if I could have any better luck fast charging compared too my first 2 times.

This time, I went early in the morning after a night's sleep, with ambient temps in the mid 30's. In an attempt to heat the battery, I preconditioned the car for 10 minutes and during the whole 3.5 mile ride to the DCFC station (a 125A ABB unit), I pretty much bounced between 40-65 mph, flooring it to 65, then using the regen paddle to slow back down. The kW meter was ping-ponging readouts of 135 kW out to 70 kW in, so this surely had to heat the HV battery up. At no point did I see the battery conditioning % creep up from zero however.

START - SOC was 33% according to the station, 63 miles on the GOM.
5:24 min - 35%, 1.88 kWh delivered
11:22 - 39%, 4.19 kWh delivered, 24 kW
15:09 - 41%, 5.88 kWh delivered, 28 kW
20:15 - 45%, 8.62 kWh delivered, 35 kW
25:17 - 50%, 11.63 kWh delivered, 38 kW
26:55 - 52%, 12.73 kWh delivered, 40 kW (briefly hit 42 right after the photo)
28:10 - 53%, 13.57 kWh delivered, 36 kW
29:10 - 54%, 14.17 kWh delivered, 36 kW
30:05 (END charging) - 54%, 14.67 kWh delivered. (GOM ended at 100 miles)

So 14.67 kWh in 30 minutes. As the session cost me $10.95 total, that converts to 75 cents/kWh......

Since my Bolt did hit 42 kW before ramping back down, I don't think anything is wrong with it.
Is it an electron snob and doesn't like MD electrons compared to CA electrons? It is a CA Bolt.
Despite my attempts at heating the battery, perhaps the ambient temps (mid-upper 30's each of the 3 times) caused the battery temp to be at a less than optimal temperature?

I have to rule out the "these DCFC stations suck" theory, as I tested at 120-125A stations made by 3 separate manufacturers, and observed similar results at all 3.

Here's some shots of the DCFC display during my charging (first photo was actually taken 4 minutes after charging started):

 

[calebh2002]

Well, at least there is an improvement in your experience, however I'm not thrilled with what I have seen so far from owners DC experiences. I guess, with the hype leading up to deliveries I had a much higher expectation for DC charging after having seen the 80KW number thrown about a few times. In general though, this will not prevent me from buying a Bolt later this year when they arrive at Atlanta dealerships. It *might* however make my part time Uber driving a touch more difficult.

 

[ClarksonCote]

Could you read the battery voltage with something like a DashDAQ while this is taking place? It would be interesting if you could, as that would give you more insight into the limits. Battery Voltage * MaxCurrent of the station will be your rate until you start to taper at the top, unless the Bolt is limiting the input for some other reason (or you go to a high current station that doesn't exist yet in your area )

 

[Loboc]

DCFC is not high on my priority list. I'm considering a Bolt for my granddaughter's first car. A 100-mi effective radius is a good thing. Plus the low fuel costs and low maintenance costs would help.

Met a Solar City employee at the grocery store yesterday. Had an interesting little chat. He states that the 'lease follows the house not the owner' in their new agreements. I don't see how that's possible, but, checking it out anyway. Solar is becoming competitive with NG these days. I have noticed a couple Solar City installs recently in my area.

 

[saghost]

DCFC is not high on my priority list. I'm considering a Bolt for my granddaughter's first car. A 100-mi effective radius is a good thing. Plus the low fuel costs and low maintenance costs would help.

Met a Solar City employee at the grocery store yesterday. Had an interesting little chat. He states that the 'lease follows the house not the owner' in their new agreements. I don't see how that's possible, but, checking it out anyway. Solar is becoming competitive with NG these days. I have noticed a couple Solar City installs recently in my area.

Normally when you sell the house with the leased panels on it, you transfer the lease agreement to the new owner I believe - if you somehow got a buyer who refused to sign, Solar City would presumably have to come back and take the panels off if they couldn't make a deal.


(Not sure why anyone would refuse to take the deal, since in the out years the leases I've seen are just selling you the power at a lower rate than the utility and the panels are already installed.)

 

[Breezy]

2 out of 3 groundhogs are calling for an early spring. Hopefully you'll get a chance to try it in warmer weather soon.

 

[Norton]

1) This time, I went early in the morning after a night's sleep, with ambient temps in the mid 30's. ...

2)In an attempt to heat the battery, ...... At no point did I see the battery conditioning % creep up from zero however.

3)Since my Bolt did hit 42 kW before ramping back down, I don't think anything is wrong with it.

4)I have to rule out the "these DCFC stations suck" theory, as I tested at 120-125A stations made by 3 separate manufacturers, and observed similar results at all 3.

1) So it was not plugged in overnight, correct? Battery pack was not at a comfy temp, assumed.

2) Since the Bolt has a display for 'Battery Conditioning %" of energy usage, you should have seen some usage during this cold condition, correct? (As you know the Spark EV has the same 3 lines of '% of usage' display. Mine would have shown some usage.)

3) Say What??? Your Bolt has a problem. Maybe two or more.

A- It is not using a 50kW DCFC station as advertised. Others are getting the proper ~48kW when DCFC'ing, correct?

B- Your Bolt is never displaying "Battery Conditioning % of use" when it should be using power for this, correct?

C- Maybe your Battery TMS is not working at all. The limited charge rates are happening to protect your battery pack when it's this cold. That's good, right? But it should have thrown a code....

Good Luck walking into your local Chevy dealer, with you hat in your hands, with the first Bolt, with the first problem.
And it's a hard problem to prove. (2 problems, the way I see it.)
Hopefully your dealer has their required 50kW DCFC station up and running.

Also, a Service Writer's first job is to talk down to you and try to baffle you with BS. ( Almost as bad as salesmen )
You know you know more about the Bolt than he does, correct?

Again, Good Luck !!!

 

[ClarksonCote]

A- It is not using a 50kW DCFC station as advertised. Others are getting the proper ~48kW when DCFC'ing, correct?

It's not clear to me that this is true (for bro1999 or for others). bro1999 has been trying fast acceleration attempts to warm the battery but that may be working against him. Of course, I haven't followed all of his attempts, but that could be part of why his charging is limited. The battery doesn't like to be hot. In fact I would expect sufficient self warming when the battery is 30F for the charge rate to ramp up nicely.

If the car is driveable, there shouldn't be a need to warm the battery up to accept faster charge rates, it's only going to get warmer as it is charged anyway.

 

[Loboc]

bro1999 has been trying fast acceleration attempts to warm the battery but that may be working against him.
If the car is driveable, there shouldn't be a need to warm the battery up to accept faster charge rates, it's only going to get warmer as it is charged anyway.

I agree with this assessment. It may be that the battery is too hot, not too cold.

 

[Chris TX]

...

A- It is not using a 50kW DCFC station as advertised. Others are getting the proper ~48kW when DCFC'ing, correct?....

Where are you seeing this? BRo is showing the highest L3 charge rate I've seen on a Bolt. Have you seen higher? Why don't you think this is normal for the Bolt? Yes, it's very low for a just-released, super important BEV for GM, that won so many "awards", but yet it has one of the slowest L3 charging rates. Old Leafs can charge at a higher rate, and they have air cooled batteries!

There is a limitation being set by LG or GM, plain and simple. I'd be mad as hell to not get at least 50kW on those 50kW chargers. And yes, a 50kW L3 charger will deliver up to 50kW, sustained. I've done this with CHAdeMO on my Tesla and it stayed at 50kW for a long time.

I agree with this assessment. It may be that the battery is too hot, not too cold.

I also agree. No need to warm the battery, before charging. It will heat up, on its own by charging.

 

[BAZINGA]

Are these charging rates that enable long distance travel?

 

[jsmay311]

1) So it was not plugged in overnight, correct? Battery pack was not at a comfy temp, assumed.

2) Since the Bolt has a display for 'Battery Conditioning %" of energy usage, you should have seen some usage during this cold condition, correct? (As you know the Spark EV has the same 3 lines of '% of usage' display. Mine would have shown some usage.)

3) Say What??? Your Bolt has a problem. Maybe two or more.

A- It is not using a 50kW DCFC station as advertised. Others are getting the proper ~48kW when DCFC'ing, correct?

B- Your Bolt is never displaying "Battery Conditioning % of use" when it should be using power for this, correct?

C- Maybe your Battery TMS is not working at all. The limited charge rates are happening to protect your battery pack when it's this cold. That's good, right? But it should have thrown a code....

I look forward to Bro1999 answering some of these questions. But I'll try to address a few of them first.

1) Regardless of whether or not it was plugged in (you're not gonna go to a DCFC when it's already been charging overnight normally anyway), we don't know what the temperature targets are for the battery pack while charging on AC, L2, L1, etc., while plugged-in but not charging, while driving, etc., or how quickly/aggressively the battery heater tries to meet those temperature targets.

Based on these reports, it seems likely (or at least plausible) to me that the target temperature for peak DCFC performance is higher than the target temperature for driving. Either that or the battery heater is quite slow (either by design or by the heater being too small) in reaching those targets.

A- Bro stated that the DCFC unit was only rated for 125A. The max charge rate is dependent on the EVSE's max amperage and the battery pack's voltage. The Bolt's nominal pack voltage is 350V. At that voltage the max power from a 125A DCFC would be 43.75kW, not 50kW. And we also don't know at what point the Bolt's battery starts tapering the charge rate, which could explain any remaining difference.

C- You're right on one part: It should/would throw a code if the TMS was completely malfunctioning.

If the car is driveable, there shouldn't be a need to warm the battery up to accept faster charge rates

Anyone who's read any accounts of Teslas using Superchargers in cold temperatures know that that's far from correct. (The Bolt uses a different cell/chemistry than Teslas, so it's not apples to apples. Nevertheless, driving/discharging a battery is different than fast charging and we don't know yet exactly how GM's engineers decided to program charge rates vs pack temperature.)

 

[bro1999]

First time I tried DCFC the battery would have been sufficiently cool. It was sitting outside for a few hours in 30-40 degree temps before I drove slowly 4 miles to the EVgo station.

Never saw the battery conditioning energy usage move from 0% in any instance.

 

[Sean Nelson]

There is a limitation being set by LG or GM, plain and simple. I'd be mad as hell to not get at least 50kW on those 50kW chargers. And yes, a 50kW L3 charger will deliver up to 50kW, sustained. I've done this with CHAdeMO on my Tesla and it stayed at 50kW for a long time.

As jsmay311 pointed out, 50KW chargers are limited by current (amps), not power (kW). And at the charging voltages used by the Bolt, when the typical charger rated at 50KW reaches it's 125A current limit it's not delivering a full 50KW of power.

It will take a charger with higher than a 125A current limit before we know just how much DCFC power the Bolt can accept.

It seems pretty likely to me that GM has been very conservative in configuring the fast charging process to avoid harming the battery pack. It's a double edged sword because it means longer charging times, but I imagine that most owners would rather have a longer-lived battery considering that the vast majority of charging will be overnight at home anyway.

 

[jsmay311]

First time I tried DCFC the battery would have been sufficiently cool. It was sitting outside for a few hours in 30-40 degree temps before I drove slowly 4 miles to the EVgo station.

Never saw the battery conditioning energy usage move from 0% in any instance.

This would seem to indicate that the Bolt will only heat the battery when it's colder than 40F. (Did anyone ever determine at what pack temp the Volt starts using its battery heater?)

This would also gel with the observations that it takes quite a while for the Bolt to warm the battery during DCFC before it can accept peak charge rates, right?

 

[somms]

It seems pretty likely to me that GM has been very conservative in configuring the fast charging process to avoid harming the battery pack.

14 Spark EV charges at 48kW right up to 80%

Meanwhile the older Spark EV has no issue maintaining 48kW CCS charging also in a cold climate!?

Why would GM choose to now be conservative with the Bolt DC charging when they didn't on the Spark EV I wonder....hmmm

 

[bro1999]

This would seem to indicate that the Bolt will only heat the battery when it's colder than 40F. (Did anyone ever determine at what pack temp the Volt starts using its battery heater?)

This would also gel with the observations that it takes quite a while for the Bolt to warm the battery during DCFC before it can accept peak charge rates, right?

If I could get Torque Pro working with proper pids for the Bolt, I could monitor the pack temperature, but all I can get is the HV battery SOC% and 12V battery voltage. The Volt's pids don't work for battery temp, etc...

 

[Chris TX]

As jsmay311 pointed out, 50KW chargers are limited by current (amps), not power (kW). And at the charging voltages used by the Bolt, when the typical charger rated at 50KW reaches it's 125A current limit it's not delivering a full 50KW of power.

It will take a charger with higher than a 125A current limit before we know just how much DCFC power the Bolt can accept.

It seems pretty likely to me that GM has been very conservative in configuring the fast charging process to avoid harming the battery pack. It's a double edged sword because it means longer charging times, but I imagine that most owners would rather have a longer-lived battery considering that the vast majority of charging will be overnight at home anyway.

That doesn't explain the Bolt's fear of getting close to that 125A limit. On my Tesla, it will grab all it can if it can use it. It will peg that 50kW charger until it's at the end for the taper down.

 

[Norton]

...Meanwhile the older Spark EV has no issue maintaining 48kW CCS charging also in a cold climate!?

Why would GM choose to now be conservative with the Bolt DC charging when they didn't on the Spark EV I wonder....hmmm

But here's deal: That battery pack does not know it is in a cold climate. It is in an insulated case and when being driven or plugged in it should be in an ideal temp range. That is the job of having TMS. Hot or Cold.
(Leaf's don't have 'air cooled' packs. They have NO TMS, afaik. The pack just sits there and deals with life... or death....)

Now if the c̶a̶r̶ Chevy BEV is unplugged for X (?) amount of hours the pack will eventually start getting closer to outside air temps.
Then as soon as the car is powered up, (via a 'remote start' or just hoping in a cold car and driving it), the TMS should immediately start consuming power AND display that usage. (If available. Spark EV's and Bolt's do this.)

THIS is my personal sign to stop unplugging from a free public L2 at noon when I get the "charge completed" txt.
That first cold day when I see that "Battery Conditioning" has consumed 4%, or whatever, on my commute home,,,
THAT is when I plug in at work on L1 for the entire day, just for TMS reasons.

 

[PH2]

14 Spark EV charges at 48kW right up to 80%

Meanwhile the older Spark EV has no issue maintaining 48kW CCS charging also in a cold climate!?

Why would GM choose to now be conservative with the Bolt DC charging when they didn't on the Spark EV I wonder....hmmm

Spark EV = different battery pack configuration so it has a different voltage. Spark EV's battery from what I can find is 369V * 125A = 46.125kW; the peak voltage may be a little higher, or maybe there was some rounding to get to '48kW'.