View source for EAA-PHEV

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This is an Initial Page for the '''EAA-PHEV''' Projects.
Which will focus on the Prius Plus Conversions for the moment.
There are other PHEV projects on the [[Conversion Hybrids]] page and [[PHEV Projects]] page.
CalCars has a great [http://www.calcars.org/calcars-phevtalkingpoints.pdf PHEV talking points] to bring you up to speed regarding Plug-in Hybrids.<br>
"If we knew what it was we were doing, it would not be called research, would it?"  -- Albert Einstein

==Maillist==
'''The maillist discussions contain essential data not covered on this page or in the documentation linked from this page.  They are a must-see for anyone contemplating doing a conversion!''' Endorsed my Mike G. - GO Gators!

See the [[EAA-PHEV_Maillist:]] for past messages and instructions for joining the list.
Another perhaps more familure way to read the discussion is at the archives: http://groups.yahoo.com/group/eaa-phev .
Those who join the group are reminded to observe standard email etiquette and be respectful of each other.  Once you've joined you can send messages to '''eaa-phev@seattleeva.org'''.  The information is provided as a public service and the EAA assumes no liability for its use.   Anyone modifying a Prius or other vehicle does so at their own risk and may void their manufacturer's warranty. 

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==Disclaimer==
<font color=red>
*'''Use this information at your own risk''', there is '''no warranty''' expressed nor implied.  Even should you perform these modifications to the letter you could still cause damage to any number of components in your Prius and cause it to no longer function.  In performing some of these modifications you may also '''void your warrenty with Toyota'''.
*'''HV warning:''' The Prius Traction Battery is a HV (High Voltage) Battery and could cause '''serious injury or death''' if proper precautions are not taken while working with it.
''See also: http://www.airlabcorp.com/Prius/priusdisman.pdf [[:Image:Priusdisman.pdf|Local]] - for dismantle and safety warnings''
</font>

==Terms==
*'''EAA''' = '''E'''lectric '''A'''uto '''A'''ssociation. - http://www.eaaev.org/
*'''PHEV''' = '''P'''lug-in '''H'''ybrid '''E'''lectric '''V'''ehicle.
*'''MFD''' = '''M'''ulti-'''F'''unction '''D'''isplay, or the Touch Screen which is standard on all Prii.
*'''CAN''' = '''C'''ontroller '''A'''rea '''N'''etwork used within the Prius which all the computer systems use to communicate.
*'''SOC''' = '''S'''tate '''O'''f '''C'''harge, similar to a gas guage, indicates how Full or Empty a battery is.

==EV-Mode==
=== Enabling EV-Mode Button ===
* Enabling the [[User:Rjf/Prius_Modifications#Enabling_EV-mode_Button_.22H14_.2327_to_ground.22|EV-Mode Button]]
EV-only mode is auto canceled outside of the following limits:
* >=180V
* >=45% SOC (mode cannot be entered unles SOC is >=50%)
* Accelerator pedal position <=120 (out of 255), corresponds to approx. 120A or 24kW
* Vehicle speed <34 mph (55 kph)
* Defrost not selected (and possibly some other control selections)
Notes:
* The ICE will start 7 seconds after vehicle startup unless EV-only mode is entered during that time.
* Once the ICE starts the first time during a trip, it will not stop until it has warmed up.
* The A/C compressor is electric, and the A/C will work while in EV-only mode.
* When the EV-only mode is entered, the hybrid model screen will show.  A beep will be heard only if that screen wasn't already showing.
* Three beeps are heard whenever EV-only mode is requested but not allowed, and when it is auto canceled.<br>One must wait around five seconds before a new EV-only request is acknowledged.
Regenerative braking is limited by all of the following:
* 120A
* ~30A if SOC is >=80%
* HV 250-270V (progressively greater limitation)
None of the above voltage limits have been tested for temperature-based variations.

===SOC Spoofing===
The Prius' battery management computer (BMS, called the Battery ECU) communicates to the main hybrid computers via the CAN bus.  It indicates battery voltage, current, temperature, and its estimates of state-of-charge (SOC), and maximum allowable charge and discharge current.

The BMS' estimate of SOC is critical, as the hybrid controller keeps SOC within 40-80% (the lower and upper limits of the (nonlinear) display graph), and tries to keep it around 60%.  When the SOC is above 60%, the hybrid controller works to discharge the battery by using battery power (and less gasoline) even during normal cruise.  This increases to around 30A (~6kW) at 70% and above.

When the SOC is below 60%, the hybrid controller works to charge the battery by making the ICE work extra hard even during normal cruise.  Below 40% SOC, stranger things happen and it is difficult to get the engine to put out much power at all.

For a PHEV, the object of SOC spoofing is to keep the BMS's indicated SOC at 80% or above until the battery is discharged enough to accept significant regenerative braking current; then between 70-80% -- to force less gasoline use even during non-EV-only mode -- until the battery's real state-of-charge has come near its lower limit.  At that point, the BMS's indicated SOC should hover around 60% to keep the battery's real state-of-charge from trending further downward (bad for the battery) or upward (thereby wasting gasoline).

Dan Kroushl did some experiments with higher voltage batteries that proved that the BMS's indicated SOC can be spoofed (Thanks, Dan!).  That led me to do enough further experimentation to discover that it is definitely possible to do what I indicated in the above paragraph, and generally how to do it.  However, the circuitry and programming to do so is still in development. It generally involves, as needed, providing a higher voltage to the BMS than the actual battery voltage.

Toyota's BMS also checks the voltage of 13 taps on the OEM battery.  These voltages must be equal to each other or the BMS will indicate a fault.  Since few PHEV battery packs, unlike the OEM pack, are divisible into 14 equal subpacks, these tap voltages must be spoofed, too.  Fortunately, it has been found that a fairly simple voltage divider can accomplish this.

Because of all of the above, CalCars' overall PRIUS+ circuit diagram is still in flux, and definitive answers about it are as yet unavailable.

===SOC management===
Here is the minimum needed in terms of a computer for spoofing the Prius' built-in BMS:
* CAN message reading and parsing (CAN bus writing is NOT necessary or even desirable)
* '''The ability to separately close and open two reed switch contacts based on CAN information'''
** one to set EV-only mode, based on it not already being set, speed <34 mph, power request <120 (out of 200), SOC >49%, and a few other parameters.
** one to set a voltage boost (to be explained later) to keep perceived SOC within a given range until the battery is sufficiently depleted
* Amp-hour integration and display from the appropriate CAN bus messages
* HV battery voltage and current display (both analog and digital desirable) from the appropriate CAN bus messages
* Display of trip info (since reset):  # of CAN errors (important for debugging), odometer, milligallons of gasoline used, Amp-hr and/or kWh used, trip milligallon/mi, Wh/mi, and mpg, highest peak charge and discharge currents, highest and lowest HV battery voltages, and the battery's internal resistance (beginning, current, and end)

Additional displays, desirable but not necessary:
* Not strictly necessary, but SUPER desirable:  storage of CAN trip running data on a removable medium (like a CompactFlash card) for later analysis.
* Small graphical engine tachometer (but see rectangular suggestion below)
* Gasoline use rate (milligallon/min and/or milligallon/mi (inverse of mpg), or just a binary for gasoline being used
* Tiny graphical brake cylinder pressure (sum of that for each wheel), to indicate amount of non-regenerative braking being used

A very cool display would be two rectangular graphs indicating engine and electric power:
* Engine power (e.g. blue for combustion):  vertical: RPM, horizontal: torque
* Electric (e.g. red for discharge, green for charge):  vertical: HV battery voltage; horizontal:  HV battery current (absolute value)
The areas can be calibrated so that they show the relative power being produced by the electric motor vs. the engine.  The same pair of rectangles could display and compare the power going into regenerative braking vs. that being wasted in the friction brakes.

==Batteries==
* Any battery which meets the minimum requirements could be used to replace the [[Prius Battery Specs|Stock Prius]] [[Ni|NiMH]] battery pack.  The stock battery does not necessarily need to be removed, but should probably be disconnected while in PHEV mode.
* '''CalCars''' has used 18 EVP20-12B B&B 20Ah 12v SLA [[PbA]] batteries from [http://www.electricrider.com/batteries.htm ElectricRider.com] (12Ah at 2C rate) for a total of <!--14.4vpc?-->3.1 kWh.  These cost $700, deliver 10 miles per cycle, and are expected to last 200 cycles for $0.35/mile.
* '''EDrive''' plans on using 18 ''exotic'' 12V U-1 U-charge 40Ah @C/5 Li-ion batteries from [[Li#Valence|Valence]] for a total of 9.9 kWh.
* Another PbA possibility is the Exide Orbital ES26-12X.  It is 25% heavier but may have longer cycle life than the B&B EVP20-12B.
** Jul 21, 2005 [http://groups.yahoo.com/group/priusplus/message/468 Battery evaluation and production cost summary] by: Ron Gremban
* You may want to use some [http://www.andersonpower.com/ Anderson] high power connectors for DC.

===Minimum Requirements===
We will focus on the Voltage requirements, as the AmpHour capacity of the pack may vary depending on who's implementing it and for what type of useage for various ranges from 5 to 50 or more miles.  While a PbA pack may only deliver about 1/2 its nameplate capacity (due to Peukert's Law, which does not affect other chemistries) a Lithium pack may be able to deliver all of it's nameplate capacity.  It all depends on how the battery's capacity is rated.  The Prius consumes about 1 Ah or 300 Wh per mile.

* The 6.5Ah '''Stock NiMH pack''' consists of 168 cells (28 modules) in series.
** 60% nominal to 45% minimum SOC => 15% of 6.5 Ah is 1 Ah for 1 mile EV-only range.
** 80% maximum to 45% minimum SOC => 35% of 6.5 Ah is 2.2 Ah for > 2 miles EV-only range.
** Nominal Voltage is 201.6v, ranging from 180v to 270v durring use.
* The 20Ah '''CalCars PbA pack''' (12Ah at 2C rate)
** Delivers ~10 miles EV-only or 20 miles mixed-driving PHEV range.
** Nominal Voltage is <!--12.0vpc-->216V, ranging form ???v to ???v durring use.
* The 40Ah '''EDrive Li-ion pack'''
** Delivers ~30 miles EV-only or 60 miles mixed-driving PHEV range.
** Nominal Voltage is <!--12.8vpc-->230v, ranging form ???v to ???v durring use.

CalCars' published chemistry-neutral PRIUS+ battery spec is reproduced below.  We have found 18 12V PbA modules or 180 NiMH cells in series to be near optimum.

Note: our PRIUS+ gets approx. 1 mile of pure EV range (or 2 miles of mixed driving range, with double normal gasoline mileage) per Amp-hr expended from the battery.  Therefore, a 30Ah battery, used to 70% depth-of-discharge (DOD) would provide 24 miles of EV-only range or 48 miles of mixed driving PHEV range.

* California Cars Initiative PRIUS+ Project - Preliminary Public Chemistry-neutral Battery Pack Specification
* Subject to Change 6/17/05 By Ron Gremban
** Voltages:
*** Maximum (during regenerative braking, 120A or max for SOC):  260V
*** Minimum (during 120A discharge at minimum normal SOC):  180V
*** Nominal:  210-230V (depends on the chemistry)
** Amp-hr at 60A rate: 30-50 (5.5-10.0 kWh)
** Max intermittent discharge rate: 200A
** Max intermittent charge rate (when SOC is low enough to accept this full rate): 120A
** DC internal resistance*, over normal range of SOC: Less than 0.25 ohm (0.20 ohm desired)
** Charge equalization: Please indicate requirements and provisions for charge equalization
** Thermal management: Please indicate requirements and provisions for thermal management
** Min cycle life*: At least 1000 cycles between normal SOC limits; 2000 cycles or more highly desired
** Max battery pack weight*: 300 lb (136 kg); 170 lb (77 kg) desired (replaces 70 lb hybrid battery)
** Max price*: $800/kWh or less to CalCars, including charge balancing, cooling, thermal management, and SOC monitoring
** Projected high-volume auto manufacturer's cost in two years*: $0.40 or less per kilowatt-hr lifetime throughput
* *The values of these parameters should be maximized (or minimized, as appropriate), given a reasonable cost of doing so

===Battery analysis by Richard===
per this [[EAA-PHEV_Maillist:2005./12./2|maillist message]]:<br>
I have completed my analysis for the battery pack and am attaching it. The first attachment explains the analysis and the second is a spread sheet of some of the data I ran.
* [[:Image:Minimum_cost2.doc]]
* [[:Image:Bmax.xls]]

==Chargers==
[[Image:Prius Charger.jpg|thumb|100px|right|[http://groups.yahoo.com/group/2004-prius/message/40720 THS Charger]]]
* CalCars uses a Brusa NLG5 charger from MetricMind.com.  This is a $4000, 4kW charger capable of being reprogramed for any chemistry and any voltage output up to 520V.  It is invaluable for our experimentation, especially since, for our world's first PRIUS+, we didn't know what would be necessary.  A less flexible, lower power, less expensive charger may be more suitable for subsequent conversions.
* CalCars believes that most PHEVs need only a 1 kW charger, able to plug into ordinary 120V, 15A GFI circuits.  Since gasoline is available as a range extender, charging need be no faster than overnight.
* [http://groups.yahoo.com/group/ev-list-archive/message/51581 PFC-20 Running off Prius HV Pack] [http://groups.yahoo.com/group/ev-list-archive/message/51660] Charging a BEV. This charger could run in both directions.
** charging from the grid to the additional pack
** charging from the additional pack to other EV's
** charging from the Prius ICE/Gas to other EV's (up to 10kW)

==User Interfaces==
===CAN-View Scanner===
[[Image:Inimech.jpg|thumb|right|One of the graph screens<br>[http://www.seattleeva.org/index.php?title=EAA-PHEV&oldid=1093#Screenshots CAN-View local gallery]
<br>'''See the [http://www.hybridinterfaces.ca Official Website]''']]

This is a MFD Integrated CAN Scanner, named CAN-View.<br>
The Official Website is http://www.hybridinterfaces.ca

* http://priuschat.com/index.php?showtopic=11644 [http://groups.yahoo.com/group/Prius_Miniscanner_MarkIII/message/614 yahoo] [http://priuschat.com/CAN-VIEW-monitor-t12077.html Lost] [http://www.google.com/search?q=cache:9yflkBICdmIJ:priuschat.com/index.php%3Fshowtopic%3D12077 C1] [http://www.google.com/search?q=cache:OQWcUZ8AF-kJ:priuschat.com/page-2-t12077-s20.html C2] [ C3] 
* http://priuschat.com/index.php?showtopic=2281 hardware level display hijacking, unrelated?
* Now available at http://www.priuschat.com/shop/
** Help installing it : [https://www.metrotpn.com/documents/PDF%20Files/Prius/Eddie's%20XMRadio%20Install/PriusXMradio3.2.pdf] [http://www.chrisdragon.com/downloads/Stereo%20Accessory%20Install%20Guide,%2004%20Prius,%20v1.03.pdf]

'''Additional accessories'''<br>
These additional features are supported by the 2nd version of the CAN-View, some require additional hardware.
*Aftermarket Navigation System Interface ''([http://www.google.com/search?q=Pioneer+AVIC-88 Pioneer's AVIC-88])''
*Serial MFD touch screen coordinates are outputted from the CAN-View via a serial DB9 RS232 port.
*SCART Plugs and cables. [http://cpc.farnell.com/jsp/endecaSearch/searchPage2.jsp?Ntt=scart+sockets&Nty=1&N=411&Ntk=gensearch]
*A $110 CC2RGB converter from http://www.threedoubleyou.com/otherconverters.htm outputs composite NTSC video via the CAN-View.
* Field Programming - http://priuschat.com/index.php?showtopic=11644&st=40#
** The Silabs development kit C8051F310DK (available on the DigiKey website at US$99)
*A $99 BOBIII device from http://www.decadenet.com outputs clean RGBs to the MFD via the CAN-View, it uses serial input to create color text.

===My CAN Project===
[[Image:Www.vassfamily.net-Others.jpg|thumb|right|[http://www.vassfamily.net/ToyotaPrius/CAN/cindex.html Vass] Software on the left]]
OK, not ''"My"'' Can Project, but some very nice software none the less.
*http://www.vassfamily.net/ToyotaPrius/CAN/cindex.html
: May Required Linux ''and all that that entails''
: '''Open Source''' courtesy of Attila Vass!

===Other CAN scanners===
*http://www.ecrostech.com/Products/MiniScanner/Intro.htm [http://home.earthlink.net/~graham1/Prius/MiniScanner/MiniScanner.htm]- Classic Prius (2000-2003)
*http://groups.yahoo.com/group/Prius_Miniscanner_MarkIII - THS Prius (2004+)
*http://www.hemdata.com/Products/Dawn - Another CAN scanner, with HEV screenshots.
* [http://babelfish.altavista.com/babelfish/trurl_pagecontent?lp=ja_en&trurl=http%3a%2f%2fpriusdiy.fc2web.com%2findex.html priusdiy.fc2web.com/index] - Translated from Japanese to English
*http://www.ecrostech.com/prius/original/PriusFrames.htm
*http://www.carplugs.com - Source for OBD2 connectors.

==Schematics and Documentation==

* Here is the complete PRIUS+ documentation package as of 1/26/2006.
* [[EAA-PHEV PRIUS Documentation]] ([[Media:EAA-PHEV-PRIUS-.doc|.doc]])
** - [[:Image:EAA-PHEV-PRIUS-ControlSchematicV1 060118.png|SOC & Control Schematic]] - - [[:Image:EAA-PHEV-PRIUS-BatteryTapEmulatorSchematicV1a 060118.png|Battery Tap Emulator Schematic]] - - [[:Image:EAA-PHEV-PRIUS-HighPowerSchematicV1a 060116.png|High Power Schematic]] - 

{{EAA-PHEV-Prius-Schematics}}

==Management Pseudo Code==
This is the management pseudo code which determines how the Prius PHEV functions...

===CAN Parameters===
Thess are CAN Parameters of particular interest used in the pseudo code:
* '''SOC''' - The reported SOC is used to determine when to enable the SOC Spoofing circuit which raises the perceived or reported SOC.
* '''Speed''' - Used to determine when to re-enter EV-mode after leaving it due to high speed or power demand.
* '''Voltage''' - The reported Voltage is that measured by the Prius which may or may not be the '''Real Voltage'''.
* '''Amperage''' - The reported Amperage is the amount of current being removed from or added to the battery.
* '''Temperature''' - Battery temp used for temperature conpensation.
* '''Spoof Voltage''' - Determined by measuring the difference in reported '''Voltage''' which occurs when the SOC Spoofing circuit is enabled.
* '''Real Voltage''' - Used to determine the replacement HV batteries real SOC.
** Real Voltage is reported '''Voltage''' if the SOC Spoof circuit is disabled.
** Real Voltage is ''Spoof Voltage'' subtracted from reported '''Voltage''' if SOC Spoof circuit is enabled.
* '''Real SOC''' - Could be determined in a number of ways using '''Real Voltage''' and reported '''Amperage'''. <br> '' ''' This aspect had not been fully resolved, so more details are sure to come at a later time''' ''
** Zero Crossing SOC - Used to determine the real SOC by measuring '''Real Voltage''' as '''Amperage''' crosses zero.
** Under Load SOC - Used by combining '''Real Voltage''' and reported '''Amperage''' in a manner to determine the batteries internal resistance, which is an indication the batteries SOC.
** Watt Hour SOC - By counting Watt Hours removed from and added to the battery one can determine how much energy is left in a battery given that you knew how much you had to begin with, the capacity of the battery, and it's puckert characteristics.  Unfortunantly WH counting is unlikely to be accurate based on the amperage, voltage, and power levels reported on the CAN buss as these are pre-filtered.  Additional hardware such as a dedicated WH meter would be nesicarily to implement this type of SOC indication, however it may not be a bad idea use such a device even if not integrated as a control device.
*** See [http://autos.groups.yahoo.com/group/ev-list-archive/message/42128], [http://autos.groups.yahoo.com/group/ev-list-archive/message/42428], [[EVDL_Maillist:2003./8./333]], and [[WikiPedia:Battery pack]] for more SOC calculation discussions.

===User Settings===
* Note: Below within the code logic ''_XX_'' are user settings, the listed value is a best guess default for that setting.  These may need to be changed in order to allow for various battery chemestries and user preferances.
** ''_30_''seconds - Denied Timeout
** ''_82_''% - Spoof circuit enable SOC level
** ''_20_''% - Real SOC lower limit
** ''_40_''% - Real SOC PHEV entry lower limit
** ''_33_''MPH - EV-Mode re-entry speed

===Pseudo Code Logic===
* Initialization and Discovery:
** Upon startup the current state of the system is unknow, has the battery been left discharged or is it fully charged?
*** Determine current '''Real SOC''', using '''Temperature''' compensated no-load or zero-crossing '''Real Voltage'''.
** Depending on the user settings and the CAN management device PHEV mode might be entered immediatly given that '''Real SOC''' is high enough.  ''Temperature might also be considered if it is very low, sub-freezing?''. ''Defroster settings might also disable PHEV-Mode from the Prius side of the system''.
*** Enter EV-Mode, Verify EV-Mode was entered
**** If EV-Mode denied, timeout re-attempts for ''_30_'' seconds
** If '''SOC''' < ''_82_''%
*** Then enable SOC Spoof circuit
**** Measure voltage differance to aquire '''Spoof Voltage'''.  ''Cycling of the SOC Spoofing circuit for multiple samples may provide more accurate readings''. ''This setting might be saved by the CAN management device as it should rarely change and is manually set''.
*** Else disable SOC Spoof circuit
**** still enable momentarily to determine '''Spoof Voltage'''.

* PHEV-Mode Loop Start
** If '''SOC''' < ''_82_''%
*** Then enable SOC Spoof circuit
*** Else disable SOC Spoof circuit
** If '''Speed''' < ''_33_'' MPH and EV-Mode is not enabled
*** Re-enable EV-mode
**** If EV-mode denied, timeout re-attempts for ''_30_'' seconds
** If '''Real SOC''' < ''_30_''%
*** Then leave PHEV mode and return to normal HEV mode, End PHEV-Mode Loop, Enter HEV-Mode Loop.
** Return to PHEV-Mode Loop Start

* HEV-Mode Loop Start
** If '''Real SOC''' > ''_40_''%
*** Then re-enter PHEV-Mode Loop
* Return to HEV-Mode Loop Start

==Installation Photos==
Thought we might put a collection of photos that relate to the physical installation to help visualize just what is involved.

===Ron G===
* Ron G is trying to get many detailed pictures of his/CalCars PRIUS+ with its B&B PbA batteries uploaded for additional reference.

===From Yahoo===
<gallery>
Image:04 HV & PbAcidParallelTie2.jpg|HV tie-in
Image:04 Prius HV Battery Fuse.jpg|HV Battery Fuse<br>''Is this also the disconnect?''
Image:04 Prius accessory battery disconnect.JPG|12v accessory disconnect
Image:Prius_Outlet.jpg|Humorous Prius Outlet
</gallery>

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[[Category:EAA-PHEV]]