Mountain climbing in a REx

[TomMoloughney]

Many in the US have complained because they cannot manually turn on the i3's range extender at a higher SOC if they know they will need the extra energy later in the journey for strenuous driving, like going up long, steep inclines. The European i3 allows the driver to control when the REX turns on and maintains the state of charge. Without a "Hold" or "Mountain" mode for the i3's range extender you might think driving up a 14,000 ft elevation wouldn't go so well.

Don Parsons gave it a try and wrote about the experience for my i3 blog: Mountain Climbing With an i3 REx

 

[drb]

Don, great story. Your experience will encourage the rest of us REx drivers to attempt more than city driving. I did a 211 miles round trip recently and on the way back, mostly on REx, had a big slow down as I climbed a long grade. Other than that, the car functioned as intended. I now have 1,000 miles on my i3 and my brake service light came on yesterday. Did you get to the bottom of why your brake was not functioning properly?

 

[DHP]

drb, no, the brake error was probably related to the 12v issues that many others are seeing. Most of the time my battery state of charge is above half so never saw this before or since. I'm a huge fan of "unleashing the REx" for mountain trips or longer drives by utilizing the same setup as the European i3 and being able to turn on the REx gas engine when you know you want to maintain the battery as long as possible. I'm close to 2000 miles and am still under 100 miles on the REx.

 

[jadnashuanh]

As long as you understand the limitations, the REx can be a good option. It's when you try to treat it like a 'normal' car that it can fall short in those stressful, high current draining situations that it can let you down.

 

[TomMoloughney]

As long as you understand the limitations, the REx can be a good option. It's when you try to treat it like a 'normal' car that it can fall short in those stressful, high current draining situations that it can let you down.

Exactly, it has limits and the owner needs to know how to use it properly so they don't find themselves in a potentially dangerous situation.

Don, was in a unique situation where the flow of traffic up the steep incline was slow enough so his limited-power i3 REx could keep up with everybody else. If this journey commanded speeds over 35mph the entire way he would have been driving much slower than the typical flow of traffic and perhaps had problems.

If you drive a REx it's good to test it out a bit and puch the limit to see how it acts when the REx can't provide enough power to maintain the speed you want it to, this way you aren't surprised and stressed if it does happen. Also, keep an eye on the SOC bar and if it shrinks to the point of it nearly disappearing then slow down a bit and allow the SOC buffer to build up a little. You can even pull over for a couple minutes if you are in a safe area to do so and let it charge back up to the 6% REx limit. Once you get used to how it works you can really get the most out of it and not worry about being surprised by the reduced power mode.