Drove my 2017 BEV ~400 miles on Saturday

[Obioban]

This weekend I went up to CT to help a friend put his M3 back together. This was a total of ~400 miles, between the drive there/back and going out to lunch/dinner while there. I don’t generally plan to use the i3 for long trips, but since I was babyless and had never used the fast charger port on the car, I did it just for giggles. It was interesting, I don’t regret having done it once, but I don’t plan to do it again.

The drive is ~175 miles each way. Since fast chargers only work up to 80% battery (I had read), I planned it out so both ways I was going ~100 miles, fast charging, and then driving the remaining 70 miles. While I was at his house we plugged my portable 240V 16A charger into his clothes dryer plug, so I left his house with a full battery again.

Things I noticed…
1) Most striking to me: both fast chargers I used maxed out at 50kw. This was not a problem for me, as the i3 also maxes out at 50kw. But, it does mean that something like an etron would only charge at 1/3 of its potential fast charge speed! I don’t know how representative that is, generally, but they were both pretty new chargers (one installed by Electrify America—which I believe is VW owned?)
2) The chargers aren’t the most reliable. The first one I had to call the number on the phone so they could remotely restart it, so it would function, and then it wouldn’t unplug from my car till I called them again and the released the lock. The second one ended the charging session early twice—at 33% and 70% full battery. If I hadn’t been standing there to manually restart, that would have been very annoying (come back to an uncharged car).
3) Despite claiming 50kw of charging, they only actually charged at 44-46kw
4) The i3’s air conditioning is not powerful enough to effectively cool the cabin while parked in the sun, while DC fast charging (as the AC system is cooling the battery)
5) Fast charging actually continued at full speed (~45kw) up to ~85% battery, and was still charging at 35kw at 93% battery when I lost interest and unplugged—better than I expected given the claim of only fast charging to 80%.
6) 25 min of fast charging feels like forever when you’re 70 miles from home at 1 am.
7) On the 100 mile leg, I had to seriously limit my speed. Instead of being annoyed by the 94mph speed limiter like I usually am, I had to travel at ~85mph to have enough power to make it to my planned charger.
8) if the fast chargers had been a bit less reliable than they were (not functioned at all), I would really have been SOL-- I was judging my speed/range to arrive at each of them with ~5% of battery remaining.

It was an interesting experience. I won’t be repeating it any time soon—will use a gas car for long trips.

Between the trip itself and taking the car to lunch/dinner during the day, the car was continually either driving or charging continually for 25 hours (left at 5am, got home ~2am, and then it charged ~4 hours on my 240v 30A charger from near empty).

 

[JohnKelly]

Thanks for your story! Takes a certain amount of faith in the infrastructure to do what you did. We just circumnavigated the beautiful Olympic peninsula in Washington state in our 2015 REX doing a bunch of extra driving around hunting for yard sales, garages sales, and the like. We did it in one day with multiple stops... took about 12 hours and we drove about 380 miles or so. We stopped for gas three times, and used the only DC fast charger on the peninsula to go from 30% to 80% before switching over to a free level 2 to top off while we had a meal. The whole trip was easy and a delight, with no hint of range anxiety. We did a similar trip in two days with our previous i3, a BEV. This was before there was a fast charger in Port Angeles, and several other levels 2s have since been added along the way since then as well. That was not as enjoyable a trip and it took twice as long, because we had to stop and charge whenever possible, not knowing if the next charger would be in use or out of order. I would much rather have a BEV, but until the infrastructure is more ubiquitous, it's a REX that works best for us. It is our only car, which means it is the practical choice for us. I am impressed by how seamless the experience is. We drive without using any gas most of the time, but when you need it, the REX is wonderful tech that allows us to only have one car and do everything we need to do, including longer trips. I am considering a 1600 mile round trip to Montana in the fall... we will see. Full disclosure, we were not driving at anywhere near the speeds you were... mostly 50-60 miles an hour, with a lot of slow neighborhood driving. I'm thinking Montana speeds will be slightly higher : )

 

[Obioban]

I can absolutely see how the REx would alleviate range anxiety. If it was my only car, or if i was using it for road trips more than once, I'd absolutely have that.

But, the BEV is really what brought me to the i3-- the weight of the car (REx is a >10% weight penalty) and the lack of almost any service requirements (brake fluid every 2 years) are the two main appeals of the car to me.

 

[JohnKelly]

Yep, I would go with the lighter weight and quicker acceleration in a heartbeat if it fit our situation. The difference in acceleration is noticeable.

 

[alohart]

3) Despite claiming 50kw of charging, they only actually charged at 44-46kw

That's a function of the i3's battery voltage while charging. A 50 kW charger outputs a maximum of 125 A, so a charging voltage of 400 V would be required to reach 50 kW. During charging, the i3 battery pack's voltage doesn't reach 400 V before the i3 battery management system starts reducing the charging current to protect the battery pack as it nears a full charge.

5) Fast charging actually continued at full speed (~45kw) up to ~85% battery, and was still charging at 35kw at 93% battery when I lost interest and unplugged—better than I expected given the claim of only fast charging to 80%.

The 80% limit applies only to the original 60 Ah battery pack. Your 94 Ah battery pack's battery manager maintains full charging speed into the 90% range as you reported.

7) On the 100 mile leg, I had to seriously limit my speed. Instead of being annoyed by the 94mph speed limiter like I usually am, I had to travel at ~85mph to have enough power to make it to my planned charger.

Speed kills This also applies to battery pack charge. The i3 is designed for low-speed urban/suburban traffic with a large interior volume for its size rather than an aerodynamic shape. Tesla Bjørn determined that to minimize travel and charging time in a Tesla Model 3, limiting speed to something around 75 mph was optimum. With the i3's worse aerodynamics, the minimal travel and charging time would likely occur at a lower speed.

8) if the fast chargers had been a bit less reliable than they were (not functioned at all), I would really have been SOL-- I was judging my speed/range to arrive at each of them with ~5% of battery remaining.

A lower speed would have resulted in greater range and margin without increasing total travel and charging time.

 

[Obioban]

For sure a lower speed would have improved my range! But, 85 is already pushing the lower limits of my ability to pay attention to driving :roll: