Full EV Conversion

[retepsnikrep]

Now this is just thinking out loud at the moment. Comments and opinions welcome.

Having acquired a cheap manual car with a high mileage engine I've been thinking about a full EV conversion. I suppose with my EV background this is a natural progression for me.

Some project requirements for me would be.

150 mile range.
80mph top speed.
0-60mph <8 seconds (Now thats a big increase I know)

Lithium powered and AC regen drive.

Probably retain gearbox to allow ratio selection to match final motor choice.

Allow 200wh/mile which equates to a 30kwh pack for a 150mile range.

Overnight charge capability from a standard UK 240v 13amp socket. It would take about 10hrs to charge 30kwh pack.

So what could be removed and what would be reqd. Where would batteries go?

I suppose natural place for them is in IMA compartment with all standard gubbins removed.

Charger mounted down side of IPU compartment.

Controller and dc-dc converter etc mounted at front in engine compartment.

What voltage system should I use?

Siemens high voltage or Curtis low voltage?

Loads of info here on Gary's Insight Conversion.

My Electric Vehicles

Did he ever finish it I wonder?

And an excellent site for EV stuff and motors etc.

http://www.metricmind.com/

[Roger Crier]

0-60mph <8 seconds

Are you going Drag racing then?

[retepsnikrep]

I suppose I could buy another 50 x 40ah cells to add to the 50 I already have?

This would give a 160kg 14kwh 100 x 3.2v 40ah pack of about 360-385V when fully charged and 320V under discharge loads of upto 1C.

My BMS Master can cope with 128 cells in present form, but I would have to make another 50 slave boards!!

The 40ah cells I have seem quite happy to discharge at 1C (0.5C) would be better.
And they are rated for 120A upto 10 seconds.

So at 0.5C 20A discharge and 360v you have 7.2Kw, that's probably enough for about 50mph on the flat and a theoretical 100 mile range.

At 120A and 360v you have over 40kw or about 50hp which would give reasonable performance, especially with an electric motors torque curve and 0 rpm power delivery.

So a 10kw - 15kw 1hr rated AC motor would be plenty, as peak power would/could be much more for short periods.

Could the rear suspension cope with 160kg where the IPU compartment is? Assuming I got some one off uprated springs made to ensure ride height was correct etc?

[IamIan]

There is allot of information on the forums at

DIY Electric Car Forums Site Home

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There is allot of room in the rear IMA area once that is all removed ... and you also have 10+ gallons of volume from a gas tank area you also won't need.

If you were doing a more exotic wheel motor system you would still have most of the front end to use for batteries as well... but more conventional EVs are much easier and much less expensive.

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With the same type of batteries you are using now ... I think you would have no big problems fitting ~20 kwh worth in the rear area ... now weather or not you could fit ~30 kwh ... that might require a bit more careful planning.... but it should be doable.

If you are going to do this ... I would say you might want to look at changing the orientation of the spare tire ... if you have it upright ... it should still fit and still be accessible should you need it... then the rest of the space is for batteries and such.

The suspension would definitely need augmented.

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As for the voltage to run... higher voltages usually have less resistive losses due to lower current ... but if you choose a ~144V system ... you can reuse the DC-DC system from your Insight for conventional 12V operations.... A ~144V AC system is not that un-common... but to get that acceleration ... you will be pulling a health amount of amps.... but it is doable.

I guess it depends on whats on sale

[Mike Dabrowski 2000]

My approach will be to use a synergy drive with modified planetary assembly:
EV Insight with a Prius heart - MIMA Honda Insight Modified Integrated Motor Assist Tour De Sol

based on this nomograph:
Toyota Prius - Power Split Device
I should be able to hit 90+ MPH, and acceleration should be quite good with the lighter Insight chassis and all that torque, even without the transmission.

I hope to get to it this year, as the parts are already in the shop, just need batteries and time.
In theory a used synergy drive from a crashed Prius could cost a fraction of the metric mind system.
Good luck with the conversion which ever way you go.

[retepsnikrep]

Lots of good links and info as normal guys. Much to think about.

I also keep looking at the fact that I now have two spare IMA motors and know of a spare elsewhere in UK which would make three!

We have discussed the problems with making the IMA motors self suffcient and perhaps have two or three in parallel on a nice support of some kind.

I've found that driving the IMA motor at a much higher duty rate for long periods appears to have no effect. I've dumped my 40ah pack through it in less than an hour and it hasnt melted.

Mike Prius idea is neat, but I doubt I can get the prius innards over here for a reasonable price. Plus I allready have two spare motors and if you designed the motor/cradle/assembly system so another one or more could be added?

The Metric mind is the simple but expensive option, buy a nice neat 100kw water cooled motor and inverter, that will be $20,000 please. Hmm!

Can/could the Insight IMA drive packs be made to double up?

Or could/should I go for a low voltage (80v) system and use 200ah cells and the curtis AC 1238 controller and a suitable motor which is the cheapest option probably.


Or forget the whole idea for 5 years until batteries have moved on again?

I'm enjoying the phev and still got a fair bit of work to do on that.

[Mike Dabrowski 2000]

I got the inverter and complete synergy drive unit for a bit over 1K.
Microminds system is 20K.
My nephew just bought a brand new 2009 prius for $19500.

The synergy drive unit and inverter is water cooled, is made specifically for automotive use, has a built in differential and final drive reduction, forced oil bearing lubrication, and if I recollect correctly the combined motors put out substantially more power than the 100KW metric mind unit.

On the other approach, stacking the IMA motors should work fine, but you may need a separate power electronics package to drive each.
Like the idea of adding a second IMA drive motor on the other side of the clutch, but that would involve a real shoehorn of the engine and tranny into the bay, along with modified engine mounts. If it could be tucked in, one could cut the engine, switch motors to go pure EV with the battery system you now have, no e-wheel required.
I doubt if you would get your 8 sec 0-60 with even 3 IMA motors in parallel.

I have two IMA motors, on the bench, and one still mated to the engine of the green Insight, and one IMA power unit. One of the motors has been fitted with a drive shaft and I have the bearings to make it stand alone.
I will get that IMA motor so it runs at full power before attempting the same thing with the prius motors.

TMPNETOM (Two Many Projects Not Enough Time Or Money)

[Mike Dabrowski 2000]

Or we could just get one of these:
2009 Vectrix Vx-1 Scooter Debuts - Motorcycle USA

[Mike Dabrowski 2000]

I have been researching motor controllers, and ran into this.
Kelly High Power Brushless DC Motor Controller
The 144V 150A model is $699

It looks like it would connect right to the IMA motor, and has extra drive current over the stock system.

With good cooling, it is possible the IMA motor could do much better than 100A?
They have a 250A version. for $1K. That could possibily drive two IMA motors?

[retepsnikrep]

Interesting Mike.

Could you drive two motors in parallel with one controller? The regen voltage limit looks a bit low for the 120v version controller, scaling that up with the 144v one might not be enough overhead for the Lithium Cells.

Or would they need one each?

Even so $2000 for two controllers is a lot better than $20000.

Just need to get two or more IMA motors mounted together now!

They are nice and compact and weight 7lbs thought so quite interesting. For a performance vehicle 2x 144v 250A controllers driving 2 IMA motors might be best giving a theoretical 72kw power for 1 minute rating and a more modest 36kw cont rating.

We have discussed overdriving the IMA motors before and someone said they may not produce an increase in power due to magnetic saturation etc. i.e. motor may be developing all it's going to in stock setup.

Might have to do some clever forced cooling, water/air with two or more motors mounted together with No IC block absorbing the heat and being overdriven.

I might risk $1000 bucks later and buy one controller for some bench experiments.

If two IMA motors are locked together in exactly the same position and ditto the rotor etc then probably only one set of position sensors reqd for one controller. The 250A from a single controller split between the two motors seems a lot more reasonable and less likely to lead to motor failure.

If I got another 50 lithium cells and ran them in parallel with my current 50 that would give me the current capability (just) to drive the two motors at 250A for short periods. I would not need to make another 50 BMS slave boards either as each pair of cells could share one.

The peak power from a single controller would be about 48hp, not massive but possibly adequate.

The IMA motors have been designed for a 144v system so you may not be able to overdrive them without extra voltage as at 144v 10kw may be there limit. Even then as discussed above overdriving may not produce more power.