Advice before purchase

Hello, I have a round trip of 160miles for about a week, then im moving closer and will have a 70mile round trip. If I purchase the BMW i3 with the range extender would I be ok to charge after about 80miles? and how long do you think I would need to charge for?

WIth the range extender, if you don't mind using gasoline, you wouldn't need to recharge until you got home again. You'd also have to refill the tank. It depends on what type of recharging unit you might have...120vac (level 1 in the USA), level 2 (240vac), or a high voltage DC CCS unit (not something the average person would buy). A typical 120vac receptacle is only 15A, and the biggest EVSE you can safely use on it is 12A...with that, you would NOT be able to recharge the battery during a typical workday. Not all level 2 units are created equal...many commercial units are powered by 208 vac, so even if it's a max of say 32A (about the max the i3 can use), for 80-miles, it would probably take about 4-hours. If you have a 240vac unit with about 32A, 80-miles would probably take about 3+ hours. Now, if you have access to a CCS unit, they also are not all created equal...the max generally available is a 50Kw unit, some are as small as 24Kw. At 50Kw, you'd get nearly 80% from empty (you wouldn't be) in about 30-40 minutes.

I assume you're considering a 2017 model with the larger battery.
A few notes from my experience with my 2017....
I get 105-110 miles on a fully charged battery before the REx kicks in. I've only used it in the summer and I expect mileage will be less in the winter.

If you're in the U.S. note that if you plan to use the REx on a regular basis you should code the car so that you can manually turn it on somewhere <70% charge. Otherwise it will come on around 6% and the REx won't keep up with the current draw unless you drive gently. If it gets to <~5%, the car will stop and cannot be restarted until it is charged. IMO the margin for error is way too low. European models already come coded so that you can turn it on <70% (maybe it's 75% but you get the idea).

When using a level 1 charger (the one that comes with the car, 110V) my range increases 5 miles per hour.
With a level 2 charger, the range increases 13 miles per hour. As Jim says, YMMV
With the DC fast charger that I use, my battery will be 80% charged in 30 minutes but it takes another 30 minutes to get to 100%.

theothertom said:

When using a level 1 charger (the one that comes with the car, 110V) my range increases 5 miles per hour.
With a level 2 charger, the range increases 13 miles per hour. As Jim says, YMMV
With the DC fast charger that I use, my battery will be 80% charged in 30 minutes but it takes another 30 minutes to get to 100%.

Click to expand...

I thought I read somewhere that the new model will charge at the full rate until it gets to about 90-95% and then it gradually decreases the charge, unlike the older models that would do this around 75%. Have you noticed this?

I had a 2014 and now have a 2017. Both seem to start tapering off between 80 and 90%. Maybe there's a difference that's detectible with specialized equipment/software but in normal use, they feel the same.

brorob said:

theothertom said:

When using a level 1 charger (the one that comes with the car, 110V) my range increases 5 miles per hour.
With a level 2 charger, the range increases 13 miles per hour. As Jim says, YMMV
With the DC fast charger that I use, my battery will be 80% charged in 30 minutes but it takes another 30 minutes to get to 100%.

Click to expand...

I thought I read somewhere that the new model will charge at the full rate until it gets to about 90-95% and then it gradually decreases the charge, unlike the older models that would do this around 75%. Have you noticed this?

Click to expand...

I haven't checked when using the supplied L1 charger, but it tends to slow down around 80% when using the DC fast charger (L3 charger).

Some of the rate of charge is dictated by how hot the batteries get...expect differences winter/summer, with a taper off sooner during the summer.