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Discussion Starter #1
As mentioned in a prior post, I will be backpacking out of the Ansel Adams Wilderness, near Lee Vining this weekend. I did a similar drive last year, but that was before the Bridgeport EA station came online, and also before Yosemite started restricting driving through (reservations required).

The easy way to go is via Sacramento, US-50 and Gardnerville, NV. It's an extra 55 miles of driving (55 minutes per Google), but there are lots of charging stations up to Gardnerville, so no need to worry/hypermile.

The other option I'm looking at is Oakdale, CA-108 over Sonora Pass. I can get to Oakdale with 55%, charge for ~50 minutes to 90%, and then I have 130 miles and 7,000 feet net gain (pass is at 9,600 feet) to reach Bridgeport. I think that'll require ~75% charge (10kWh for the elevation, 35kWh for the distance). But of course if I'm wrong, it'll be a problem since there is zero infrastructure for the last 50 miles of the route.

(I think for the return, Sonora Pass is a no-brainer since that's 7,000 feet of net elevation loss.)

Interestingly, this route has even less charger coverage for Tesla - Manteca or Groveland on one end, Topaz Lake or Mammoth on the other - but with 330 miles of range, you could go direct without re-charging at all.

What do you all think?
 

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I think it really depends on your preferences. For me, on road trips, I typically like to take different routes to and from (that let's me do the most exploring and see the most sites), so I'd probably go US-50 up and CA-108 back. Even without that, if your comfort level requires charging to 90% for the trip up CA-108, I'd suggest US-50 instead. Even if it represents more time over all, most of that additional time is driving, not charging.

I guess the other consideration is the Governor's recent orders. I know a number of small communities in the Eastern Sierras are really not happy about outside visitors at this point, so is it possible travel on CA-108 could be restricted?
 

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Discussion Starter #3
I think it really depends on your preferences. For me, on road trips, I typically like to take different routes to and from (that let's me do the most exploring and see the most sites), so I'd probably go US-50 up and CA-108 back. Even without that, if your comfort level requires charging to 90% for the trip up CA-108, I'd suggest US-50 instead. Even if it represents more time over all, most of that additional time is driving, not charging.
I'm of the same school of though in general. However, the drive up will be pretty much all in the dark, so honestly I'm just looking to minimize time/headache.

I guess the other consideration is the Governor's recent orders. I know a number of small communities in the Eastern Sierras are really not happy about outside visitors at this point, so is it possible travel on CA-108 could be restricted?
I've not heard anything yet, though I'll keep an ear out. It's ironic that back in March when the risk was very low, they shut everything down and now that the risk is much higher, most things are still open. Maybe if they'd been more thorough then, we wouldn't be in this mess.
 

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I'm of the same school of though in general. However, the drive up will be pretty much all in the dark, so honestly I'm just looking to minimize time/headache.

I've not heard anything yet, though I'll keep an ear out. It's ironic that back in March when the risk was very low, they shut everything down and now that the risk is much higher, most things are still open. Maybe if they'd been more thorough then, we wouldn't be in this mess.
I was considering the same thing when I was looking forward to a trip up CA-120 (before all this stuff started happening). Basically, I was planning for the return trip down CA-120 because it would be better lit with the sun at my back.
 

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Discussion Starter #5
Worked out pretty well. I did the same route out and back over Sonora Pass (decided Tahoe was too long a detour). In total I spent ~2h25 charging, at the Oakdale and Bridgeport DCFCs both on the way out and back. I had no charging difficulties. I drove more conservatively than usual and never dropped below 35% charge, except on the very last leg going home. My concerns about range over the pass were not realized. I expected to see better efficiency going westbound over Sonora Pass (vs. eastbound) but on the whole I don't think there was a big difference. I guess both sides are fairly steep.

I really like Bridgeport as an EA location. It's a pleasant small town - walkable, scenic and fortunately when I went through not too hot. The gas station with the DCFC installation has some tables outside to sit at, if one prefers to use the time for lunch. The Oakdale DCFC is just okay - functional (though one charger has been out for months) but not my favorite. The town is just too spread out and too hot in the summer. It'd be awesome of Groveland's DCFC finally opened, or if Sonora got one.

When I was coming back through Bridgeport, I was annoyed to see a Tesla parked in the middle DCFC, not charging. Eventually I noticed it had a very flat tire. Still not great behavior, but I guess the tow truck is more to blame than the (clueless) owner. I did not see anybody else charging while I was in Bridgeport.

Here's the breakdown of the trip:
  • 0 miles, 100% charge - left San Mateo
  • 115 miles, 61% charge - arrived Oakdale
  • 115 miles, 86% charge - left Oakdale (ChargePoint DCFC, ~40 minutes)
  • 215 miles, 37% charge - crossed Sonora Pass
  • 250 miles, 35% charge - arrive Bridgeport
  • 250 miles, 83% charge - left Bridgeport (EA DCFC, ~55 minutes)
  • 285 miles, 65% charge - reached trailhead (south of Lee Vining)
  • 320 miles, 55% charge - arrived Bridgeport (returning)
  • 320 miles, 78% charge - left Bridgeport (EA DCFC, ~30 minutes)
  • 450 miles, 45% charge - arrived Oakdale
  • 450 miles, 67% charge - left Oakdale (ChargePoint DCFC, ~20 minutes)
  • 555 miles, 22% charge - reached San Mateo
 

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Sounds like the trip was pretty straightforward and uneventful (in a good way). I really like the Bridgeport location. I really think it's a glimpse at what the future of EV travel charger sites will look like, though with the pull-through gas pumps replaced with 350+ kW chargers.
 

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Discussion Starter #7
Sounds like the trip was pretty straightforward and uneventful (in a good way). I really like the Bridgeport location. I really think it's a glimpse at what the future of EV travel charger sites will look like, though with the pull-through gas pumps replaced with 350+ kW chargers.
That is something to look forward to. On balance, I think EV chargers tend to be better situated in small towns. The bigger the place, the more likely the DCFC is to be a long way from anywhere interesting (though there are notable exceptions - e.g. the EvGO in Visalia). Laytonville on US-101 is another good example, vs. Cloverdale or Windsor.

350kW would be nice of course, but even 150kW would more than suffice for me, and I daresay I travel more than many.
 

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That is something to look forward to. On balance, I think EV chargers tend to be better situated in small towns. The bigger the place, the more likely the DCFC is to be a long way from anywhere interesting (though there are notable exceptions - e.g. the EvGO in Visalia). Laytonville on US-101 is another good example, vs. Cloverdale or Windsor.

350kW would be nice of course, but even 150kW would more than suffice for me, and I daresay I travel more than many.
I still have to check out the Laytonville charger. I drove through there in my Bolt EV long before there was a charger there (coming down out of the mountains above Covelo). It would have been a decent first charging stop, too. Overall, I agree about the small-town charging stops. The chargers tend to be located in business districts, where a number of options are available. The EVgo charger at Black Bear Diner in Willows (off I-5) is a perfect example. You're a 5-minute walk or less from at least a half dozen restaurants, coffee shops, convenience stores, etc.

Personally, I think that 150 kW is all that's really necessary for moderately efficient EVs (3.5 to 4.5 mi/kWh). At that point, it's more about the charging profile than the speed. Even the proponents of the Tesla-style 15-minute charge stops would be accommodated by a 150 kW flat charging curve. You'd add about 150 miles in a 15 minute stop and be back on your way. For those of us who choose to take longer breaks, you're adding around 300 to 350 miles of range in a 30 to 40 minute meal break.

The 350+ kW chargers will be necessary, but not for efficient passenger cars. At that point, it's more about trucks and large SUVs that will be towing heavy loads for long distances. Even on a 150 kW charger, GM's upcoming 200 kWh batteries would take over an hour to charge to 80%, and that's maybe only 150 to 200 miles of range when towing a heavy trailer.
 

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Eric, what are the real-world charging speed differences (all else being equal) between a 62.5kW, 150kW and 350kW fast-charger in 2017~2019 Bolts? Say, to go from around 20% to 70%, what's your best guesstimate from your limited (😈) experience?

Thanks!

Rich
 

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Eric, what are the real-world charging speed differences (all else being equal) between a 62.5kW, 150kW and 350kW fast-charger in 2017~2019 Bolts? Say, to go from around 20% to 70%, what's your best guesstimate from your limited (😈) experience?

Thanks!

Rich
I know it's not exact, but I just approximately 10 minutes difference between charger levels. For the Bolt EV, after 150 A of charging current, the charger speed doesn't really matter because the car itself becomes the bottleneck. Another issue is that both 125 A and 150 A chargers can be listed as "62.5 kW" even though the latter can provide significantly more power. A basic breakdown I use is 60%, but 70% is also valid. Also, these are under ideal conditions that do not account for energy being directed to battery and cabin conditioning, which affect the slower chargers more before and after the initial step down.

For 100 A, "50 kW" chargers, the Bolt EV should go from 20% to 70% in about 50 minutes. Real-world with battery and cabin conditioning, that can take closer to an hour or more.

For 125 A, "62.5 kW" chargers, the Bolt EV should go from 20% to 70% in about 40 minutes. Real-world with battery and cabin conditioning, that can take closer to 45 to 50 minutes.

For 150 A and faster chargers (including 150 and 350 kW), the Bolt EV should go from 20% to 70% in about 33 minutes. Real-world with battery and cabin conditioning, it's typically closer to 35 to 40 minutes.

GM designed the Bolt EV fairly well for 125 A chargers because it will max out the charger up to 70% when battery and cabin conditioning are required. It's not unusual for me to still be drawing close to 44 kW at 65% battery (how I know it's still worth it to stay charging because the Bolt EV needs that extra energy for onboard systems. The 100 A chargers are under-powered for the Bolt EV, in my opinion, because even after the initial step down, the Bolt EV's systems will be drawing more power than the charger can provide, slowing the actual charge rate.

Here I go on the flat charging profile again, but this is one of the reasons I would be okay with the Bolt EV having a peak 55 kW charging rate if the charging profile was flat to 80-85%. At that point, a Bolt EV could charge from 10% to 80% over the course of a 40 to 45 minute stop. Basically, you could travel about 400 miles with one stop for a meal break while charging.
 

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Thanks Eric, that was helpful and useful info.

Eric, one other question. Is there a speed advantage in the Bolt to use the 350kW charger over the 150kW units?

Rich
 

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Thanks Eric, that was helpful and useful info.

Eric, one other question. Is there a speed advantage in the Bolt to use the 350kW charger over the 150kW units?

Rich
No. Right now, there's only one EV that sees a speed advantage from the 350 kW chargers (and that's the Porsche Taycan). The difference is really only for EVs with the 800 V architecture. For EVs with a 400 V to 500 V architecture, there's no real difference between the 150 kW and 350 kW chargers.
 

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The 150kW units max out at 300 amps and 500 volts. The 350 kW units max out at 350 amps and 1000 volts.

The Bolt charges at a max of 150 amps and about 360-370 volts. Both 150 and 300 kW units are far enough outside the Bolt's limits as to be indistinguishable.
 

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The 150kW units max out at 300 amps and 500 volts. The 350 kW units max out at 350 amps and 1000 volts.

The Bolt charges at a max of 150 amps and about 360-370 volts. Both 150 and 300 kW units are far enough outside the Bolt's limits as to be indistinguishable.
For obvious reasons, I haven't been able to test the available current myself to confirm, but according to the placards, both the 150 kW and the 350 kW chargers both provide 350 A. The difference is, the 350 kW charger will provide the full 350 A all the way up to 950 V. Depending on who is classifying the chargers, the 150 kW units EA is using could be rated as high as 175 kW or even 200 kW (Recargo lists their units as "200 kW," but as far as I know, they are also limited to the same 350 A at 500 V).
 

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Guess I've been taking the labels too literally. It's odd that they would under-advertise their capabilities, unless it is software limited to 300 amps but simpler for them to use 350 amp hardware. Or maybe it's as silly as 175 tested poorly as a marketing term compared to 150. Hopefully within a few years we'll have the capability to find out.
 

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Guess I've been taking the labels too literally. It's odd that they would under-advertise their capabilities, unless it is software limited to 300 amps but simpler for them to use 350 amp hardware. Or maybe it's as silly as 175 tested poorly as a marketing term compared to 150. Hopefully within a few years we'll have the capability to find out.
Technically, we already know. The Audi e-tron is a 400 V architecture vehicle, so in order for it to charge at 150 kW on Electrify America chargers (which it does), it must be receiving 350 A. My guess is that Electrify America wanted to avoid the trap that other charging providers fell into, where they were advertising speeds that no one would see on the charger they were using.
 

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Discussion Starter #18
Will be repeating the route this weekend, but going a bit further south to June Lakes. Hoping to spend less time charging now that I have a better sense for the amount of energy needed to cross Sonora Pass (perhaps can drive less conservatively too). If only the Bolt's range at 75 were the same as at 60...
 

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I keep thinking of things. Note that the charge rate for the Bolt steps down as the battery takes on more charge (actually, all EVs do). Because of this, most people rarely charge over 80% because it just takes too long. For best efficiency, drive until your battery is a low as you're comfortable with, then charge up enough to get you to the next charger.
 
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