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).
