Plugin Conversion Kit For Gen2 Prius

[haydoor]

Hi All,

I was wondering if anyone in the UK has had their Gen2 Prius converted to a plugin version. I noticed a number of kits available in the US and one from a company called Enginer seems reasonable in costs.

Thx

Haydoor

[Grumpy Cabbie]

You'll want to speak to Mr Flaninacupboard (don't ask bout his name! lol).

He has converted his gen3 with an enginer kit, but I think it's the same, or at least a very similar kit for the gen2.

I considered the conversion BUT it is not for those without even basic electrical engineer experience. Also, by the time you've imported it, paid import duties, VAT, shipping etc the price goes up somewhat. Mr Flan is a friendly chap and I'm sure he'll give you all his experiences with his Enginer kit. I do recall he has an extensive thread about this on the Priuschat forum.

[Flaninacupboard]

Cheers Grumpy, always nice to be described as friendly!

haydoor,

I have the Enginer kit in my gen3. It's a lot of fun, and a cool thing to talk about, but it's not going to save me money any time soon (payback period is over 2 years). i averaged 64mpg before the kit, and 89mpg after, which sounds great, but given the prius is using so little fuel to begin with the actual £ saving is small. I don't mind, sending a bit less money to saudi arabia is good, driving on electricity powered from the wind (Ecotricity) is also cool. It just makes me REALLY want an EV

The kit for gen2 and gen3 is basically the same, just laid out internally back to front (because of the location of the service plug). I did have some problems, mainly caused by bad calibration in the BMS. that was a version 3.0 BMS and the current kits ship with version 4.0, mine now with version 3.3 is working perfectly.

If i were starting over, and didn't already have a prius, i would go for a gen2 with a plugin-supply kit. it is more expensive, but you get a real EV mode. at the moment only the Enginer kit works with gen3, but more should appear someday, i am hoping for one to replace my current system some time late next year. It would also be nice a company to start up in the UK doing the conversions, as right now it's DIY and there is lots to do.... :)

[Jolly English Gentleman]

It would also be nice a company to start up in the UK doing the conversions, as right now it's DIY and there is lots to do.... :)

I think somebody might have tried http://www.pluginplanet.co.uk/ but perhaps not got that far because of price and the consideration that it is relatetively untested over here. Does a Plugin conversion kit class as a modification for insurance purposes?

The big question I have about plug in's is how do you compare the cost of an electric charge with the cost of petrol? Are there any tables that allow you to covert a plug in charge costing x pence to mpg which would enable one to work out payback costs based on current petrol prices?

[Grumpy Cabbie]

Does a Plugin conversion kit class as a modification for insurance purposes?

Has it been modified in any way from manufacturers specifications? Erm, if you answer No to that then there's no hope. Of course it's a modification and many insurers will run a mile. That's not to say others won't mind so long as you tell them what you've done. Always best to tell them.

[Flaninacupboard]

I think somebody might have tried http://www.pluginplanet.co.uk/ but perhaps not got that far because of price and the consideration that it is relatetively untested over here.

Well the products on their website are over a year old, so i assume they're not very active.

Now that the offical toyota plugin is about to go on sale there should be a lot more interest in the conversions. Paying £5k to upgrade your existing car is a lot more attractive than (probably) £30k for a new one with a plug. If i had any experience in operating a small company i'd love to give it a go, as i have the technical knowledge required.

Does a Plugin conversion kit class as a modification for insurance purposes?

Yep, i paid a £17 admin fee to have it added to my insurance info, and at renewal, nothing. It's not really any different to the guys who add extra batteries for large audio setups, and they probably don't inform their insurer about that.

The big question I have about plug in's is how do you compare the cost of an electric charge with the cost of petrol? Are there any tables that allow you to covert a plug in charge costing x pence to mpg which would enable one to work out payback costs based on current petrol prices?

I don't have a table i can publish, but here's some maths.

A gallon of petrol contains 42kwh of energy.

The Prius can convert that with ~30% efficiency, so we get 12.6kwh of usable energy per gallon.

At £1.30 a litre (is that the right price? not bought any for a few weeks?) that is £5.89 a gallon, or £0.47 per kilowatt hour of usable energy.

My kit holds just over 4kwh, and you can use just about spot on 4kwh. it takes about 5kwh to charge it fully. the 4kwh in the batteries goes through a DC converter, which is ~90% efficient, and into the prius DC bus. We have to assume here that ~90% gets to the drive shaft (that's boost converter, inverter, and MG2 losses within the existing drivetrain.)

That is 4kwh * .9 *.9 or 3.24kwh of usable energy being delivered. That is directly displacing (3.24 / 12.6) 0.26 gallons of petrol, 1.16 litres, £1.51 of petrol. If your electrcity tariff is less than 30p per kilowatthour (£1.51 divided by the 5kwh needed for a full charge) then PHEV is cheaper than petrol. Typical prices seem to be about 10-15p per kilowatthour, so any plugin miles are half the cost of petrol miles.

The prius is a victim of it's own success here. In another vehicle, such as a Ford Escape hybrid, which can probably only convert petrol to usable energy at around 20%, the maths a different, with plugin miles costing about one third what petrol miles do (and those petrol miles are significantly more expensive, so the £ saving is much greater).

I guess for me, with pre conversion MPG of 64, my cost-based MPG on plugin mode is 112. While not in plugin mode i still get 64, so my combined/real world MPG is 89.

There's a fair amount of loss in this system (still less than petrol, and my electricity is 100% renewable so i am not too concerned) and something i'd like to do is actually take a gen2, remove the engine altogether and replace with a DC motor. retaining the rest of the hybrid hardware gives you a 35hp power boost when needed, and all the existing systems (regen braking, traction control, brake vacuum etc etc) remain in place. You could use a ~20kwh pack (4kwh under the bonnet, 4kwh in the tyre well, 4kwh behind the traction Battery, and 6kwh behind that - last 2kwh not sure where to put) and get something close to a 100 mile range. The cells from GWL would be about £5,300 and another £1,500 or so for the controller, BMS and charger, then about £1,500 for the motor.

Hmm, bit of a diversion.... sorry!

[Grumpy Cabbie]

... something i'd like to do is actually take a gen2, remove the engine altogether and replace with a DC motor. retaining the rest of the hybrid hardware gives you a 35hp power boost when needed, and all the existing systems (regen braking, traction control, brake vacuum etc etc) remain in place. You could use a ~20kwh pack (4kwh under the bonnet, 4kwh in the tyre well, 4kwh behind the traction battery, and 6kwh behind that - last 2kwh not sure where to put) and get something close to a 100 mile range. The cells from GWL would be about £5,300 and another £1,500 or so for the controller, BMS and charger, then about £1,500 for the motor.

This I'd like to see. Does it have to be a gen2? You can get some knackered grey import Prii for under a grand. You'll be replacing the HV Battery so it doesn't matter that the one in the car is shot.

[Flaninacupboard]

Yes, gen2 has an engine ECU which is completely seperate on the CANBUS. You can filter the messages (so don't allow the messages saying "I CAN'T FIND THE ENGINE!!" to get to the hybrid ECU, while intercepting the message from the hybrid ECU requesting a specific engine speed and passing that onto the motor controller), which is similar to what pEEf has done on pchat. Gen1 has some accesory belts (definitely for A/C and maybe also engine coolant, can't remember) which make it less desirable. My idea also relies on the original traction Battery remaining in place. a 20kwh lithium pack can only really provide 20kw of power. Teaming up with the 1.2kwh Nimh pack which can provide 21kw on it's own allows you to retain decent peak output, and it can accept 100amps of regen current which your lithium pack probably couldn't...

The more i find out about batteries the more impressed i am with the Nimh pack in the prius.

[Grumpy Cabbie]

The more i find out about batteries the more impressed i am with the Nimh pack in the prius.

Which is why Texaco bought the patent and wouldn't allow anyone to use Nimh for electric cars?

[Flaninacupboard]

The more i find out about batteries the more impressed i am with the Nimh pack in the prius.

Which is why Texaco bought the patent and wouldn't allow anyone to use Nimh for electric cars?

Pretty much :(

The Nimh EV1 produced 102kw from a 26kwh pack, that's 3.9C. Todays Leaf gets 90kw from a 24kwh pack, that's 3.75C. With continued development i'm sure Nimh would have improved upon it's energy density, in the same way we have had to really improve the power density of lithium to get to Leaf levels, and that has taken the best part of 15 years....

[sjrainsford]

Just gotta say, i'm a +2 on Ecotricity!

[semo]

Is there a way to register a converted gen 2 in order to be exempt from the CC under the new rules? I think that only expensive new EV/PHVs will qualify for all the tax incentives :(

[Flaninacupboard]

You can register the fuel type as PHEV with the DVLA with some proof of the work. if they decide to exempt all PHEVs (regardless of emissions levels) then you are set. If you wish to change the emissions level then the revised number would have to come from Toyota. I've requested a re-test of my car (twice) and had a response to the effect of head office have to deal with the request, and then nothing more.

[semo]

You can register the fuel type as PHEV with the DVLA with some proof of the work. if they decide to exempt all PHEVs (regardless of emissions levels) then you are set. If you wish to change the emissions level then the revised number would have to come from Toyota. I've requested a re-test of my car (twice) and had a response to the effect of head office have to deal with the request, and then nothing more.

I think you will find this a losing battle. I also doubt that the government will recognise either yours or Toyota's emission results. I can't imagine how much red tape is needed to alter a vehicle's economy label, but if you pull it off, do tell!

It would have been so much cheaper to just get an old gen 2 and upgrade it with amberjac's 35 mile kit. The PHV Prius won't even do that many miles in EV mode whenever it comes out.

Edit: Also due to the Euro 5 emission standards, cars will soon have to be emitting less than 80g/km or be full EVs before they are exempt from the CC. The fact that they could be plugged might be entirely overlooked.

Edited October 26, 2011 by semo

[Flaninacupboard]

It would have been so much cheaper to just get an old gen 2 and upgrade it with amberjac's 35 mile kit. The PHV Prius won't even do that many miles in EV mode whenever it comes out.

Yes, if starting over i would get a gen2 and a higher capacity and more powerful plugin kit(or make one, with the orion BMS). Not sure about Amberjac, they don't seem to list any products for sale on their website.

Really, i'd like a pure EV, but i also only want one car. Until there's a proper national fast charge network that kind of discounts the current EV's.

[semo]

Actually, amberjac no longer offer conversions. I just had an email conversation with them and even if you did get one of their kits, you wouldn't be able to benefit from any government incentives.

Apparently they still have some used kits available if you ask really nicely.

[Sush]

I am now distributing PHEV kits in the EU. plughybrid.de. Will be registered in a couple of days here in the UK too. I am currently on tour in the uK building an Installation and Service network. If you would like to see the kit in action contact me. I am a Test Engineer by vocation but got in to this just to bring it to the EU. I had to get it certified and define the specs for the EU market.

Sush

[wass]

had a look at the website... very informative indeed.It would seem to be quite a useful modification to make to a car which is well known to be able to cover 1/4 miles with very few difficulties.

[Sush]

That reminds me, in the automotive world the term "modification" has many implications for vehicle certification and insurance.

The MD-Tech kit is E-Marked and is classed as an Electronic Sub Assembly, a Separate Technical Unit. This classification means that the vehicle has not been "modified" and does not need any extra certification. Insurance companies only need to make a note of the installation, it does not affect your insurance premiums or cover, unless you want extra insurance to cover the kit also.

I will add this info to the website.