Long commute. Is this appropriate for the i3

[Phillaforest]

Hello,

I am contemplating purchasing an i3 but I am wondering if my usage is a good fit for it.

My commute to work is 100 km (62 miles), both ways, pretty much all on highway. I do it 2-3 times per week. I will have access to recharging station at work and at home. I also intend to buy the range extender. In theory, the range announce by BMW should be sufficient that I should be able to get to work without using the range extender.

My main concern is about the efficiency of the battery through time. I average around 32,000 km per year (20,000 miles). I live in Quebec where winter can be cold. A combination of weaker battery and cold condition could mean that I end up using the range extender regularly (on almost every leg of my commute during winter). I wonder of the combination of recharging twice a day with a frequent uses of the range extender in winter months could lead to a premature deterioration of the battery?

Here in Quebec, the combination of very cheap electricity (all from Hydro) with the high price of gas makes the economics of the i3 very attractive, even for long commute. Does someone has a similar experience on the usage of the i3?

Thank you very much.

Philippe

 

[WoodlandHills]

Based upon reports here by cold climate owners, it might be iffy in the winter to make the trip on battery alone. It depends on how much heat you need and how you get it (Cabin vs seat), your driving style is also going to be very important as well as being able to Precondition the car before leaving while plugged in at each end.
What sort of charger will you have access to at work? You are going to need to have 100% SOC and a preconditioned cabin and battery pack when you leave work at the end of the day to be sure of getting home on battery. Are there any long hills in the last few miles before you get home: the REx does not do well at low SOC under heavy load sometimes. If your route is mostly flat you should not have any problems with the REx and you might do the whole trip on battery.
If you were able to enable the REx Hold option like in Europe and the UK, you could start the REx an a higher SOC and thus have a larger battery reserve for any hills you might encounter. Since you seem to be going between the same two places you would be a perfect candidate to benefit from the new navigation/GPS based software update to the REx controls that BMW is introducing in a month or so.

 

[pdurham]

I'm by no means a battery expert, but I do read just about everything I can find on the subject. Information available online suggests that battery degradation is much more related to total mileage (i.e. battery cycles) than to time. So of course, you will suffer some battery degradation due to usage, but there's no reason to expect it will be worse than anyone else incurring the same number of charge/discharge cycles. I haven't seen anything to suggest that a couple battery charge/discharge cycles a day should be any different than the same number of cycles spread out over more time, as long as you're not using a fast charger (though there is even evidence that fast charging has less impact then previously thought). And I haven't seen anything to suggest that discharging the battery to the point of automatically triggering the REx makes any real difference (it just counts as one battery cycle, but do plug it in promptly when you arrive at either end). Also, available information seems to agree that while heat can result in accelerated degradation in some circumstances, cold has less if any impact on long-term degradation. Of course, it does reduce capacity while it is cold, and reports on this forum and the i3 Facebook page suggest that the cold weather reduction in range is significant. (Read Tom Moloughney's post about his 162-mile road trip at http://bmwi3.blogspot.com/. The combination of cold weather, highway speeds, a loaded car and use of heating caused the REx to come on after only 48 miles on Tom's trip.) I'm in Tucson, AZ, so I have very little experience on that issue. But based on what I've read, I believe you're right to choose the REx if only to allow for cold-weather range reduction. Let's assume the worst case: that on very cold days in the winter you drive 48 miles on the battery and the rest on the REx, then charge fully at work and repeat that on the return trip. (Use preconditioning to warm things up before you unplug at both ends of course.) While some i3 REx drivers seldom engage the REx, many appear to use it regularly. Your pattern doesn't seem out of line to me.

One thing you didn't specify is what highway speed you'll be driving at. The difference between 65 mph and 75mph, for example, can be significant. Traveling at 65 mph, we generally get around 70 miles on the battery (sometimes a little more, sometimes a little less). Again, that won't apply in really cold weather. Bottom line: if you have Level 2 charging available at both locations, it looks like you'll drive the entire round trip on the battery a great deal of the time. Sounds to me like an excellent situation for an i3. Sure, winter where you live isn't ideal for an electric car, but I haven't seen any information that the usage you described, other than simply your total mileage, will accelerate battery degradation.

One final thing to consider that you didn't mention: one of my criticisms of the i3 relates to highway driving in windy conditions. The car's taller profile and skinny tires do make it more sensitive to crosswinds, and headwinds of course have a big impact on battery range. If you'll frequently encounter wind, try to test drive the car under such conditions. Some people are bothered by this, some aren't.

BTW, WoodlandHills makes excellent points.

 

[jadnashuanh]

Having the proper air pressure in the tires can make a big difference on how it feels on a windy day! I think it is more the fact that the car is quite upright and light weight than the tires, but the tires do make a difference depending on the air pressure in them.

BMW's (USA anyways) battery warranty seems pretty straightforward and should go at least part way to allay your fears: 100K miles or 8-years, it must hold at least 70% of new capacity or it will be fixed under warranty. The vehicle logic never charges to a 'real' 100%, or lets you discharge them to an actual flat value. Given the state of the art on batteries, that warranty is pretty good.

 

[pdurham]

Yes, forgot to mention the light weight as a contributing factor to the car's tendency to get pushed around by the wind. And I agree that tire pressure is important. I tried over-inflating by a few pounds to increase efficiency but didn't like it's impact on wind-sensitivity as well as ride. Not that much impact on ride actually, but my personal opinion is that it's already plenty firm. Can't imagine life with 20" wheels!

 

[Phillaforest]

Based upon reports here by cold climate owners, it might be iffy in the winter to make the trip on battery alone. It depends on how much heat you need and how you get it (Cabin vs seat), your driving style is also going to be very important as well as being able to Precondition the car before leaving while plugged in at each end.
What sort of charger will you have access to at work? You are going to need to have 100% SOC and a preconditioned cabin and battery pack when you leave work at the end of the day to be sure of getting home on battery. Are there any long hills in the last few miles before you get home: the REx does not do well at low SOC under heavy load sometimes. If your route is mostly flat you should not have any problems with the REx and you might do the whole trip on battery.
If you were able to enable the REx Hold option like in Europe and the UK, you could start the REx an a higher SOC and thus have a larger battery reserve for any hills you might encounter. Since you seem to be going between the same two places you would be a perfect candidate to benefit from the new navigation/GPS based software update to the REx controls that BMW is introducing in a month or so.

Thank you very much for the info. Can you explain the function of the navigation/GPS with regards to extending the range of the battery?

 

[nowtta60]

I'm in a similar situation - 60 miles to work and 62 back, no charging at work as I'm a freelance contractor who moves jobs frequently. REX was essential. I actually ordered in my last contract which was a 150 mile trip at the start and end of the week with about 30 miles pottering around in between. In that case - the BMW garage I ordered from was over the road from work and has a free (for now) L2 charger.

Where I currently work so will be doing a mix of driving and train journeys... mainly because I can't stand to get up at 5.30am every day to avoid the traffic and have a 2 hours commute instead of 1h15. Thankfully there's a BMW dealer with a charge point about 1 mile from work, so can walk the last bit and get some free exercise and a nice walk thru a country park by the river as a shortcut. Option B is to "fill up" at a CCS 5 miles from where I work on the way in, and eat my breakfast / have a nap which I usually do in the works car park as its against my morals to start work before 7am! LOL.

I did a lot of reading up before sticking in my order, nearly cancelled when I realised it might not make the old jobs 150 mile trip on a full battery and full rex tank in winter, then realised there are now a bunch of CCS chargers in places I would be passing, and failing that... plenty of gas stations. Stick the hold mode on (or get it coded if it doesn't work like that in Canada) and run the REX tank down till the guess-o-meter says you'll make it on battery. Or - if you know you'll be passing a CCS on the way and it's not inconvenient to hang about for 20 minutes, run the battery down first and top it back up to 80%. Then run it back down to 75% and engage hold mode. On your 60 mile journeys - I'd not bother with hold mode.... maybe keep it at 10% if you have a big hill to climb on the last leg of the journey.

In summary - get the REX, you'll be able to make journeys you would never be able to make without it. I'd prefer to have it and never need it, than not have it and constantly be worrying about whether I'm going to reach the charge point I planned. Especially in 5 years from now when there's 60-80,000 miles on the clock. Just hoping BMW will take the same path as Telsa and offer battery upgrades for people with older cars, but using newer battery tech. The Telsa Roadster just got an upgrade offer to a 400 mile battery. If they can eventually hit that in the i3... I'd ask them to pull out the REX. Or maybe trade in for an i5 touring coupe convertible made possible by carbon fibre / alloy and a bigger frunk ;-)

 

[Tomasz]

I commute 82 miles both ways twice a week. I leave home with full battery and full tank, drive first 15 miles or so until the SOC drops to 75% and then hit the REx hold. I drive on REx to the point where battery range equals remaining distance and turn off the REx then (usually about 25 miles). Most of the time the Rex does not kick in at all, sometimes it kicks back in about half mile from work.
I do charge at work and repeat the process going back. Have absolutely zero problems and love the fact that I pay about 25% of what I used to pay for the same trip before I got i3 (and I was driving 30mpg car). And that I use zero gas for the remaining 5 days of the week - battery range is plenty enough for all my other driving needs.