I’ve been driving my BMW i3 for 2.5 years, but next month for the first time I plan to take it on a long road trip. And not just any road trip … from the Bay Area to Reno, NV, which means climbing the Sierra Nevadas.
Let’s say I fully charge up in Sacramento, and my normal range is 160 miles on a charge. On level ground this would easily take me the 135 miles to Reno. But between Sacto and Reno is Donner Summit (7,300 ft). Just past the summit is Truckee CA (5200’) and its fast charging stations, 100 miles from Sacto. Can I expect to make it to Truckee? Fully loaded with 2 adults and suitcases and a dog.
(If we run out of juice we’d be forced to revert to cannibalism like the Donner Party. )
That brings up an interesting question. If you had a generator, fuel and the circuitry to get charging voltage from 110v or 220v, could you make an emergency charge that would get you to the next charger, say, 50 miles?
Since getting stuck puts you in such a difficult predicament I’d suggest renting a car or trading your car with a friend. If you do run out of juice somewhere in the mountains it will take quite a while for someone to get to you and tow you into Reno to recharge, not to mention the cost and inconvenience. And if that really does happen how are you going to make it back to Sacramento? I’m betting on the dog eating you before you eat the dog… the kids are on their own.
Minus the reduced range caused by the additional weight, drag, and/or rolling friction (depends on how you’re carrying your portable charging system along).
Level 1 charging is single-digit miles per our so your compact generator isn’t going to get you far fast. In theory, you could put a larger, more powerful generator on a trailer but all that extra weight & rolling resistance is going to sap your mileage
Sacramento is downhill from Reno. Reno’s at like 4500’, while Sacramento is just barely above sea level. There will be some climbing to get over Donner Pass of course, but less so than coming from the other direction.
Assuming that the map apps are accurate wrt charging stations, I could charge up in Sacramento, then again in Auburn, and again in Colfax, and at some random spot in the mountains west of Truckee.
So it looks like it’s doable, but possibly a PITA.
When I put a 60Ah i3 into a better route planner it shows you doing fine from San Francisco to Colfax, but from there it has you limited to 60 and 55 mph, with a charge in Soda Springs. Particularly from Colfax to Soda Springs, it has you going from 100% to 9% in 31 miles and not exceeding 55 mph while you do it.
So it looks like it might be possible, but not fun.
Reversing the trip, you can get from Truckee to Colfax without charging, and no stretches of limited speed.
A better route planner is the website. I happened to be using the iPad app, though. I use it to plan Tesla trips. It has a real time driving mode you can use with a subscription, but I’ve never bothered as the Tesla in car stuff is good at predicting charging stops. The in car nav is not good at “what if” type alternative planning, though.
If you can figure out where to click, you can set ABRP to take into account passengers, weight, battery degradation, and maybe more.
I was thinking of that old joke where Grandpa tells you how he had to walk to school and home “uphill, both ways.” You climb one hill but then you must be going downhill, getting momentum. I’m not sure how your BMW works however, and I got a C in Physics anyway.
I did want to point out that these batteries are made near Reno, in Sparks.
I saw a program on Prime where two young folks wanted to RV up to the Arctic Circle. Rather than install an Onan or other separate diesel generator, they had their diesel pickup built with two generators under the hood—one to power the truck and one to recharge the deep cycle “coach” batteries shown here. At 100Ah each, they aren’t cheap…but it looks like they’re about the same as your BMW’s rating. No way to schlep one along and charge the BMW from it if you run out?
Thanks for the recommendation! I can’t believe this is the first I’m hearing of this indispensable app.
I immediately ran into a snag with the app, describing which model/battery I have. My owner’s manual is silent on the subject (thanks, BMW…) I happened to have saved the window sticker, which describes it as 42 kWh. The app gives me choices expressed in Ah – 60, 90, 120. So what do I have and how do I answer the app prompt? TIA.
If you indeed have the 42kWh battery, that is the 120Ah model.
Now the 2019 model, which will comes with 120 Ah batteries in a 42.2-kWh-battery pack, will be able to travel about 153 miles on a single charge, BMW said.
@echoreply, since you looked already; how many charges are there at the stop in Soda Springs? Is it likely he’s going to get there & have to wait for a charger? Also, does that app calculate passenger compartment weight as 4 big guys weigh a couple hundred pounds more than a petite couple with young children even though both are 4 bodies?
The i3 is ~1450 kg, and Donner summit is at 2200 m. That means 31.3 MJ, or 8.7 kWh, just to lift the car. Passengers and luggage likely bump that to 10 kWh. And there will be some inefficiencies on top of that, due to some downhill parts that don’t quite make up for the extra uphill (though the regeneration helps a lot).
Aside from that, though, there really is a direct translation between mass-height and energy. Electric motors are so efficient that you can get pretty close to the truth just by looking at the theoretical limit. I’ve done some tests with my Tesla and came within 10%.
That requires switching to another app, Plugshare, because ABRP doesn’t show it. Looks like there are two 50kW chargers at a gas station, and two 100kW chargers at a rest area (plus a 6.6kW somewhere). I have no experience to say if there is likely to be a wait.
ABRP let’s you specify the extra weight in the car. I recommend weighing your passengers like in general aviation. I have an extra 500 pounds set. It does make a difference in ABRP’s estimates, but mostly on charge time and speed limitations.
ABRP is not perfect. For example it refuses to let me charge in both Cisco and Sweetwater, unless I also charge in Llano. That is just silly, as Sweetwater is past Cisco, and Llano is before Cisco (Tx).
With the correct battery type factored in, ABRP says I can make the trip with 2 stops - Sacramento and Colfax. And given the multiple charging opportunities between Colfax and Reno, it might be doable.
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