[Goosoid]

Hi there,

I was wondering whether it would be possible to convert an old hybrid, like a 1999 Prius, to a full EV. With the price of 1998/1999 Prius getting down well below $10k or even $5k it seems a viable option economically.

My thinking was that it already has an electric motor (though maybe it is not powerful enough??) so wouldn't it just be a matter of replacing or supplementing the existing batteries to extend the range? I realise it may not go that fast, but as a city car it wouldnt be such a big deal if it only did 50km/h.

I know the new Prius models can go up to 15kms in EV mode and I think it is about the same for the new plug ins.

However, I looked on Google and this topic doesnt even seem to be discussed so I assume there are good technical reasons this cant work?

 

[Sunking]

However, I looked on Google and this topic doesnt even seem to be discussed so I assume there are good technical reasons this cant work?

I don't know about that. I think it is just because no one has tried yet, or for th every view that might have done it has not posted anything.

Heck with the sales of the new Chevy Volt's, all two of them, I bet if you are patient you can buy a new one for less than $10,000 when Chevy decides to dump it. Then you can strip the engine and gas tank out, install more batteries if you want. Or wait a year and track down the two buyers and I bet one of them will be thrilled to get a low ball offer to cut their losses and run.

 

[Hemon Dey]

My thinking was that it already has an electric motor (though maybe it is not powerful enough??) so wouldn't it just be a matter of replacing or supplementing the existing batteries to extend the range? I realise it may not go that fast, but as a city car it wouldnt be such a big deal if it only did 50km/h.

You would need to know a thing or two about the Toyota system and how to get it to work without the ICE running. You could perhaps fake the sensor signals connecting to the car's ECU, but this will require you know what nominal levels those signals are and how to design a circuit to emulate those signals without the engine present. Somebody told me once that if you pulled the injector cables off the engine, the ECU will think the engine is running but really no fuel is going to it - hence you can run the car on EV mode. The main problem is that the battery pack is too small, so will not go very far.

I know the new Prius models can go up to 15kms in EV mode and I think it is about the same for the new plug ins.

My 2005 prius can go on EV mode only up to 45km/hr - other models can go up to 58km/hr before the engine kicks in. To extend the range of EV only mode you will have to place in a larger battery pack - there are many of these packs available now ranging from high voltage packs to replace the primary battery in the Prius, to a low voltage 48V secondary pack which has a low voltage to high voltage DCDC converter - but it really on "trickle" charges the battery at 5kw. The latter might be enough if you wanted a run about car and get close to actually driving an EV like car without doing too much modification to it. Because you can tailor the output voltage you can also match it to any Hybrid vehicle such as earlier models you refer to.

Hope that helps.
Hemon

 

[Nick Smith]

There was a guy at the EVCCON convention this year who was big into his prius conversions. I think he was looking into how to go pure electric but unless you want to become a prius hacker I think the best thing is to limit the prius mods to increasing the pack size and to make it a plugin hybrid. The intregration of the drivetrain and electronics turn the seemingly simple idea of a 100% electric prius into a nightmare.

If you want to go down that path though, it would be very interesting to see if the ICE parts could be thrown out to become a pure electric car.

 

[steven4601]

IIRC european version of the Prius has an EV mode. The EV mode keeps the ICE off until the battery is almost empty.

Also there is a BMS available (US based) now which can be used to replace the tiny NiMh pack with a beefier pack of your own choice. The bms provides a way to create a virtual (prius) battery to keep the vehicle CAN Bus electronics happy, and it allows to use the vehicle as an EV or PHEV.

 

[Nick Smith]

I found the guy you are looking for - Steve Woodruff!

web address is "www (dot) autobeyours (dot) com"

 

[albo2]

Hi Alliance do a kit

http://www.alliancerenewableenergy.com/Prius-PHEV-Conversions_c8.htm

 

[clarelb]

There is a company in SoCal/Poway, CA that does plug-in conversions on Prius' >=2004 for $13.5K:
http://www.pluginconversions.com/how.html
http://www.pluginconversions.com/faq.html
Their battery pack gets you 25-30 miles of EV driving and then you revert back to using the normal Prius hybrid engine. That way you can get close to 100 mpg -- or 25-30 miles for 1 electric charge. They also say you can go up to 70mph on the highway with this conversion...

 

[lowcrawler]

Heck with the sales of the new Chevy Volt's, all two of them, I bet if you are patient you can buy a new one for less than $10,000 when Chevy decides to dump it.

I dunno, nearly 10,000 sold ($400,000,000 worth) in the first year is nearly double the number of Priuses sold in their first year (less than 6k) ...

 

[coulombKid]

I dunno, nearly 10,000 sold ($400,000,000 worth) in the first year is nearly double the number of Priuses sold in their first year (less than 6k) ...

It would involve, as other members have pointed out, a lot of interface hacking but I'd like to can the ICE on an Honda Insight and strap a DC motor to the passenger side of the 10Kw AC motor to get a pure EV with enough motive power and still retain the re-gen feature of the AC motor that came in it. Programming one of my Parallax Propellers to mimic the ICE run signals can be done but each out-put would have to be amplified/attenuated to the levels put out by the ICE sensors and frequency scaled to the RPM and load with a look-up table.