Project Land Yacht (BMW 5-series EV conversion)

[jackbauer]

Firstly Merry Christmas to all Secondly I'd like to introduce the new project that i have christened the land yacht! Donor vehicle is a 2001 BMW 520I E39 5 series. Equipped with a 6 cylinder 2.2L petrol engine that has a few minor problems This is going to be replaced with a 13" rebuilt forklift motor , 1200amp controller , 15kw 3 phase charger and a pack of 60 CALB 180Ah grey cells. Let's see what happens ........

http://www.youtube.com/watch?v=WZTtci674fE

http://www.youtube.com/watch?v=CPY4kvVpn6s

[jackbauer]

Bit more progress .....

http://www.youtube.com/watch?v=iXhOBl0xljw

[Daox]

Woo, sounds like a fun project. I'm anxious to see how the CALB grey cells work out for you. Everything I've heard about them is that they're a very nice battery. Looks like with that many you should have some pretty good range too. I'm guessing 80-100 miles.

I also gotta laugh at the 5 series being called a land yacht. Many here wouldn't even consider anything smaller...

[mechman600]

Brilliant! I will be watching this.
I love Beemers. I want to convert a 3-series in the worst way.

[Daox]

I take it you went with a clutchless system due to the amount of torque you'll be transmitting? Do you have any solutions for quicker shifting?

[cRiPpLe_rOoStEr]

I also love Bimmers. But if I would ever consider to convert one to all-electric drive I'd consider to remove the gearbox and use one of those reversible motors, to take some weight away and eventually leave more room for a bigger set of batteries.

[mechman600]

Originally Posted by cRiPpLe_rOoStEr

I also love Bimmers. But if I would ever consider to convert one to all-electric drive I'd consider to remove the gearbox and use one of those reversible motors, to take some weight away and eventually leave more room for a bigger set of batteries.

Unfortunately, direct driving a car requires a very large motor - 11" or 13" or larger - and the increased weight offsets the weight savings of ditching the transmission. One possibility is two 9" motors end to end and parallel/series switching them to achieve both the required start off torque and high speed.

The beauty of converting RWD cars is that the transmission is out of the way to begin with, leaving much more room under the hood for other goodies. Ridding the engine compartment of a motor (moved to the ex-transmission's spot) doesn't really gain a whole lot.

In all my research, it seems that the only proper solution is to keep the transmission. Even though electric motors have a flat torque "curve" (line?) down to almost zero RPM, they do not have a wider effective RPM band than gasoline engines. One gear is never enough, unless of course you spend big money on high end AC componentry. But even the Tesla roadster has two speeds.

[cRiPpLe_rOoStEr]

Originally Posted by mechman600

Unfortunately, direct driving a car requires a very large motor - 11" or 13" or larger - and the increased weight offsets the weight savings of ditching the transmission. One possibility is two 9" motors end to end and parallel/series switching them to achieve both the required start off torque and high speed.

13"? Check

An electric-drive usually is a good field for experiments and improvements in the course of the project anyways...

[Xist]

I do not even understand what you are doing, but I wish you the best of luck!

[mechman600]

Originally Posted by cRiPpLe_rOoStEr

13"? Check

Man....looks like you are set. When is your EV build starting?