300m ChaDeMo trip: slow with fewer or fast with more chargs

[dava71]

Hi all

I will be picking up a Citroen C-Zero 300 miles away from home next weekend. I have to drive Birmingham -> Dundee and plan to make use of the Ecotricity/CYC ChaDeMo chargers (when I discovered this car + Miev/Ion had ChaDeMo charge
capability and cost < 6000 gbp for cars < 3 years old, it seemed pretty much a no-brainer vs Zoe/Leaf?). I have my cards and have tested them on a recent EV trip with a Zoe.

My question is this - if chargers are spaced approx 30 miles apart, which strategy will result in the shortest travel time

A) driving fast (65-70 mph), stopping at every charger and charging to 80%

B) driving slow (55 mph), stopping every 50-60 miles and charging to full

Finally, to what extent does A vs B depend on the distance between the chargers

I believe I have seen a post somewhere where somebody properly calculated this but I cant seem to find that anymore

thanks for your help
Daan

 

[pbui19]

I would err on the safe side and go 55mph, in case a charger is non-operational. Unless you can confirm the stations being operational before leaving. It's only 1 hour difference. And bring an extension cord. What about the weather ?

 

[JoeS]

My question is this - if chargers are spaced approx 30 miles apart, which strategy will result in the shortest travel time
A) driving fast (65-70 mph), stopping at every charger and charging to 80%
B) driving slow (55 mph), stopping every 50-60 miles and charging to full...

dava71, thanks for your post and congratulations on getting a C-Zero!

Great question! Shortest travel time vs. 'safest' strategy, hmmm…

The dilemma we face is that the best utilization of CHAdeMO occurs when the battery is almost empty: full CHAdeMO power can be applied for a good part of the recharging cycle and a lot of miles can be infused in a relatively short amount of time. If the battery is half-empty, then full power is only applied for a few minutes before it starts tapering off. In my case, it always stops at 80%SOC. The problem with this strategy is, as pbui19 pointed out, if a charging station is down then you're stuck and have to rely on 230vac which would negate any time savings you might have accrued along the way.

Since this is going to be your first excursion, I would suggest erring on the 'safe' side and plan on stopping every 30 miles to recharge, but also driving conservatively so you could make it to the next CHAdeMO charging station down the road in case one is down.

You have opened up an interesting proposition which, given an adventuresome person and assuming no station failures, would make for an interesting calculation. Going 60 miles starting with a 80% charge would not work for me...

Edit: I just re-read what you wrote and see that I did not properly answer your question. Charging to full, i.e., CHAdeMO to 80% followed by L2 to top-up, would not be time-effective as you will spend an hour+ topping up. Better to rack up another 30 miles and plug into CHAdeMO for 15 minutes to get to 80% and keep going. Our little cars do not lend themselves to long-distance driving if you're in a hurry.

 

[Zelenec]

Hi all

My question is this - if chargers are spaced approx 30 miles apart, which strategy will result in the shortest travel time
A) driving fast (65-70 mph), stopping at every charger and charging to 80%
B) driving slow (55 mph), stopping every 50-60 miles and charging to full
Daan

I believe the most reasonable way would be driving slower and charging to 80% or less when needed. Charging over 80% takes a lot of time.

 

[Aerowhatt]

Congrats on your purchase. I can't imagine that you will be disappointed.

I vote with others to take the more conservative approach. My experience with fast charging (although limited) is that it has only been available less than 70% of the times I have attempted to charge up. Mostly equipment problems and also network problems. One time I spent 25 patient minutes on the phone with customer service while they tried and tried to communicate with the unit and bring it online. Only to leave without getting a charge. In this instance the unit was indicated as not in use and functioning properly, on the internet App, before I arrived.

Perhaps your network is doing a better job, be ready with plan B.

Aerowhatt

 

[jray3]

Dava, I too vote option A, but with a twist. If you see another EV, drive it like you stole it and beat him to the next DCFC station!! Here in he northwest U.S., lineups at stations are common, and I've learned that at 30-45 mile spacing, the LEAFers tend to stop at EVery station too, but they have a habit of camping out past their 30 minutes to 80% (because their cars will allow it). So I try to leapfrog them to the next station, then it's smooth sailing. Find out which app is most used in your area for updates on station status and USE IT. I had an hour delay just yesterday because I didn't check whether a Nissan dealer's station was online before driving there, and had to use L2 to make the next DCFC. Some dealers are very unreliable, whether it be blocking with parked cars, or station maintenance.

 

[JoeS]

Just for fun, I looked up PlugShare for the Birmingham-->Dundee trip, and was surprised by -

1. The proliferation of CHAdeMO stations (compared to when I was there three years ago)
2. The number of non-operational stations. :evil:

dava71, I hope you can give us feedback about your trip. Hopefully, you also pick a good weather window!

 

[wmcbrine]

2. The number of non-operational stations. :evil:

Yeah, why do these things seem to go down so much? :?:

 

[Aerowhatt]

Yeah, why do these things seem to go down so much? :?:

From my experience it's not the unit that won't work It's the remote network part of them that is the biggest glitch. If they just put a cash counter receiver on the side of the stupid things (Like a vending machine) that turns it on for x time depending on how much money you put into it. Well, then I bet I would have gotten a charge every single time except the one time when the chademo plug was damaged. These units have to phone the mother ship(s) to do anything at all. Nothing set up like that works reliably, not even military grade stuff!

Aerowhatt

 

[jsantala]

I don't consider driving 50-60 miles between fast charges possible. You might get that far on a full charge, but not between fast charges, which generally only go to 80% and can get you to only near 90% in any reasonable time. So if you get the car fully charged, you could get to a station 50 miles away, but after that you'll need to make stops more often. That's also providing you know how to maximize the energy consumption of the vehicle, weather is good (not raining) and don't need to use heat etc.

 

[JoeS]

jsantala, agree with your assessment. The 50-mile limit at 80%SOC would be iffy and rely on hypermiling skills, ability to drive slower (often not possible on motorways), no altitude increase, and no headwinds.

Been thinking about the weather: if dava71 starts off just at the very start of an incoming low pressure system then he'll have a tailwind and hopefully get up to Dundee before the rains/snows hit.