Friday, January 6, 2017

DC Fast Charge data

I sat on the charger for 90 minutes tonight to get a better idea of the various tapers the car undergoes as it is charged. The main takeaway is that the tapers are not gradual, they are hard drops in charging power. The first drop I noticed was around 50% charge, then another around 70%, and then another around 80ish%. I ended up around 85% charged and pulling in around 16 kW at that time. Ambient temperature is around 60F.

There were two times once at 30% and once at 40% where some fans/pumps came on and drew around 5 kW from the charger for a few minutes. Other than that no real abnormalities in the charge.

Overall charge vs time

Charge rate vs SoC

Overall charge from 1-35%

Overall charge from 35%-68%

Overall charge from 68-87%

Tuesday, January 3, 2017

Another trip? Where to and what data should I collect?

Since I think I have nothing to do this weekend I figured I might drive somewhere again, maybe just a day trip to collect more data on charging, efficiency, etc. Any suggestions?

Monday, January 2, 2017

SF to LA: ECO Mode!

Headed back to LA today after a few days in SF. While I was there I was able to get a 100% charge at my buddies place and decided to see how far I could push the car on a single charge.

Initially my first stop was going to be in Selma which is around 190 miles from Oakland. I was unsure if I would actually make it that far and it was raining so I set the cruise control between 60 mph and 63 mph the entire trip. After going through two mountain passes and things flattened out I was doing really well with efficiency so I decided to push on to Vasila which was a total of 219 miles from my start.

I ended up making it with 4% SoC and the car just saying LOW for rated miles remaining, I was guess I had maybe 8-10 miles left though. Driving slow really upped the overall efficiency!!

Temp: ~45-50F
Speed: ~62mph
Wind: None
Cabin heat: Off
Miles: 219.2
Total kWh used: 57.6 (100%-4%)
Efficiency: 263 Wh/mi or 3.8 mi/kWh
Charging start: 1:35pm, 4% SoC
Charging finish: 2:25pm, 58% SoC (Also includes 2 minutes on the phone with EVgo)

After that I had a short trip to Bakersfield for another charge before going over the grapevine and getting back to LA. I tried to drive this as close to 75mph as I could.

Temp: ~50F
Speed: ~75
Wind: None
Cabin heat: Off
Miles: 84.8
Total kWh used: 25.8 (58%-15%)
Efficiency: 304 Wh/mi or 3.29 mi/kWh
Charging start: 3:48pm, 15% SoC
Charging finish: 4:30pm, 65% SoC (Total charge time was 39min)

Going up the grapevine chewed up a lot of range but going back down I was able to get a lot of regen.

Temp: ~55F
Speed: Mixed (~60ish going up the grapevine, 65-70 going down)
Wind: None
Cabin heat: Off
Miles: 106.9
Total kWh used: 25.8 (65%-22%)
Efficiency: 241 Wh/mi or 4.14 mi/kWh

Saturday, December 31, 2016

LA to SF: At the airport

Finally made it to SFO to pick up my friends with about 30 minutes to spare! The drive and charging took a lot longer than I had estimated but I think if I did not have the one leg with the bad weather it would have been a lot more reasonable.

Things I would take away from this:
- You cannot be in a hurry to take a long trip!
- Check the weather and wind before you leave and account for that
- Check the types of chargers you are going to be using; I assumed all EVgo put out 50 kW, but thats not the case
- If it's cold dress warm and use the seat heaters! Also precondition when you are hooked up to the charger!
- You will never get 50 kW out of the charger, I do not think I saw over 45 at any time even at low SoC

Stats for the final leg:
Temp: ~45-50F
Speed: 70 mph
Wind: None
Cabin heat: Off except for 5 minutes to clear the window once, two seat heaters on low
Miles: 134.4
Total kWh used: 40.2 (81%-14%)
Efficiency: 299 Wh/mi or 3.34 mi/kWh
Charging start: 6:29pm, 29mi range, 14% SoC
Charging finish: 7:04pm, 91mi range, 49% SoC (Also includes 2 minutes on the phone with EVgo)

Unplanned Stops: Thanks a lot heat and rain

Originally I had planned to go another 140 miles for the second leg of the trip but the weather had other ideas...

After I left the first charging stop it began to rain and continued to do so for the whole next leg of the trip. Being 45F outside and raining the windows quickly started to fog up so I was forced to use the heat in the car to keep everything safe. Needless to say this destroyed my range and reminded me why I wanted the 100 kWh battery in the Tesla. Previously I was managing around 275 Wh/mi and as soon as I turned the heat on it, coupled with the rain, jumped 375 Wh/mi. Based on this I would not make my next charger so I had to cut the trip short by around 30 miles and stop in Chowchilla to power up.

So far everything is working and the drives great but I can see how a 50 kW charging network will not allow for real long distance travel compared to the performance of a SuperCharger. Having to stop and charge for 1.5 hours each time really is not a viable thing unless you like sitting in Walmart parking lots. I could see how with SuperCharger like speed it might be passable though 30-45 minutes to wait is not that bad, time to maybe eat, walk the dogs, etc. I definitely do not see myself making this trip again!

Performance of this EVgo charger is also slower than my last stop, only pulling down 32 kW according to the car (100A, 366V according to the charger). The 30 minute time limit on the charger is also really annoying, this is something EVgo should look into removing!

New plan is to go another 120 miles and stop in Pleasanton for the final charge to get to SF. It stopped raining so hopefully the weather holds!!

Temp: ~45F
Speed: 65-70 mph
Wind: None
Cabin heat: On, 71F
Miles: 115.9
Total kWh used: 43.2 (83%-11%)
Efficiency: 372 Wh/mi or 2.69 mi/kWh
Charging start: 2:40pm, 19mi range, 11% SoC
Charging finish: 4:17pm, 139mi range, 81% SoC (Also includes 12 minutes on the phone with EVgo)

I left the last stop thinking I was good to go with 188 miles, little did I know the MIN was going to be more  inline with real performance!

Not my most efficient driving

Where my 50kW at?!

LA to SF: First stop

Took off from home this morning after topping up to 80% SoC (180mi range indicated). Also noted that as soon as you hit 80% the charger shuts off so if you want to try and ride the taper on the Level 3 charger I think you are out of luck. The battery was still charging at around 24 kW when it hit 80% as well. Oh well, I would have liked a few more miles in the battery. Update: I just realized it did not stop when it hit 80%, it stopped when it hit the 30min time limit. My actual SoC when I left was probably around 70-75%. I'll be more accurate on the next leg...

First stop is Delano CA at an EVgo station at a Walmart 140 miles from my start and I made it here with 14 (shows 18 but I was on the 14 mile side of the meter) miles of indicated range. Total battery use was 40.2 kW (75-8% SoC) which is ~287 Wh/mi or 3.48 mi/kWh. Speed was mainly set at the limit (65 or 70) but going up the grapevine really sapped my range although I did get back maybe 5-6 miles of range on the 5-6 mile downhill. It was also raining a bit so I am sure that did not help as well.

Overall the car is driving fine, lots of time in the right lane obeying the speed limit! The weather is pretty cold, around 45F, but I have the cabin heat off to save power. Much like your grandma's house you need to make sure to wear your sweater. It does start to beep at you around 30 or so miles of range left to stop and charge but it was not super annoying.

Charging now I am getting around 40-40 kW off the EVgo 50 kW charger, the car indicates a little more than an hour to hit 80% SoC and the charge session did stop after around 30 min. I spoke with EVgo and this is something programmed into the stations so if you want to charge more than 30min make sure to stick around your car to restart the session. The car does make some fan noise while the battery is charging but it is not too loud.

Time for the next leg...

Temp: ~45F
Wind: None
Cabin heat: Off
Miles: 140
Total kWh used: 40.2
Efficiency: 287 Wh/mi or 3.48 mi/kWh
Charging start: 11:22am, 18mi range, 8% SoC
Charging finish: 12:50pm, 187mi range, 83% SoC (Also includes three calls to EVgo to start charging sessions Update: Spent 6 minutes on the phone with EVgo)

Pre trip fast charge
Close to 80% and still pulling 23kW on initial charge
14-18 miles of range left at first stop 
Fast charging under way

Backup driver resting

Friday, December 30, 2016

First Impressions

Just got back home from picking up by Bolt, overall I think the car is pretty nice!

I do not have a problem with the seat comfort people mentioned in other threads, they feel pretty good to me. I am also not a big guy (5'10" 150 lbs) and not very wide, but for a skinny guy seem ok so far. Tomorrow I am going to spend 8 hours driving it so I will have a better impression of seat comfort after that.

In my opinion it rides pretty sporty and feels like a European car to me. Tight handling and very rigid. I like that kind of ride but on the 405 (which is like a washboard in a lot of places) there is a decent amount of bounce in the car. I was surprised with the handling though, I figured it would be more "American" and soft. It reminded me a little of the ride quality of the model X.

The dealer only had a charger capable of putting 3kw into the car so as soon as I had enough to get home I unplugged. I live next to a evGO station so when I got home I charged up for 20 min and it's pretty quick. Again taking it on a 8 hour trip tomorrow so I will be charging a few times and really see how it works out but overall it seems workable so far.

Everyone says it's cheap and plasticy, and it is, but I think it's the same style as my friends i3. His car is made of recycled soda bottles and because of that it's "eco" but still feels cheap. Overall very roomy and I think it's decent so far.

It's raining today so every time I tried to floor it at a stop light the just spun the tires but on the freeway it had decent pep. I think given that it is a $42k EV compared to a $170k Model X the performance is pretty good. More on this as I get a chance to really drive it.

The drivers display with the range and power being used I think is very intuitive. It's is a little strange that under around 65mph there is a green halo around your speed and above it starts to turn yellow, I guess they want to encourage you to drive slower and use less power. I didn't see if you go fast enough if it goes red but maybe tomorrow I will try to find out.  I do think there should be a reset for the setting of "power used since last FULL charge. I am not sure how chevy is managing the battery but this really encourages charging to 100% (which is a Tesla no-no) and there is no other way, that I can see, to reset this metric. Being a numbers guy this bugs me.

First fast charge!

The car app actually seems pretty useful to monitor charging status

Getting' some electrons

I think the orange looks cool