New 2019 120 Pack Operation

[jadnashuanh]

In many places out of the USA, there are restrictions and/or extra costs for an ICE to enter or drive in some city centers. So, on your commute, you very well may want to preserve your battery capacity so it can be used once you get there and save some fairly hefty charges. The i3 is a world car...we may not understand or respect all of the capabilities that were put into the design. The neutering of this capability on the earlier MY i3s was done for credits that allowed BMW to sell more ICE vehicles in places like California without paying a penalty and thus raising the price on them. When used as intended originally, the REx is sort of redundant - it was a sales and marketing requirement for early adopters of the EV.

 

[JohnKelly]

Hello...

Why would you bother with starting the REX manually? Why not let it do its thing automatically?

Flexibility. If you are waiting for it to engage at 7%, you have lost that. You are at the whim of a hill or high speeds that you did not expect. If you run your battery down that far the Rex may not keep up the state of charge and you will run out of battery and have to slow down... not always safe. It will keep up on flat ground at about 60 mph with a small amount of heat or defrost on. Much better to choose when you want to run it, based on where charging stations are and how far you want to go without stopping to charge... you will be stopping for gas frequently if you decide to skip charging stations or there are none available and you are on a long trip. You may expect a station to be available that is occupied or non-functional. The Rex eliminates range anxiety if you have it set to manually engage anywhere under 75% of battery. You can drive it just like you would an ICE if you do not have time to charge. It takes only a minute or two to pump 2 gallons of gas every 50-60 miles. It is a brilliant system when used to its full potential, and you can't do that the way are they are hobbled for the US market.

 

[Arm]

Hello...

Why would you bother with starting the REX manually? Why not let it do its thing automatically?

Flexibility. If you are waiting for it to engage at 7%, you have lost that. You are at the whim of a hill or high speeds that you did not expect. If you run your battery down that far the Rex may not keep up the state of charge and you will run out of battery and have to slow down... not always safe. It will keep up on flat ground at about 60 mph with a small amount of heat or defrost on. Much better to choose when you want to run it, based on where charging stations are and how far you want to go without stopping to charge... you will be stopping for gas frequently if you decide to skip charging stations or there are none available and you are on a long trip. You may expect a station to be available that is occupied or non-functional. The Rex eliminates range anxiety if you have it set to manually engage anywhere under 75% of battery. You can drive it just like you would an ICE if you do not have time to charge. It takes only a minute or two to pump 2 gallons of gas every 50-60 miles. It is a brilliant system when used to its full potential, and you can't do that the way are they are hobbled for the US market.

I guess but I still don't see the point for the majority of people as you are pointing out scenarios that are very rare and far and few between. The purpose of the i3 is to be an EV first, hybrid second. Besides the maintenance cycle, I don't plan on using my REX to charge my battery. My daily range is 160-180 miles when fully charged. The times I drive more than that in a single day can be counted on two to three fingers a year....if that...since I usually rent a car to drive very long distances.

 

[JohnKelly]

Even with pre-conditioning, I use my Rex more often in the winter (heat) because my typical round trip to town for groceries is about 65 -75 miles. I have the small 60 ah battery. The Rex is absolutely essential for me since I only have the one car and wish to be able to drive 300 or even 500 miles in a day if I want to. How do I know this? My first i3 was a 60 ah Bev, and there were many times where I had to go slower uphills and with no heat just to make it home. One small detour for a flooded road etc. could have left us stranded. Charging infrastructure is better near me since then, but I would rather have a 60 ah Rex than a Bev with a larger battery... at least until the charging infrastructure is more filled out and reliable. I am able to go pure electric 90-95% of the time, which is my goal after all.

When we had the Bev, we were forced to go the long way to a destination that was typically only 150 miles away simply because there was no charging infrastructure on the most straight forward route. What would have been a 3 hour trip in an ICE or a 5 hour trip if there was a charging station at the halfway point of the trip became a 10+ hour trip! We were cold and uncomfortable, and had to stop at whatever EVSE was available becasue we could not be sure the next one would work. There are some of the reasons why there are far more Rex sold in the US than Bev.

About once a month we go on a slightly longer trip... maybe 200-250 miles round trip. We do not stop until we reach the nearest DC fast charger, and end up burning about 1 gallon of gas on the way there and another on the way back... with perhaps a few stops to sip on level 2 near shopping. I generally want a buffer of 25% battery in case something goes wrong with the Rex. That is when I usually start the Rex. The Rex is brilliant for this type of use. I do not require 2 cars. I drive electric the vast majority of the time and I can go anywhere I want without worrying about charging stations malfunctioning or already being in use. This is not for everybody, but for us it is perfect. I am going to Montana in February.. a 1600+ mile round trip, with DC fast charging on I-90 every 80 -100 miles or so. Should be a blast... with Rex, I have no worries. With a Bev, I would be subject to the vagaries of our unreliable EV charging infrastructure. If I rented a car for longer trips, I would be burning a lot more gas than I do, and I hate driving those stink pots anymore.

 

[Arm]

Even with pre-conditioning, I use my Rex more often in the winter (heat) because my typical round trip to town for groceries is about 65 -75 miles. I have the small 60 ah battery. The Rex is absolutely essential for me since I only have the one car and wish to be able to drive 300 or even 500 miles in a day if I want to. How do I know this? My first i3 was a 60 ah Bev, and there were many times where I had to go slower uphills and with no heat just to make it home. One small detour for a flooded road etc. could have left us stranded. Charging infrastructure is better near me since then, but I would rather have a 60 ah Rex than a Bev with a larger battery... at least until the charging infrastructure is more filled out and reliable. I am able to go pure electric 90-95% of the time, which is my goal after all.

When we had the Bev, we were forced to go the long way to a destination that was typically only 150 miles away simply because there was no charging infrastructure on the most straight forward route. What would have been a 3 hour trip in an ICE or a 5 hour trip if there was a charging station at the halfway point of the trip became a 10+ hour trip! We were cold and uncomfortable, and had to stop at whatever EVSE was available becasue we could not be sure the next one would work. There are some of the reasons why there are far more Rex sold in the US than Bev.

About once a month we go on a slightly longer trip... maybe 200-250 miles round trip. We do not stop until we reach the nearest DC fast charger, and end up burning about 1 gallon of gas on the way there and another on the way back... with perhaps a few stops to sip on level 2 near shopping. I generally want a buffer of 25% battery in case something goes wrong with the Rex. That is when I usually start the Rex. The Rex is brilliant for this type of use. I do not require 2 cars. I drive electric the vast majority of the time and I can go anywhere I want without worrying about charging stations malfunctioning or already being in use. This is not for everybody, but for us it is perfect. I am going to Montana in February.. a 1600+ mile round trip, with DC fast charging on I-90 every 80 -100 miles or so. Should be a blast... with Rex, I have no worries. With a Bev, I would be subject to the vagaries of our unreliable EV charging infrastructure. If I rented a car for longer trips, I would be burning a lot more gas than I do, and I hate driving those stink pots anymore.

I think then your issue lies with the very short battery only range you have. I have a 2019 i3s and I get around 170 miles of range per charge thus far. i could not imagine needing to have my REX run unless I decide to go to Vegas or something.

 

[JohnKelly]

That's nice for you, but I could not afford that much battery, and tens of thousands of these cars have the smaller battery. In addition, since I only wanted to have one car for frugal reasons and also be able to take longer trips a couple of times a month the bigger battery would still require that I stop and plug in and wait. If there are only level two charging stations on my route, I would be sitting charging for hours. With my Rex, I can either keep going, or stop and charge. Options. Like I said, the Rex is brilliant for some of us. I would certainly prefer to have a Bev and be able to DC fast charge virtually anywhere-anytime, but we are not there yet. Not even close. When I had a Bev, we spent many hours sitting wrapped up in blankets charging at level two because the nearest DC fast charger was over a 125 miles from us at that time and in a direction we rarely went. I once got down to .5% on my battery on I-5 before finding a 110volt plug at a rest stop.... I was that close to having to be towed. I do not understand how folks can fail to understand just how much flexibility you have with a Rex. If you do not want to spend the time charging, you do not have to. If you want to plug in and wait, it is an option , not a necessity. This is an advantage in many scenarios. By the way, I always unplug for Bevs if they are in need (insert smug emoticon). This will all be moot once our EVSE infrastructure is filled out a lot better than it is... might be able to afford a big-battery-Bev by then too : ) In the meantime, this Rex is an extraordinary car that we enjoy very much with NO range anxiety whatsoever.

 

[Fisher99]

I think that both of you have very valid points. A BEV works perfectly for one of you but not for the other. Perfectly understandable. Neither view is right or wrong. Just situation dependent.

My experience happens to most closely parallel John's. Even if my i3 had the 170 mile battery range, I would need the REX. For one thing, I have discovered in my first winter with my i3 that our cold weather (currently high 20's and low 30's) is reducing my battery range by about 25%. But even in the warmer weather I find myself using my i3 for longer trips that would simply not be acceptable even with 170 mile battery range. My REX allows me to do that. My driving style flip/flops depending upon whether I am driving short range or long range. Much of my driving is limited to 40-50 miles so I run entirely on battery with the REX as a backup. When I hit the road for longer trips I switch to the REX as soon as it allows me to (around 75% battery) and and keep the battery as a backup.

Different strokes for different folks. No right or wrong. But for me personally, I would need a minimum of a 300 mile range in order to go battery only. Right now only a Tesla delivers that range, but my i3 with REX allows me to get by quite nicely with a reduced battery range.