DC charging rate on the Bolt - Experiences?

[Pigwich]

So I think the Bolt isn't such a quick charger over CCS as we might have all hoped...

I plugged in my 55% charged Bolt today to a 50 KW fast charger, and it took it a full 32 minutes to bring the car up to 80%, which according to the machine, added 16 kwh to the pack. Now... I know that temperature and all that jazz are factors, but I get the feeling that it should have happened a little faster than this? I know when I'd plug my Spark in to the same charger, it would gulp down pretty close to the 50kw until it started to taper off when it got up to 80%. Today, like I said, I only took the Bolt up to 80% full, so it shouldn't have started to taper much. It just seems to be a little slower at the fast charger. Also, I was just coming off a long drive down a tall hill (a 20 mile, 5000 foot tall hill) but it was pretty cool up there, maybe in the low 50's. Hmmm...

I also sort of noticed that it was slow when I took delivery of it from the dealership. It had of course never been plugged in before, and they put it on their 50KW machine and it took 40+ minutes to put a hundred or whatever miles on it, and it was for sure not hot and definitely not even remotely close to fully charged. Not having any idea what the pack temperature was of course complicates this, but what are people experiencing with charging times on the DC fast chargers?

 

[like2bike]

Unfortunately, this charge rate is consistent with what others have seen. 70% SOC seems to be the end of the nice charge rate. Here is some data with a measured charge rate graph: http://boltev.blogspot.com/2017/01/dc-fast-charge-data.html

This data implies that a higher power (80 KW) L3 may only be faster up until 50% SOC?

 

[Zoomit]

Not all "50kW" chargers are made equal, some are 100A and some are 125A. Where did you charge? If there are pictures of that charger on PlugShare, we might be able to determine if it was capable of 100A or 125A.

Here's a graph I made that has a notional Bolt EV charging cycle in blue using a 125A DC fast charger that might be helpful.

 

[Pigwich]

The charger is one of the big EFACEC ones - 120 amps.

Any chance that graph was made with hilltop reserve turned on? I use hilltop reserve out of kindness to my pack, and it promptly let me know it was enabled when I plugged in the fast charger.

SO... who knows how this will work out when the bigger fast chargers come along. I assume the pack in the bolt is liquid cooled, right? I don't know enough about Li battery chemistry, but I know enough to know that determining SOC can be very tricky.

 

[Zoomit]

Under optimal conditions, that 120A charger should be able to charge a Bolt EV at about 46kW just before the taper begins.

Hilltop Reserve doesn't change how the car charges; it just stops the cycle around 87-90% SoC.