2004 Toyota Prius Black

this page was last updated 11-07

please follow this link for the latest phev developments

The "imwoody36 special"

...our first Plug in Hybrid Electric Vehicle or PHEV

Located at 287 N Gardner Scottsburg IN 47170

(30 miles north of Louisville Ky and about 75miles south of Indianapolis In.)

2 or 3 minutes from I- 65


click here for the newest phev information

information 11-28-07


My name is Steve Woodruff and this is the 28th Prius I have purchased. I rebuild wrecked Prius cars exclusively.

This page documents my efforts to add a second stock Prius High voltage battery pack to the car.


I have used Canview version3 to interface with the Prius.


sorry for the poor quality of this schematic... I have posted a visio schematic here ( new information june 07... an easy to use bare circuit board is under construction.. see the eaa-phev.org website)

Results and tribulations:

Aug 30 2006 installed Aux Battery and ECM " Y" cable assy DTC error with regard to battery fan Current sinking the fctl1 brown battery fan relay coil through diodes did not work. switching dpdt resolved the error.
Aug 31 spdt relays used to switch between main relay coils Ready light remained " ON" when aux battery switched into circuit in place of stock battery DTC error " battery ecm lost communications with hv ecu" I plan to keep the unused ecm off until it is placed in circuit.
Sept 1 switched IGCT blue 12v wire between active ecm's ( I am activating the ecm switch manually, while observing the canview Current readout to ensure that I switch at or near a zero amp crossover point) DTC error, perhaps now I will try switching all ecm power on and off, or, conversly perhaps spoofing the unused ecm into believing it is in circuit.
Have had phone calls and emails from many PHEV enthusiasts, Thank you for your input and constructive critisism. I might try leaving both C.A.N. bus circuits online I also might install an obd2 connector on the aux battery ecm for connection to my Toyota Scan Tool. this will tell me when it is sending undesirable information to the can bus.
Sept 13 06, many of you have asked what the progress is this week... I worked on other collision damaged cars to pay the bills while awaiting for this generic relay board kit to arrive.

I have been logging MPG with the new battery in the back but not connected.

also Doug Pope and I are working on remotely accessing Data Trouble Codes on your car over the internet with my scan tool.

sept 18, paralleled can bus wires for the two battery computers only switching IGC2 ( blue wire) removes or enables the correct battery ecu seems to have resolved the communication code set problem, interestingly...having both battey ecus "in" circuit reports fluctuating SOC levels but no trouble codes.
sept 20 drove home and back with aux battery connected stuck closed contactor ( code p0aa1/ 233 ) DTC CODE

I caused one or more relays to fail by accidentally switching them on and off two or three times in less than a second. while testing.

I found replacements and tech notes on the relays here

Oct fault codes again corrected by replacing a faulty wire connector in the CAN circuit.
Nov 10 2006 have been working on gathering mpg data mixed driving seems to be improved.
Feb 2007

Sold the car, and moving the phev conversion to another Prius

( red this time)

I was made a generous offer for the Black prius,
March Installing the conversion into a katrina flooded car, ( new everything Awaiting new improved Circuit board from the Eaa-phev folks to be printed
June 07 work resumed, new target vehicle is another Black 2005 Prius  
June 07 Chris Ewert has suggested an economical overnight charger  
Oct 07 State of charge Spoofing is the newest development allowing the Prius to get super MPG even at Highway speed  
Nov 07 construction of a 160 cell li-ion battery management charger/ cell management with imbedded spoofing interface continues. NEW information 11-28-07




Proposed final mounting for the aux battery.. notice how easy it will be to vent into the stock plenum.


These are the "Before" photos...





This one is number rebuilder 28

Send your questions here

links of interest comments  
this page under construction 11-28-07   http://www.plugincenter.com/
http://www.calcars.org/bettah/index.html a cute animation promoting plug in hybrids  
PiPrius newest plug in prius info  
anti plagerism notice. I fully acknowledge the efforts of everyone in the prius community, see these links!   8051 compiler stuff
EAA-PHEV   prius hacking
atilla   Hybrids Plus very nice Q and A page
hybrid interfaces makers of canview    

visit this car at calcars.org or click here


> A gallon of gasoline weighs less than 20 pounds. How can it produce 20 lbs. of C02?

Good question. Gasoline is not a simple chemical but a reasonable approximation is said to be* C8 H18. When burned completely a mole of

this reacts with 12.5 moles of O2 to make 8 moles of CO2 and 9 moles of H2O. This is all a fun review of freshman chemistry and if I got the

numbers right, the gallon of gasoline, at 6.17 lbs is 22.2% of the weight of the reaction products -- 27.79 lbs. Of this total, CO2 is > 68.5% or just over 19 lbs.

So 77.8% of the dreaded CO2 is supplied by our wonderful atmosphere.

This is the dirty secret behind the magic of hydrocarbon fuel -- you only have to haul a little bit of what makes all that energy!

(this data courtesy of Mike Sasnett)