advice?

Technical discussion on converting internal combustion to electric
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Ed.
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advice?

Post by Ed. » Sat, 19 Aug 2017, 05:02

Hi, I'm new to this and need some advice. A few years ago I purchased a '98 four door Rav, with the intention of converting it when its current ICE got too tired, I figured it was the best type of vehicle as it was easy for parts, had the ground clearance, (I'm on the east coast of Tas), had a fair bit of room for batteries and hey it's a toyota. It has no rust, and the body just needs a good spray coat. Now my questions. Is it worth it, (we are off grid solar)? Is it the right kind of car? Good Books? What does the Tas Gov allow? If so should I use I drive motor/existing clutch, or mount 2 front and rear, or use the cv shafts and mount 4 drives directly? It's really hilly where we are so picking up charge is a big advantage I guess. Answers to any or all of these questions would be really cool. Thanks.

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reecho
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Re: advice?

Post by reecho » Sat, 19 Aug 2017, 08:55

Is this a AWD model? Manual or Auto??

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woody
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Re: advice?

Post by woody » Sat, 19 Aug 2017, 11:37

It's easiest to keep the gearbox and drivetrain; especially if the engine is transverse - you end up doing a lot less engineering.

I assume it's a manual RAV 4; not many convert automatics.

Toyota US Adid an all-electric RAV4 around 95/96 - not sure what parts they used it would be interesting to look at.

Worth it? Depends on how much you value your time / enjoyment of driving / achieving
Planned EV: '63 Cortina using AC and LiFePO4 Battery Pack

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Re: advice?

Post by Ed. » Sat, 19 Aug 2017, 19:47

reecho wrote:
Sat, 19 Aug 2017, 08:55
Is this a AWD model? Manual or Auto??
It's a partial 4wd, I think that is what was called awd, but it can be disengaged.

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Re: advice?

Post by reecho » Sat, 19 Aug 2017, 20:51

woody wrote:
Sat, 19 Aug 2017, 11:37
Toyota US Adid an all-electric RAV4 around 95/96 - not sure what parts they used it would be interesting to look at.
Tesla did the drivetrain for the 2nd gen RAV4 in the US..

https://en.wikipedia.org/wiki/Toyota_RA ... generation

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4Springs
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Re: advice?

Post by 4Springs » Sun, 20 Aug 2017, 06:29

Ed. wrote:
Sat, 19 Aug 2017, 05:02
Is it worth it, (we are off grid solar)?
This is a difficult question - I think we need more info!
It will use roughly 20kWh per 100km. Being off-grid you might want to carefully control when and how quickly you charge it? If so this will be more configurable with a home-made conversion than an off the shelf car. You may need to charge it elsewhere in the winter if you don't have the power - depends on how far you go with it. https://Plugshare.com shows a few places to charge on the east coast.
It will not be worth it from a purely monetary viewpoint unless you drive a lot of kms. Even then it would probably be better to buy a production EV.
Convert a vehicle because you want a challenge, or because you want a unique vehicle, or because you want an EV that you can tinker with and improve/repair yourself.
Ed. wrote:
Sat, 19 Aug 2017, 05:02
Good Books? What does the Tas Gov allow?
The code of practice for conversions is here: https://infrastructure.gov.au/roads/veh ... _ncop.aspx
Some things you need to consider are:
1. Keep within the GVM of the original vehicle and you will have less difficulty getting it approved. You need to make allowance for the weight of any passengers as well, the details are in the code of practice.
2. Batteries are heavy. Not as heavy as they used to be but still heavier than you'd like. As a rule of thumb, your conversion will weigh about the same as the original vehicle before you add batteries.
3. Because of 1. and 2., many people take out the rear seat of their conversion. Their vehicle then becomes a 2 seater, and they can use the space and weight saved to add more batteries.
4. What type of electronics does it have? Do you have to interface with an on-board computer? Others have done this, so it is not impossible but is an added complexity.
Ed. wrote:
Sat, 19 Aug 2017, 05:02
should I use I drive motor/existing clutch, or mount 2 front and rear, or use the cv shafts and mount 4 drives directly? It's really hilly where we are so picking up charge is a big advantage I guess.
You have listed these in increasing order of cost and complexity! So existing clutch and gearbox is the easiest, and means that you can use a smaller (cheaper) motor. Two motors would be pretty cool, and would be good if you wanted maximum power and traction for drag racing. But this would mean direct drive (no gearbox), which means more powerful and expensive motors and controllers. Others here might have more of an idea about 4 motors, but my understanding is that motors with the right rev range and power are not small enough to mount in this way.
Another option is to convert to two wheel drive direct drive (i.e. direct to the driveshaft for a rear wheel drive vehicle). Direct drive needs a fairly powerful motor and controller to get reasonable performance at low speeds.
DC motors/controllers don't regenerate electricity, but are cheaper to buy. AC motors/controllers do have regen, but they are more expensive, are more fiddly to get working satisfactorily and there are fewer options available. An AC conversion will go further on a charge than a DC conversion if you have hills. On the flat they will be almost the same if you drive sensibly.
Ed. wrote:
Sat, 19 Aug 2017, 05:02
Is it the right kind of car?
Think about what you want this car to do. How far do you want to drive? Over what terrain? At what speed? Do you want to race it? Then let us know so we can comment on it and give you an idea of what it might cost.
Personally I thought that I just wanted to drive about 80km in mine, and get up to 100km/h. But now that I have it, I find that the 100km range is much more useful than I had thought, and a bit more would be better. I also find that I take it to lots of car shows - something I never imagined I'd be doing! In my opinion older classic cars are good candidates for conversion - they can often take the weight, they don't have complicated electronics and computers to interface with, and you can have something really nice for your daily drive.

If you'd like to have a chat I and other AEVA members will be at MotorMania in Launceston on September 2nd. We'll have my DC conversion, an AC Handivan conversion and an Outlander hybrid on display. We'll also be at the Sustainable Energy Expo (also in Launceston) on September 16th.

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Re: advice?

Post by Ed. » Sun, 20 Aug 2017, 11:22

Ok, Thanks for all your comments, seems I wasn't so far from the mark when I thought about this before. Yep it's a manual, looks like Elon and Toyota, have done a lot of the work for me, I'll have to see what I can find out about their designs. Yep, charging will be an issue, our solar will need a big change, and even still there about three months it will be idle I guess. I thought about buying a newer one originally, but the computers put me off, and I like the idea of recycling, (embodied energy and all that). What I want to get out of it is about 130km/h, and decent acceleration with a range of about 160km. (Launceston and back from here) I figure some bright spark will put a charging station in Campbeltown soon enough. And I want it to be able to carry a decent load, at least fill the seats in a five seater. I've been looking for motors that would have torque to direct drive each wheel, but space becomes an issue due to the diameter required it seems. I read somewhere that brushless dc motors could deliver charge from the wheels. Now that I've at least got some feasibility sorted, complexity of the conversion is not a big concern, money always is, but I don't want it tomorrow, (well so long as we can still import diesel). More what I'm wanting is an efficient conversion, in a reengineered car. That does what I want it to, And I guess that includes what the Gov wants it to also.

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4Springs
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Re: advice?

Post by 4Springs » Sun, 20 Aug 2017, 14:57

Ed. wrote:
Sun, 20 Aug 2017, 11:22
What I want to get out of it is about 130km/h, and decent acceleration with a range of about 160km. (Launceston and back from here) I figure some bright spark will put a charging station in Campbeltown soon enough. And I want it to be able to carry a decent load, at least fill the seats in a five seater. I've been looking for motors that would have torque to direct drive each wheel, but space becomes an issue due to the diameter required it seems. I read somewhere that brushless dc motors could deliver charge from the wheels.
30kWh of battery in an AC conversion would get you around 160km on the flat at 80km/h in my estimation. From the east coast to Launceston though is not flat, so I'd say you'd need more like 40kWh for that trip. In LiFePO4 40kWh would be about 500kg and $16k. Check your GVM but I reckon this will be too heavy if you want a decent payload. There are other battery chemistries available, less kg and more $.
It might be more reasonable to go for 30kWh - this would probably get you to Campbell Town, depending on exactly where on the east coast you are starting from.

Brushless DC motors will give you regen, and are really efficient, and the controllers are cheap, but my understanding is that they are not available above around 90V. Probably something to do with the laws of physics. You'll need higher voltage than that - probably about 150V, or your cables will need to be unfeasibly large to get the power you need. An AC motor (or two) would be the way to go.
Rough cost estimate would be $30k in parts for a 30kWh conversion with LiFePO4. Add more $ for lighter batteries.

We're certainly planning a charging station in Campbell Town! Would be interesting to make a conversion that could take a DC fast charge...

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Richo
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Re: advice?

Post by Richo » Tue, 22 Aug 2017, 12:50

4Springs wrote:
Sun, 20 Aug 2017, 14:57
In LiFePO4 40kWh would be about 500kg and $16k.
400kg battery + 100kg battery box?
$16k sounds cheap too.
I would have guessed $20k+.
4Springs wrote:
Sun, 20 Aug 2017, 14:57
Brushless DC motors will give you regen, and are really efficient, and the controllers are cheap, but my understanding is that they are not available above around 90V. Probably something to do with the laws of physics.
Nah just the cheap high current fets.
At higher voltages the current drops off and price goes up.
Change to IGBT's and you need a different driver which costs more again.
Plus I suspect there is concern/liability issues about controller customers playing with a couple of hundred volts.
You dont get repeat business with dead customers :lol:
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