# Planning a 2004 3dr Toyota Echo conversion



## madderscience (Jun 28, 2008)

hi chrisale-

A toyota echo is a good conversion candidate, and some have already been done. You can look here: http://www.austinev.org/evalbum and search for several examples of toyota echo conversions.

to get daily 80km (50 miles or so) range with significant hill climbing puts you into lithium territory, but it is quite doable with lithium.

You can safely assume probably about 250 wh/mile on average for battery-to-wheels efficiency so that means you need a usable battery pack capacity of 15kwH bare minimum to meet the range under ideal driving conditions. This is pretty achievable. (100Ah at 156V), but for more margin for cool weather and running the heater and having 4 people in the car going over the pass, go to 160AH or even better 200AH at 156v. (23KwH or 30KwH or so) 

If you haven't found any AC vs. DC debate on this site, well you haven't looked close enough  but basically when it comes to options available for a conversion, DC is cheaper and simpler, and can be built to be very powerful. AC is more sophisticated, more reliable, slightly safer, (less risk of a runaway controller) and offers regen capability which is definitely a good idea on the descents off your mountain pass. AC can be considerably more expensive than DC however depending on the system you get, and the peripherials (a much higher voltage battery pack) can make other parts of the conversion more expensive too. Basically IMHO the arguments boil down to AC is "better" but DC is still really good for the typical use case. if your 400M hill is steep enough that you ride the brakes if you coast down in neutral, then the safety aspect of the regen (to replace engine braking) should not be underestimated.

A toyota echo has a transaxle so the best direct drive solution would be an AC motor driving a modified tranny with only 2nd gear (ideally removing the rest of the guts, converting it to a fixed gear ratio around 8:1 overall) or just replace the whole unit with a single ratio gearbox AC drive (see metricmind.com for examples)

If you went DC you would still want the transmission as you would need at least 2nd and 3rd gears. DC direct drive is typically done with a powerful motor and a powerful controller (think white zombie) and only the differential gear ratio (around 4:1). 

If you are concerned about the high mileage transmission, rebuild it or find one with less mileage during the conversion process.

Canev as far as I know is a pretty reputable organization. You are also not that far from vancouver and VEVA (vancouver electric vehicle association) which is a very active electric vehicle group.

Enthusiasm, determination, patience and willingness to learn are probably the most important traits if you don't have a lot of previous electrical or automotive experience. You might try doing an E-bicycle conversion just to get an idea of the basic steps involved on a much smaller and cheaper scale first. It all really does just scale up from a bike to a car.

with both a decent sized lithium battery pack AND and a high voltage AC drivetrain you are probably looking at a conversion closer to $25-30K USD at least at best known retail prices stateside. you can potentially knock a few thousand off for DC, but you lose regen in that case. If you find some or all parts used you can save significantly. 

Good Luck.


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## tomofreno (Mar 3, 2009)

Hi chrisale,

I recently converted a Suzuki Swift using the AC50 motor, which is the AC motor canev is offering for sale. The build thread is under the conversions forum, titled "SwiftE". It performs very well and would exceed your 55mph requirement. You could get similar acceleration and range from a 8" series DC motor/controller if the controller could supply similar max current (550A), and it would be maybe $1000 or more lower cost, but would not have regenerative braking. There are lots of discussions on AC versus DC here and on other ev sites. The first thing I would do is read, read, read. I spent a year researching info, checking out suppliers, and doing calculations before I ordered anything.


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## chrisale (Dec 9, 2009)

Thank you both for your replies!



> A toyota echo has a transaxle so the best direct drive solution would be an AC motor driving a modified tranny with only 2nd gear (ideally removing the rest of the guts, converting it to a fixed gear ratio around 8:1 overall) or just replace the whole unit with a single ratio gearbox AC drive (see metricmind.com for examples)


OK, this is the kind of answer I was looking for. I will go check that out. The gear box just seems unnecessary and potentially problematic both in a maintenance as well as a usability sense to me for an electric car so when I do this I want to do it right for the long term.



> You can safely assume probably about 250 wh/mile on average for battery-to-wheels efficiency so that means you need a usable battery pack capacity of 15kwH bare minimum to meet the range under ideal driving conditions. This is pretty achievable. (100Ah at 156V), but for more margin for cool weather and running the heater and having 4 people in the car going over the pass, go to 160AH or even better 200AH at 156v. (23KwH or 30KwH or so)


I need to spend more time understanding the math of it all. This is the kind of explanation I've been looking for as well. And I like the progression. My understanding is that the range/speed is generally up to the battery packs and the controller. So I could start out with say 100Ah at 156V to start... then as time and funding allows, move up the scale until we get to 200Ah.



> if your 400M hill is steep enough that you ride the brakes if you coast down in neutral, then the safety aspect of the regen (to replace engine braking) should not be underestimated.


If I was in neutral I would most certainly be riding the brakes. Am I understanding correctly you're saying the regen would effectively act as an engine brake to slow the car as it was going down the hill (this makes sense in my head, but just checking). 



> I recently converted a Suzuki Swift using the AC50 motor, which is the AC motor canev is offering for sale.


Perfect! I will go to to your thread to look for a price list as well. I've been researching/looking at this stuff for probably 2 years on and off now, and the hardest thing always seems to be finding places that actually state prices up front! This website has been a godsend in that department!

Thank you again all. My goal at this point is to be driving my new conversion by this time next year. So that's the plan....


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## tomofreno (Mar 3, 2009)

> Am I understanding correctly you're saying the regen would effectively act as an engine brake to slow the car as it was going down the hill


 That is correct, and the main reason I wanted electric braking. I like the regen current to the cells also, but I expect it doesn't add that much to my range since I don't do a lot of stop and start driving. I wanted electric braking to hold the car back on hills, just like I use an ICE at to hold a vehicle back rather than the brakes. My AC50 and controller came with a fixed setting for regen which is low. I am now looking into buying a programmer for the controller to reprogram and add an external potentiometer to control the amount of regen. I think they should be sold this way, not at some fixed value.


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