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Discussion Starter · #1 ·
Hello, i kinda fell into the whole EV conversion rabbit hole because i got my driver license now and am looking for a car.
With the rising gas prices in my country, the road taxes on diesel/ gas & car weight. I got kinda interested in cost reduction.
going electric would mean no gas, no roadtaxation on top of my alreadying having a 75% insurence discount from 8y of driving motorcycle.

But to be honest, i'm a construction engineer, not a mechanical engineer, so i'm unfamiliar with torque/horsepower stuff but do know a bit about kwh/kw/volts/amps/ simple electrical stuff.
I'll probably have to dive into some more theory to understand what i'm doing. But was wondering something.

I'm kinda biased towards toyota cars and personally i just really like the old toyota generation 2 cars:
be it the 3-door variant or 5 door variant .

I understand enough physics to know aerodynamic design matters, same as weight for how much energy you need to get a car driving and maintaining that speed.
but i'm not sure what's considered high or low or acceptable for all this.
so based on a curb weight of 1100-1300kg (2425,085-2866.009lbs) of the rav4 cars.
and knowing i'd probably wanna have enough range to drive 250-300km (155,34-186,41 miles)
I think in most cases i'd drive under 100km a day (63 miles) but would like the extra buffer for trips.

  1. What should i be looking at?
  2. Are these old toyota rav4 models suitable for ev conversion?
  3. How much weight do you lose from taking out the tank, engine parts on average?
  4. Would I be close if i thought i needed 42kwh in tesla batteries? (8modules?)
  5. with 8 modules you'd gain 200kg + an engine can weigh 75kg, would the car become lighter or heavier (if taking out the old parts)?
  6. how easy/hard is it to fit 8 modules in the car?
  7. does reducing wheel weight matter? what about wheel diameter?
  8. If i drive the car once or twice a week, is it worth attaching a solar panel on top? (i heard it's not worth it for daily commute as it only charges 3kwh on a good day? but if the car charges for 3 to 7 days in between wouldn't it start to matter more? the car will be parked outside 24/7. and does it matter for passive systems like car security/alarm systems/radio/ac?
  9. is it easy to upgrade battery capacity in the future if id wanna increase the car's range?

    Any insights are welcome, as while i might not immediately commit to EV conversion, its good to know if you atleast have a car that has the capacity/capabilities to do it.
 

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Discussion Starter · #3 ·
There was a RAV4 EV in 2012...
Oh, i heard of that one yeh, but there are almost none available in my country and been eyeing places for the last 4/6 months now.
the one i did see costed 22k+ euro

While an old rav4 from 2001/2003 would be around 3-5k by itself. and could be the cheaper alternative.
 

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You just kicked the can down the road...the conversion has been done by the factory. You have an electric the day you buy it.

So you allegedly now have a cashflow issue. Buy your ICE RAV4, then sell it and buy a RAV4 EV. If you don't, you will spend the same money and not have a car for two years to drive. If ever...

You'll need to buy a second car while doing the conversion and pay for the conversion parts. Cashflow insanity.

You can't argue your way out of buying a car that's already available as a factory EV unless you have some issues to address that the factory EV doesn't have. Even then, you need to afford to buy three cars vs one Rav4 EV.
 

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Discussion Starter · #7 ·
You just kicked the can down the road...the conversion has been done by the factory. You have an electric the day you buy it.

So you allegedly now have a cashflow issue. Buy your ICE RAV4, then sell it and buy a RAV4 EV. If you don't, you will spend the same money and not have a car for two years to drive. If ever...

You'll need to buy a second car while doing the conversion and pay for the conversion parts. Cashflow insanity.

You can't argue your way out of buying a car that's already available as a factory EV unless you have some issues to address that the factory EV doesn't have. Even then, you need to afford to buy three cars vs one Rav4 EV.
Do wonder some things on that 2012 EV model:

  1. Would the batteries be as good? how much would they degrade if they are from 2012?
  2. how about the weight to capacity ratio of the batteries?
  3. how was the electric motor technology back in 2012? did the efficiency stay the same to modern third party electric engines?
  4. the car seems a lot heavier too at 1829kg, while only having 166km range. this sounds like a problem.
  5. It looks like it only has a slow charger port, and saw it described as needing more than 24h to fully recharge.
if interested in the 3 door version, it was discontinued after 2005 or so, so there doesn't exist a modern variant, nor an electric version.
Wouldnt a DIY approuch save weight, while improving range, efficiency & recharge rate compared to that 2012 ev model? or would that be too optimistic? i'd love to hear your analysis.

offnote: seems that standard ev model rav4 also has around 42kWh battery capacity, but the range is 166km instead and has 25hp more compared to standard older models needing 115kW instead of 92kW. (i guess that has to do with the higher weight)
 

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Do wonder some things on that 2012 EV model:

  1. Would the batteries be as good? how much would they degrade if they are from 2012?
  2. how about the weight to capacity ratio of the batteries?
  3. how was the electric motor technology back in 2012? did the efficiency stay the same to modern third party electric engines?
  4. the car seems a lot heavier too at 1829kg, while only having 166km range. this sounds like a problem.
  5. It looks like it only has a slow charger port, and saw it described as needing more than 24h to fully recharge.
if interested in the 3 door version, it was discontinued after 2005 or so, so there doesn't exist a modern variant, nor an electric version.
Wouldnt a DIY approuch save weight, while improving range, efficiency & recharge rate compared to that 2012 ev model? or would that be too optimistic? i'd love to hear your analysis.

offnote: seems that standard ev model rav4 also has around 42kWh battery capacity, but the range is 166km instead and has 25hp more compared to standard older models needing 115kW instead of 92kW. (i guess that has to do with the higher weight)
second gen (2012) Rav4 EV was using a drivetrain supplied by Tesla. That drivetrain was cobbled together out of Model S and Roadster components, obviously from that period, so performance / longevity would be on par with Tesla vehicles of that time.
 

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Batteries from 2012 would not be in the best shape most likely.

A DIY version could very well be more capable than the RAV4 EV, that car was not far off from a DIY anyways (tesla parts cobbled together to produce a small number of units).

Cost is another story however. An EV conversion is almost never cheaper than just buying a used factory EV.
 

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Batteries from 2012 would not be in the best shape most likely.

A DIY version could very well be more capable than the RAV4 EV, that car was not far off from a DIY anyways (tesla parts cobbled together to produce a small number of units).

Cost is another story however. An EV conversion is almost never cheaper than just buying a used factory EV.
I don't know how much NCA cells degrade from the age alone, but let's consider this. That vehicle had a range of roughly 100mi on a charge. I've recently seen a 2014 Rav4 EV with 40,000mi on it - that would be 400 full cycles. Those cells should be able to take a couple of thousand cycles pretty well. Additionally, there was no ChaDeMo adapter on most of them, so they all were charged rather slowly without stressing the cells.

Even though the drivetrain was "cobbled together", it was still properly engineered and built out of parts Tesla engineered for their other vehicles. There is no way 99% of DIYers can match that.
 

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I don't know how much NCA cells degrade from the age alone, but let's consider this. That vehicle had a range of roughly 100mi on a charge. I've recently seen a 2014 Rav4 EV with 40,000mi on it - that would be 400 full cycles. Those cells should be able to take a couple of thousand cycles pretty well. Additionally, there was no ChaDeMo adapter on most of them, so they all were charged rather slowly without stressing the cells.

Even though the drivetrain was "cobbled together", it was still properly engineered and built out of parts Tesla engineered for their other vehicles. There is no way 99% of DIYers can match that.
Fair point. Battery technology has come a long way though, and a DIYer can certainly convert a gas RAV4 with more than the 103 miles of range of the OEM (2014) variant.

Toyota also wasn't even pushing the limits at the time, as the RAV4 EV was primarily a compliance car to meet California fleet emissions standards.
 

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Fair point. Battery technology has come a long way though, and a DIYer can certainly convert a gas RAV4 with more than the 103 miles of range of the OEM (2014) variant.

Toyota also wasn't even pushing the limits at the time, as the RAV4 EV was primarily a compliance car to meet California fleet emissions standards.
There are no magical unicorns that came to exist since 2014. There are EVs that achieve significantly more range because of the classic reasons - bigger battery packs, better aerodynamics, lower overall weight, and in exotic cases high efficiency motors. Nearly none of these factors will apply to a home conversion of a gas vehicle. So if anything, I would expect a DIY conversion to do WORSE than 103 miles.
 

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Per wikipedia, the battery pack in the RAV4 EV weighed 840lbs and had a total capacity of just 41kwh. It's a NiMH pack, less energy dense than today's (mostly) lithium packs. Production technology and scale have improved and have made lithium cells economical enough for use in EVs.

Throw in 12 Tesla modules from a recent LR model S/X and I'd expect range to be 160+ miles.
 

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Per wikipedia, the battery pack in the RAV4 EV weighed 840lbs and had a total capacity of just 41kwh. It's a NiMH pack, less energy dense than today's (mostly) lithium packs. Production technology and scale have improved and have made lithium cells economical enough for use in EVs.

Throw in 12 Tesla modules from a recent LR model S/X and I'd expect range to be 160+ miles.
First of all, there were two generations of the electric Rav - first one indeed used a NiMH pack. Second generation is the one with the 41kWh Lithium pack you're describing. It's all on that same Wikipedia page, you just got to go through the entire page :) I don't know where you're going to throw 12 Tesla modules, but you would need approximately 72kWh battery pack to move that vehicle 160miles.
 

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Ah, you are right. I'll blame reading on my phone lol...

Regardless though, 840lbs for 41kwh of capacity is far worse than more recent vehicles. A model S pack weighs 45% more but has 150% more energy capacity.

12 modules shouldn't be too difficult. I have 10 in a Ford Escape, without compromising interior space. Throw a couple in the trunk and you'll have no issue with space.
 

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Ah, you are right. I'll blame reading on my phone lol...

Regardless though, 840lbs for 41kwh of capacity is far worse than more recent vehicles. A model S pack weighs 45% more but has 150% more energy capacity.

12 modules shouldn't be too difficult. I have 10 in a Ford Escape, without compromising interior space. Throw a couple in the trunk and you'll have no issue with space.
This 40kWh pack is built out of 18650's, just like the Model S pack. It will be slightly heavier than battery packs made out of pouch or even prismatic cells due to large amount of "packaging" material, but your comparison to a Model S pack is not apples to apples. Each factory battery pack will have a bunch of components that take a certain amount of weight independently of the capacity. Then there also will be some things that will scale non-linearly. Building your own you can of course take shortcuts, and omit things like the enclosure for the entire battery, especially if you're willing to sacrifice the interior room instead of mounting it under the vehicle. Then from the capacity standpoint (and contributing to weight) it really depends on the era of your Model S donor - it is likely that capacity of the cells has changed slightly over the years, but if you go back as far as 2014, you'd likely get the same ones that were used for Rav4.

I see that for Model S 85kWh pack is 6216 and 7104 cell counts are cited in different places. Which one are you looking at for comparison ?
 

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Exactly. Cells would be the same (or at least similar), but packaging is not. The crux of my argument is that final (module level) energy density has improved, even if improvements in cell capacity have been negligible.

6216 is the 14 module variant, and 7104 16 module I believe.
 

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I see that for Model S 85kWh pack is 6216 and 7104 cell counts are cited in different places. Which one are you looking at for comparison ?
6216 is the 14 module variant, and 7104 16 module I believe.
That would make sense: 16 of the 444-cell modules for 7104 cells and 85 kWh (from the Model S 85D); 14 of the same modules for 75 kWh (from the Model S 75D).
 

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I would think you could get a EV from a neighboring EU country. Converting a car can be "cheap" until you get batteries. Do some more reading on here and you will see. People do it by choice, not for cost. Just like any automotive build or customization. Check this build, A year ago he was still driving it.
 
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