Tips for Long Distance Travel

[TonyWilliams]

Here is an article that I wrote concerning how to maximize your long distance travel time using fast DC charging:

http://insideevs.com/planning-a-long-journey-with-your-chevrolet-bolt-ev-or-opel-ampera-e/

A general rule of thumb is that you will need 30-60 minutes of DC fast charging to go 75-125 miles (120km to 200km) in your new Chevrolet Bolt EV or Opel Ampera-E.

This number may be significantly different than what your Distant To Empty (DTE) gauge, or “Guess-O-Meter” (GOM), might display since GOM estimates are based on prior driving consumption and can vary wildly in some cars, including the Bolt.

Not all cars will have the required DC fast charging port, as it is an extra cost option.

This might be counter intuitive to folks not used to an EV, but the fastest drive between two points is not filling up the battery at each enroute stop. Quite the opposite, since charging above 65% in a Bolt EV will significantly increase your charging time due to the reduced speed with which the battery can accept a fast charge above 65%.

Also, if you are using the fastest 125 amp “50kW” chargers, don’t drive slowly between charging spots to save energy. Drive normal freeway speeds of 65-75mph (105km/h to 120 km/h) to get the fastest overall speed in your journey. Above 75mph is not recommended, due to the relatively poor aerodynamics of the Bolt EV.

The Bolt EV will charge at an average speed of about 42kW at 125 amps while charging from 15% to 65%, which adds about 21kWh into the battery in about 30 minutes, and 30kWh in 45 minutes.

Obviously, the actual range is dependent on how fast you consume it, but we are assuming normal freeway speeds in nice weather on mostly level roads using an average consumption of 3.6 miles per kWh (277 Wh per mile) / 5.75km per kWh (174 Wh per km).

Again, to have the lowest overall travel time, it is not advantageous to drive slower to get improved energy consumption, since the fast chargers can upload power so much faster than you can consume it.

Cold weather, cabin heater use, wind, sustained high speed, hills, mountains, rain, snow, low tire pressure, etc, all adversely affect range and increase energy consumption.

EVgo network chargers are all on 30 minute timers EDIT: as of Feb 18, 2017, it appears that if you are on the $14.95 per month / $0.10 per minute plan with EVgo, the 30 minute time-out is disabled. To add 125 miles will take about an hour (again, if starting at 0% to 20%), and you need to interrupt your lunch or coffee break to swipe your EVgo card every 30 minutes. Fortunately, most other networks are on 2 hour timers. Charging above 65% will severely reduce the charge rate, and is not recommended, unless absolutely needed to reach the next charger, destination, or to compensate for adverse weather conditions.

Sure, when you leave your home or hotel, charge up all the way to 100% if you want to. But, you really want enroute chargers to be about 75-125 miles apart for the lowest overall travel time.

The car will charge the fastest from 0% to about 65%. The strategy is to burn down the battery at your first charge location to 10-20% remaining (or lower, if you are adventurous) and then charge for 30-60 minutes to add 75-125 miles of range each time.

In addition, you really only want to use the fastest chargers, and those that are the best are the ones that are 125 amps.

ABB, Signet, Efacec, Tritium and others build fast DC chargers that are 125 amp capable, and may be labeled by their network in the USA as either EVgo, ChargePoint, Greenlots, OpConnect, etc. Of course, you’ll want to have established accounts with each of the networks you plan to use.

The BTC chargers used at some locations by the EVgo network are only 100 amp capable, making your charge time increase about 25%.

The stand-alone CCS ChargePoint units (they won’t have a CHAdeMO plug on them) are only half power (60 amps), so I would avoid them like the plague. They will DOUBLE your charge time, and are really only useful if there is no other option.

With a little experience, you’ll be arriving at chargers with a low battery %, which is why it is wise to pick locations with more than one charger. Just one charger at a location could be broken, vandalized, busy, blocked, etc, and a low battery % limits your options.

Use PlugShare to verify that folks are not having recent problems with the charger(s) at your planned stops. Be sure to filter for “CCS” only.

If the Bolt EV were sold in Japan, it would have to have CHAdeMO, just like both the BMW i3 and Tesla (with a Tesla supplied adaptor). The Bolt EV cannot currently use CHAdeMO or Tesla Supercharger DC fast chargers, nor can it use GB/T in China.

Obviously, this planning only works mostly in the west and east coasts of the USA where there is adequate charging infrastructure, but it works almost everywhere in Europe and U.K.

So, in summary, plan your trips with chargers that are 75-125 miles apart, only charge enough to get to the next charger that is 75-125 miles away plus about 10-20%, and so on. This will take 30-60 minutes on the fastest 125 amp “50kW” chargers. Bump up your reserve to 30% or more in adverse weather, or climbing hills.

Try not to charge over 65% unless absolutely required. Use the fastest chargers rated at 125 amps, and plan to find locations that have more than one charger, or another nearby charger in case they are blocked or broken. Get whatever accounts, cards, apps, or fobs that are required by the various networks.

EDIT: I added a graph in the article to show a 650 mile / 1046km trip being done in 13-14 hours at 65-75mph on the original story linked above.

It’s important to follow the ABC rule… Always Be Charging. If you’re not driving 65-75mph down the freeway, you need to be plugged into a 125 amp charger.

In addition, don’t make the newbie mistake of plugging in and walking away. You MUST VERIFY that the charge actually starts and ramps up to full power before wandering off for tea and crumpets. Don’t forget to enjoy the trip!

 

[dndrich]

This is an outstanding post, and I have bookmarked it. The Bolt allows one to think about longer range trips than I considered in my Leaf. The strategy is the key, and your method makes complete sense. Well done.

 

[gpsman]

Yes, excellent post. Thank you.

I would like to add that "high power" charging drops at exactly 66% to "medium power" charging. And medium power is 24 kw. Thus there is no advantage to hunting down a 50 kw charger if your battery is starting in the 60's for percent charged.

Medium charging of 24 kw rate will continue up until the battery is 86% percent charged. Above 86% the charge rate drops to 16 kw rate.

Medium charge rate of 16 kw will continue until the battery is 93% charged. At this point charge rate drops to low, and low rate is 10kw.

I only went up to 95% and my car was charging at 10kw at 95%.

Interestingly, max rate I ever saw on a 50 kw charger was 42 kw. The same as many others have reported.

Summery:

??? to 66% = bounces between 37 kw and 42 kw
66% to 86% = 24 kw
86% to 93% = 16 kw
93% to ??? = 10 kw

 

[TonyWilliams]

??? to 66% = bounces between 37 kw and 42 kw
66% to 86% = 24 kw
86% to 93% = 16 kw
93% to ??? = 10 kw

That is some funky programming that GM has put it the Bolt.

The battery voltage is below 300 volts at 0% and 400 volts when fully charged, therefore at 125 amps, you'll get:

37.5kW = 125a * 300v (observed) - 0 - 20%
42.0kW = 125a * 340v (observed) - 30-50%
45.5kW = 125a * 365v (possible) - 50-65%

The amps start to reduce around 50%

 

[Anonymous]

Yes, Tony, nice post and article!

What electric car do YOU drive?

 

[TonyWilliams]

Yes, Tony, nice post and article!

What electric car do YOU drive?

Thank you. My current fleet is:

2015 Tesla Model S-70D (it's been driven coast to coast... 55,000 miles)
2014 Mercedes B-Class ED (Tesla drivetrain)
2012 Toyota RAV4 EV (Tesla drivetrain, 81,000 miles, it been from Mexico to Canada and return). I've owned a total of three of these.

There's a Tesla Roadster in the garage, and another Roadster in my shop, but neither are mine.

I previously owned two Nissan LEAFs, one of which I drove from Mexico to Canada in 2012. I was the first person to cross both Oregon and Washington using only DC charging via the brand new West Coast Electric Highway.

 

[Anonymous]

Nicely done! Let me buy you a cup of coffee next time you are in So Cal!

 

[Anonymous]

Tony: consider your statement:

EVgo network chargers are all on 30 minute timers. To add 125 miles will take about an hour (again, if starting at 0% to 20%), and you need to interrupt your lunch or coffee break to swipe your EVgo card every 30 minutes.

As we have discussed in a different thread, it appears that the EVGo monthly plan removes this 30 minute timer. I will be updating my EVGo plan soon to confirm this, but you already know this from your own experience.

The question to a driver is then is the 12 month subscription (at $14.95 per month) worth the ability to go enjoy your lunch or coffee break uninterrupted. My answer is YES!

And in further support of this answer, I note that if you only use EVGo for one hour every month, the monthly plan is still cheaper than their "free" plan (I have done the math in a separate thread entitled "NRG EVGo: someone check me on the math here!."

Plus there is always the $29 early termination fee if one must get out of the 12 month commitment early.

Based on these facts, I am going to convert my EVGo plan to the monthly fee and just be sure I use it for at least one hour every month (there is one 4.1 miles from my home next to a favored supermarket instead of the free DCFC located at the Chevy dealer [Keyes at Van Nuys!] that leased me my Bolt EV 4.0 miles from my home; although I will miss the freshly baked cookies at the dealer once a month!).

My EVGo needs are not that great (currently the Newhall Ranch DCFC when returning from Paso Robles with only an 80% charge as you advise), but I like having the option to use it with NO 30 minute timer when I need it the most.

 

[Nagorak]

I've been looking at some routes on Plugshare, and it seems like one of the challenges with long distance travel right now is the chargers are spaced pretty far apart. That means a lot of times you have to stop sooner than you'd like, because it's too risky to push it. A lot of places the chargers are 30 miles apart, which could cause you to stop early even if you theoretically have as much as 40-45 miles remaining (depending how safe you want to play it). If the chargers were spaced every 5-10 miles you could safely drive until the battery was almost depleted, and then you could charge from the lowest SOC possible.

It's actually even worse with shorter range EVs because with a ~100 mile range you may be forced to stop with a significant amount of charge remaining because you're not sure you can make the next leg (or you really cannot).

 

[TonyWilliams]

I've been looking at some routes on Plugshare, and it seems like one of the challenges with long distance travel right now is the chargers are spaced pretty far apart.

Companies like Lucid will likely use CCS public charging with a long range car (up to 130kWh), and this car as well as the VW diesel scandal money ($2 billion over ten years to install charging equipment) are two factors in portentially filling in those huge holes that Tesla solved with the Supercharger network.

I stress "potential", since nothing is guaranteed, and there may be competing interests. I seriously doubt VW has either the motivation (it's a penalty they are paying off) or the vision of Tesla, and they are years behind.

The fact that companies like GM specifically won't partake in charging infrastructure is just one of many roadblocks.

If you want to do serious travel in an electric vehicle priced at the level of a Bolt EV, I recommend waiting for the Tesla Model 3.

 

[Nagorak]

Yeah, the supercharger network really gives Tesla a big advantage in terms of usability. With it you can even drive cross country. Even with the range of a Bolt, you can't do that unless you're willing to settle for charging from NEMA 14-50s or 120v outlets. Along the west coast everything is fine, and even the east coast looks do-able, but in the middle you have very sparsely populated states who also aren't necessarily EV friendly.

 

[Anonymous]

Hi all. Newbie to this forum and to EV. I'm experiencing something interesting while charging my 2week old 17 Bolt. I'm charging at a Chevy dealer while travelling in Western NC and saw that the charger was charging at 28.4kw at around 70% full. Just over 80% full it jumped to 39.1kw, at 90% full it was charging at 42.1kw,and now at 92% full it's charging at 43.5kw and climbed up to 44.7kw when I stopped it at 94% . This is counter to what I've read here and on other forums. Any insight from the EV veterans here?

Thanks!

 

[SparkE]

Well, my first guess is that somehow you misread the information, as that is exactly the opposite of what is to be expected.

Firstly, most Chevy dealers with a DCFC have a 24 kW (60 amp) unit installed - they look something like this :

The color may be different, and they may not say "chargepoint". But they don't charge at over 24 kW - so if your DCFC looked similar to the above, it's a clue that somehow there was a misunderstanding on your part.


Secondly, the charge rate should be dropping *down*, not going up. At about 50-55%, it drops from (a max of) 45-55 kW down to about 37 kW. It will stay around 37kW until about 72-75% SoC, when it should drop to about 22 kW until about 90%.

Thirdly, if this happens to you again, (1) call over somebody from the Chevy dealer and explain your concern, and/or (2) take pictures to ducument the behavior.

 

[RickCH]

Those numbers look like they could be how many kwh have been supplied to the car. The Chargepoint chargers list that stat in the data that it scrolls through when it's in operation.

 

[SeanNelson]

Those numbers look like they could be how many kwh have been supplied to the car. The Chargepoint chargers list that stat in the data that it scrolls through when it's in operation.

I think you've nailed it!

 

[Anonymous]

Ahh, now that's starting to make sense. I may stop there on my way back and will check it out from this new perspective. Thank you!