[gdirwin]

Formally introducing myself - I am an Electrical Engineer working in power
systems (wind farms, HVDC links, machines etc...) and specializing in
computer simulation. I also have a bit of auto-mechanic experience (I
have owned a 1975 F250 4x4 Highboy since 1983).

I have been a long time lurker here - thank you all for the phenomenal
support/information - this is a great site!

I am also fortunate to have my nephew (Derek) helping me on this - he is
18 and will graduate from high school this year. He has an aptitude for
taking stuff apart and fixing things, so this is a win-win situation. I enjoy
working with him, and his help will be appreciated. We hope to work every
Saturday and maybe one evening during the week. I have 2 boys (6 and 8)
who play hockey etc... so I am already pushing the limits of my spare
time - this will be a very slow build...


I recently saw Rob's (RKM) Red Miata - this lit a bit of a fire, so here we go...



My overall plan is to convert a relatively new vehicle (>2000) and to make
an EV that works just like its ICE counterpart in all ways - it will have
power everything, heated leather seats, full trunk space, air conditioning,
AWD etc... The plan is to demonstrate that you do not have to give up
anything to drive an EV (in fact it will be faster and better). Of course this
will not be a cheap build, nor will it be a super-efficient low kWH/kM build,
but it will be a very driveable car I will use as a daily driver in all seasons
(also more on this later).

I really only need about 50kM of range per day, but given winter
conditions in Winnipeg, and my desire to not push any equipment close to
its ratings, I will try to squeeze in more batteries/range than what is
really needed.





I finally bought my donor and started work:
2001 Toyota RAV4, 135,000 kM, AWD

I choose the RAV as it is a family car (would love a light 2 seater
convertible but with a family of 4 it is a no go), has some height/weight,
plus it has a history/reputation for EV'ers (stock RAV4 Ev etc...). also
considered a Ford Escape or Honda CR-V...

Everyone loves pics (although this is only the stock car so far):










Yeah - I know - the big sticker on the hood has to go. You should have
seen the car before - it had "all available Canadian Tire options". I bought
an OEM leather interior kit, as well as some carbon seat heaters for driver
and passenger with 5 position dial (I can hear the groans from all the EV
purists who have scrimped on weight/features etc... to get max range!)





My "REV4" EV Conversion Plan (please - all comments/suggestions/feedback welcome!):
- Warp 11 (or maybe even Warp 11 HV?) motor
- Zilla HV 1K or Soliton1 (not decided yet)
- SE or TS LFP batteries, probably 65*100AH (more if there is room - more on this later)
- keeping the 5 spd manual transmission, have bought a new clutch

Note that the motor and controller are likely more than the stock
clutch/transmission/AWD system can handle - I figure that equipment that
is rated for higher duty conditions but driven "soft" will last longer, not
heat up etc... (definitely an engineer talking - over design it). I love the
power however, so will start with the max controller amps limited, then
increase it until everything feels shakey, then back it down a bit...

If the Warp 11 HV motor receives good tests reports, then it seems like a
no-brainer for the cost - I will use a high voltage and as many batteries
as I can fit.

I plan to put the majority of batteries under the hood (on top of the DC
motor, manual transverse transmission and AWD transfer case). There
also is room under the rear of the car where the gas tank used to be (2
smaller boxes) - keeping the 4x4 definitely adds a penalty here as the
rear drive shaft cuts everything into 2. I do not want to fill up the
trunk/back seat with batteries though.

The batteries are a big pain (a low-height LFP battery that can stick under
the floor pans would be killer) - in reality I only have about 11" to work
with (which means TS or SE 100AH batteries, which are 8.66" high - once
you add the BMS, enclosure, insulation and heating pads, this doesn't
leave too many options. There are also the new SE 240Ah batteries (6.73"
high, 17.72" long, 2.8" thick) but that massive 18" length just won't match
up with the room I have in the car.

Horizontal placement of the batteries would also work, but I have been
told by SE that this is not recommended and would void warranty.

I think I can fit about 20kWH of batteries into the 3 boxes - I will pull out
all the junk in the way before ordering batteries though (maybe a
reasonable priced A123 deal will come along between now and then?)...

One non-logical aspect to my choices are using a 1000Amp controller with
100AH batteries - 5C would be a huge draw (perhaps too much?) so higher
AH batteries would be a better fit - they are too darn tall however (or too
wide for the 240AH) so I am somewhat torn/stuck. All suggestions
appreciated here - what would you do?




I am undecided on many other parts - will be deciding soon though. I will need:

- electric vacuum pump for power brake booster (Rob/RKM showed me a
pump that was enclosed inside of the vacuum tank - that made sense to
me!).
- electric power steering pump (no-one in Canada has a 2000-2005 MR2
Spyder pump - trying hard to find one in US for a decent cost - let me
know if you find one!)
- hydraulic pump/heater for interior heat (will keep stock heater core and
fan/controls - I don't like the idea of electric heaters inside the interior
heater core)
- 1000 Amp contactors/breakers/fuses?
- battery heating pads (it gets to -40 deg in Winnipeg for a few weeks
every year and I have to get to work!).
- BMS
- charger (I want a dual voltage 120/240 charger - 30 Amps would be lots)


I plan to pull the motor etc... soon (1 or 2 weekends from now) - I will
take careful measurements for the motor and batteries and make some
decisions then...



I have never done this (and definitely respect the people who have) so
please - all comments/suggestions appreciated!


Garth

[gdirwin]

First day of "work" (if you can call it that).

Took lots of measurements, played with sensors etc...

For the record, stock vehicle height (ground to fender) is:
- front: 31"
- back: 30"


Originally I was going to put resistors into all wiring harnesses to sensors
etc... (to fake out the ECM to think it was still connected to an ICE so the
Check Engine Light (CEL) would not activate) - I quickly gave up on this as
there must be >20 sensors on this thing - some have 4 or 5 wires (not
just simple resistive circuits). I will probably re-wire the CEL light to be a
trouble indicator from the controller or batteries (to be decided).

Along the way I got to use my ODBII code reader - I bought an
inexpensive ELM327 USB device - you connect one end to your computer
(drivers and software are a free download) and the other to the ODBII
port, and you can read codes, clear codes, see about 100 different engine
measurments etc... Highly recommended for the $50 it costs.


The only real sensor I have to deal with directly is the crankshaft position
sensor (CPS) - I believe this drives the tachometer, so I will have to
interface to the stock wiring harness in some way. Here is where the fun
begins:

Before I remove the gas ICE, I connected an oscilloscope to the CPS
signal (2 wires), then recorded what it looks like at different RPMs.
The scope is set for 5V per division, and 1 msec per division.

Here is what I saw (again everyone loves pics):
- idle (dash tach shows 750 rpm)


- 2000 rpm


- 3000 rpm


This translates into:
Tach RPM CPS Signal Ratio (CPS Hz/Tach Hz)
750 +/- 6V (peak), 425 Hz 34.0
2000 +/- 12.5V (peak), 1222 Hz 36.7
3000 +/- 12.5V (peak), 1777 Hz 35.5


36 seems like a nice round number, so this indicates that for every turn of
the motor, I have to generate a 36 Hz sine wave.

I was a bit surprised by the sin waves - I was fully expecting square
waves (perhaps PWM), which were either -12, 0 or 12V - has anyone else
seen this with a Toyota tach signal?

[efan]

these are some big pics....hard to see anything as they dont even fit in a 19" screen

[gdirwin]

Whoa - way too big - they are a bit smaller now...

[gdirwin]

36 seems like a nice round number, so this indicates that for every turn of the motor, I have to generate a 36 Hz sine wave.

I just noticed that the oscilloscope was set to AC coupling, which removes the DC component... I was still expecting a square wave which was either 0 or some other voltage... I think the AC coupling in the scope may also be distorting the waveform somehow...

I will repeat the test with the DC offset kept.



Google searching is amazing - I found this video explaining the different sensor types:
http://www.youtube.com/watch?v=RuIislTGOwA

I probably have a Hall effect type sensor,,,



I still think I need a 36 toothed wheel (or maybe 34?)... I haven't found a picture of the crank timing pully from this engine - it will look something like this (although this is from a different Toyota engine):


I am still digging to find out more about Toyota VVT - I think the CPS (or CKP) sensor also feeds the spark plugs (there are igniters directly above each cylinder) so I do not want to generate a test signal into the ECM when the engine is still connected - the tach test may have to wait until the engine is out.

[RKM]

Garth,

Congrats on the official start to your conversion! It almost sounds like a religious process doesn't it? I've been waiting for you to get this thread started. Let the journey begin...

Your's will be interesting to watch for at least a couple of reasons. First off, you are doing a high end build on a vehicle that will suit your family requirements. It sounds like you are prepared to spend the money and limit the compromise. Secondly, your background is electronics. I know you have ambitious plans for a tres cool control system interface.

Re. Batt selection

I don't want to sound unsympathetic, but the many of us who have wrestled to put batts in small cars are envious of the space available in an SUV. Had to deal with that first. I realize you still need to work with the dimensions available and that height is the real issue. My boxes are 13" tall from outside top of lid to the outside bottom. The cells are very nearly 11.25" to the top of the post. I have only about 1/4 of an inch to spare. The BMS takes up some space.

You had mentioned using 65 X 100Ah with a 1000A controller and pulling 5C. Maybe I missed it, are you intending two packs in parallel to get 200Ah which would give you 5C to drive the 1000A controller. If the 65 cells are in series, you would reach 10C to power 1000A (?). I know TS has increased the max surge rating to 12 or so, but I'd rather keep the draw as low as possible. My max C should be about 4.4 which is still plenty high. This string would also have a nominal voltage of 208, max 250. I'd be surprised if the Warp 11 will handle this high a voltage (Warp 9 rated to 170V). Are you planning to limit max voltage to the contoller?

If you opt for relatively low Ah cells, could you consider adding a cap bank to handle the brief high current load for acceleration?

I like those 240Ah, would make a great match for the controller. The height works so well, shame you can't fit the length.

Decisions, decisions. BTW, I appreciate your tongue in cheek comment defining spark plug!

Rob

[dimitri]

Since you aim for high voltage you will never pull 5C from the pack. 1000 amps controller means 1000 amps on the motor side, not the battery. If you go for 65 cells ( 208V nominal ) you will probably pull 300amps during acceleration, which is perfect 3C for 100ah cells. Cruising will be about 100amps, which is perfect 1C rate. Still, try to pack as many cells as possible to add voltage if you stick to 100 ah cells, to reduce current.

That sine wave is fine, I had same exact signal on my Mazda. You need 36 tooth wheel, which may need one gap ( one tooth removed ). See my Protege build thread, I have pics of the tooth wheel I made for RPM signal.

You will need a shop manual, get one, it has all these signals documented, helps a lot...

Good luck, seems like a very interesting and ambitious project.

I had same goals with my Protege, no compromise EV, turned out well, but being in warm and flat Florida helps a lot , you will have more challenges in Canada, but its all doable.

[gdirwin]

Thanks Rob/Dimitri:

The height restriction means low amp batteries - this pushes the higher voltage design. I agree that this is a problem for the Warp motors - I hope the Warp 11HV motor is available soon ( http://www.diyelectriccar.com/forums...ngs-35627.html) as this sounds ideal.

Once I remove all junk, I will take more accurate measurements and see if those 240Ahs will fit, which gives me a LV option...

I have the Haynes manual, but it is not great. I looked but am having problems finding the 2001 RAV4 factory service manual - Toyota has a TIS service that allows US citizens to download all for $15 for 2 days, but this is not available to Canadians...

Dimitri - I re-read your build thread and now I understand - interesting that yours had only 35 teeth. I will go to a wrecker and buy the 36 tooth crank timing sprocket as well as the stock crank position sensor. I plan to keep a rear shaft on the motor, and will use it for the A/C compressor (no A/C when stopped though). I will have to figure out what size of pulley to use (as the motor rpms will be higher than the stock ICE) and how to mount the toothed wheel to the pully...

Thanks for the feedback - much appreciated!

[Dave Koller]

http://www.diyelectriccar.com/forums...urn-30356.html

Different car - of course - but thought you might like the musings about the various sine to square waves of my Saturn... Nothing so simple!

[gdirwin]

Thanks Dave - I see you have been there - done that. I will plan to keep the ECM and tach as-is - hopefully I can add the stock crank sensor and toothed wheel to the rear shaft, and it will all work...