Electric MG Midget Conversion

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I have just past 2,000 miles on my converted MG Midget. I've been working through some weight and drag reductions efforts, and it is starting to pay off. I just measured my full range (LiFePo4 batteries down to 2.7 volts) at 112 miles. I have a 19.6Kwh pack, (38) 160Ah cells. I'm really at this site to investigate more ideas for drag reduction, but I thought I post here for people interested in EVs. I have a site that discusses some of the things I've done like a lightened flywheel. I also have a section on measuring the Cd of the car, and using a GPS to calculate your energy use on a measured route. I'm happy to discuss any of this as well, so please reply here, or contact me if you have any questions. you can see my site at (Sorry I can't post the actual site I'm too new to the forum) it is electricmgmidget.com

[Daox]

Cool car. What do you have for a drive system in it?

Yeah, some aeromods will help out but I'm guessing you don't want to mess with the styling of the car too much. Blocking the grill is a good start along with adding a belly pan.

[drmiller100]

cool car!
you should be very proud of what you have done!

how much are you willing to change the "look" of your car?

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I have a Series wound DC motor (Warp 9 Impulse) and I kept the transmision. If you look at the site electricmgmidget.com you can see much more details about the car.
I have most of the front grill blocked off already. I read on this site that just blocking off the airflow, even if it behind the main features of the grill works. I'm planning on trying to do a belly pan at the rear of the car. Midgets have an almost perfectly flat bottom through the middle of the car. The rear axel area is where I'm hoping I can get a measureable improvement. I can measure it with my controller telling me my power usage while I drive. When I get any data I think is valid, I'll be sure to post it here.

[mort]

All about this electric MG by Frank Bernett is really a fine site, everything is wonderful. But have I been under a rock or something? This watch!
I've been recording the speedometer on video, which is a bit of a hassle, and then manually transcribing. But man! And phone apps that do the same thing. Does anybody use them? Is there a good file format. Sheesh!
-mort

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mort,

I have had this site up for about 2 months, and I haven't had anyone comment on the idea of using the GPS running watch to record your speed so you can calculate your Cd and Crr. I was wondering when someone might notice it is a cool idea. Since many phones now have a GPS built in, I figured they could do it too. Some running sites have a way for people to track their runs with their phones so I think it can be done. Did you check out the article on measureing your energy use for your route? I had used the running watch to record the distance to work so I could calibrate my odometer. Then I realized that it had all the information to calculated your energy use from speed, acceleration, and altitude change. (the altitude change is not very accurate in GPSs , so be careful.)

Frank electricmgmidget.com (a few more posts, and I can add this to my signiture)

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Originally Posted by drmiller100

cool car!
you should be very proud of what you have done!

how much are you willing to change the "look" of your car?

I don't want to alter the look of the car that much. I added some tarpaper covers that cover the rear axel. On Midgets there is a large area for the rear axel that breaks up a very flat bottom. I wanted to extend the flat bottom past the rear axel. So I have the tarpaper attached to the frame in front of the axels, and then I attached the tarpaper to some wood I strapped on the bottom of the axel. The whole thing has to float with the axel. It came out pretty well. That blends the bottom out to my rear battery box. The box has a flat back, and that is where I need advice. I was going to try to blend it up to the rear bumper, but after reading on here last night, I’m not sure that is the right way to go. It sounds like I want to extend the batter box bottom back, but only at a 2.5 degree angle from the bottom surface. When the extension gets to the rear bumper simply end it?? I can take pictures of the rear end if anyone here is willing to comment on what I should try. I did try to measure the effects of my tarpaper mod, but the air temp was 55 deg, and it was very windy. My test route data was worse than my last run when it was calm and 80 deg. For me, I measure in watt-hours/mile, which is actually a force unit (drag). It was 8% worse. Today’s commute to work was back to what I have gotten before, and again it was colder than before. I was hoping to see an improvement.
So if there is any interest in helping me, please reply. Thanks

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Well, I'm about a week away from my 1 year anniversary of getting my Midget on the road. I'm also 250 miles shy of 4,000 miles. (Now I know how much I drive this car every year) I've driven the car almost every day, in winter as well as summer. I've had no issues at all with the car. It's almost boring. Every few days when I get close to 50 miles of use I plug it in over night. The next morning the BMS has balanced the pack and shut off the charger. I turn the key, and my fuel gauge reads full again. I've driven it top down all summer, which is why I really like Mg's. The one disappointment I have is no one knows it's electric. I was hoping for a little more notoriety, but that hasn't happened.
So while it is expensive, electric car conversion components have gotten to the point of allowing people to build reliable cars. Li-on Batteries are now available, and can be trusted to deliver their claimed specs. Controllers are very good now, and getting better all the time. There are any number of good choices in motors. I hope people can see what I've done and get inspired to build their own cars. It isn't easy, and I hope that if you do choose to try this you have some experience of working on cars. Even though the components have matured, putting them all together is still very custom.

[Daox]

Originally Posted by fb_bf

I've had no issues at all with the car. It's almost boring.

Haha, me and Darin (MetroMPG) were just talking about this the other day with my battery electric lawn mower conversion I did. He mentioned I never mention it anymore. Well, there isn't much to mention. It works like a charm, zero maintenance, its wonderful.