Electric Miata/MX5.

[neptronix]

I heard that the NA miata had something like a 0.38 cD..

Anyway yea, i fit in a MR2 just fine, so i might go with a generation 2 model. The gen 3 model is nicer in every way, but a little more cramped and with worse visibility.

 

[Hillhater]

If I recall, the miata has a pretty bad Cd, right?

I suspect any soft top will have a "less than optimum" .. Cd ...especially with the top down !

 

[jonescg]

I've been helping a friend with his Toyota MR2, http://www.evalbum.com/3229
It's a good car but the battery space is seriously limited. He's running 45s LiFePO4, 70 Ah CALBs. The only way to fit enough cells was to place them under the car where the exhaust used to be.

With the best cells money can buy, you might have a good conversion, but for affordable lithium, you'd be quite limited for range.

 

[neptronix]

Thanks for the heads up, Jones. I didn't consider that at all. I guess i don't have any conception of how big those ~100whr/kg lifepo4's are. Maybe i'll go back to my Tercel idea

 

[neptronix]

Hey, how's the car running?

 

[halcyon_m]

Yeah, I'd like to know as well. Did the lipo's last at all?

 

[Jozzer]

The car was dismantled last summer and parts sold - but all the Lipo live on. Some was refitted to another electric car (the owner had killed half his pack by overcharging it with a homemade charger!), the rest is boxed up here to be refitted to one of my motorcycles later this year..
Motor and controller also lasted well and are on their way to being fitted to an RX8..

 

[Drunkskunk]

So what happened to cause you to break it up? did it do poorly, was there something else?

 

[Ypedal]

Was there ever a video of this car running hard ? .. i went back looking but have not managed to find any

 

[Jozzer]

The car performed great - just I have limited use for a 300HP+ car that can only fit 2 people. I also moved home and business - so decided to free up the resources and build a bigger car next year!
I have as much fun building EV's as I do using them, so it wasn't a huge loss..

Sorry no video, we did try a few times but was never able to catch the spirit of the car. Not as easy as filming ebikes! Those who came for a ride in it will never forget it however

 

[h0tr0d]

The main thing is to CHECK ALL PACKS VERY CAREFULLY. I don't mean just give them a discharge and charge - that's not enough. Our testing process is to cycle the packs twice looking for any anomolies (high IR cells or low capacity - 3-5% of packs will show faults here), then put them on the shelf for 6 weeks minimum and repeat (often a cell will have a higher self discharge rate than it's buddies and needs to be weeded out so it can't weaken your whole pack - another 2-3% of packs will be found faulty here).
The bigger the pack, the more careful you must be to have all good cells. So far, not a single pack that has passed this testing process has failed in use (out of perhaps a couple of thousand).

The car was dismantled last summer and parts sold - but all the Lipo live on.

Awesome, pure gold right here!

Did you charge them to 4.2V or less? And low voltage cut? Estimated cycles?
Thanks!

 

[Jozzer]

Yup charged to 4.2V, most often discharged less than 75% though a few full cycles. Probably around 180 cycles in the 9000 miles it did. Daily use at 14C, 1000A of torque was hard to resist

 

[riba2233]

Sup, did you ever do another conversion?

 

[jonescg]

Would love to know how Steve is going! I can comfortably credit him with inspiring me to build my first electric motorbike.