Bigger battery + modular battery range extender lieu of rex

[cove3]

With a 1988 538e and a 1992 525i (used to have a 2002, 2800CS and 3.0CS), I was tempted by the i3 bev, but have decided to wait for a 2d generation i3. I just don't like the idea of lugging around a 250lb on board generator which to my mind defeats the whole idea of an electric car.

I'm wondering why, given the light weight design at 2654 lbs and room to spare, BMW didn't go for a 100 mile battery. It's an important psychological as well as a practical threshold. Rumors of a bigger battery to come help to hold me back

Also, in lieu of of a gas range extender, why couldn't the i3 have been designed with up to 10 optional 40 lb modular briefcase-like drop in batteries. At 400 lbs, this should give another 70 or so miles.

The advantage of this is that you can leave these permanently in to get 150+ miles OR like I would do, take them out like suitcases and only put as many in as you need for the occasional out of town trip. That way, I'm not lugging the additional battery weight around for the 95% of the time I don't need the range

These would have to be designed to snap in like a laptop battery. Maybe there's some showstopper I'm not seeing, but if offered this in the i3, I'd jump at it.

Ron

 

[bxb40]

Cooling those could be the showstopper... The main battery has active cooling using freon.

 

[fdl1409]

My range on country and urban roads is above 100 miles.

Frank

 

[Blue20]

My range on country and urban roads is above 100 miles.

Frank

Hi Frank, I see you are from Germany and have an REX. Do you mean 100 miles, or 100 km? The official rating for REX is only 72-mile on EV .

Phil

 

[mindmachine]

With a 1988 538e and a 1992 525i (used to have a 2002, 2800CS and 3.0CS), I was tempted by the i3 bev, but have decided to wait for a 2d generation i3. I just don't like the idea of lugging around a 250lb on board generator which to my mind defeats the whole idea of an electric car.

I'm wondering why, given the light weight design at 2700 lbs and room to spare, BMW didn't go for a 100 mile battery. It's an important psychological as well as a practical threshold. Rumors of a bigger battery to come help to hold me back

Also, in lieu of or as an option to a gas range extender, why couldn't the i3 have been designed with 8 optional 30 lb briefcase-like drop in batteries. At 240 lbs similar to the gas extender, this should give another 80 or so miles.

The advantage of this is that you can leave these permanently in to get 160 or more miles OR like I would do, take them out like suitcases and only put them in for the occasional out of town trip. That way, I'm not lugging 240 lbs around for the 95% of the time I don't need the range

These would have to be designed to snap in like a laptop battery. Maybe there's some showstopper I'm not seeing, but if offered this in the i3, I'd jump at it.

Ron

WOW you are way out there, drop in battery packs really? Cooling first thing that comes to mind and oh 240lbs of battery equal to 80 more miles when 450 lbs was required to get to 80 miles in the first place oh well so much for scientific knowledge, 200% improvement with drop in battery packs.

You know you can wait forever for improvements and just never do it! Now is the time to be counted if EV is to ever take off people need to stop waiting.

Just my 2 cents, I could die before it is worthwhile?

 

[fdl1409]

Hi Phil,

I am talking miles, not km. For example I did 151km with 29km remaining - that would be 112 miles. Miles driven plus remaining range always add up to at least 100 miles, up to 120. Will be less in winter of course, but even then I expect no less than 75 miles.
Driving country roads and urban mostly. Average speed not much above 30 mph, but that includes standing in front of red lights and very slow stop and go creeping in thick traffic. Negative factors for me are lots of hills up and down, with one charge I always have to climb much more than 1.000m. That reduces range somewhat. I also drive a lot of very short distances. For example today 26km ( 16 miles ) in 10 legs. And temperature here is mostly below optimum. We had only +1.6°C yesterday morning, 2.8° today, but warm in the afternoon. If conditions are right, warm weather above 20°C and longer distances with few mountains, I am sure to do more than 125 miles with one charge. Several people in Germany have reported up to 140 miles.

Of course you have to drive a little conscious, mostly EcoPro+ and most important always looking ahead and making best use of the kinetic energy of speed.

So far I did not use the REx intentionally, but yesterday it started the first maintainance run after 2.400km ( 1.500 miles ). Lasted 10 minutes.

Frank

 

[BrianStanier]

My range on country and urban roads is above 100 miles.

Frank

Hi Frank, I see you are from Germany and have an REX. Do you mean 100 miles, or 100 km? The official rating for REX is only 72-mile on EV .

Phil

Today I did 73 miles in our REX with 19 remaining driving 'normally' and including some serious Pennine hills. I believe 100 miles is easily achievable in a plain BEV i3,

 

[cove3]

My math is off, but the idea is what counts. Make it 8 briefcase packs at 50 lbs to get 70 . That plus 100 in the base model would equal 170.

In fact, with modular briefcase size plug in battery increments of 1 over the base 100 mile range, buyers could tailor their needs exactly...1 to n. Maybe even up to Tesla range. The weight per battery module would be what's fairly easily liftable. I should experiment with lifting a 30, 40, 50, and 60 lb briefcase.

If the cooling on the base is doable, maybe plug in batteries could be cooled similarly.

This is how rack mounted computer servers are configured. If you need more disk or memory capacity, you just slip in the amount you need.

Ron

 

[MikeS]

I would still prefer a Rex to a 100 mile battery BEV as the REX offers much greater flexibility.

 

[mindmachine]

I would still prefer a Rex to a 100 mile battery BEV as the REX offers much greater flexibility.

Ill second that preference with an amen! Big difference in capability with the Rex. I even go so far as to say I would take the Rex over a BEV with 200 miles battery pack.

 

[ultraturtle]

I would still prefer a Rex to a 100 mile battery BEV as the REX offers much greater flexibility.

Ill second that preference with an amen! Big difference in capability with the Rex. I even go so far as to say I would take the Rex over a BEV with 200 miles battery pack.

+1