Where is a easy location to access Traction battery Voltage and Current?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Meter guy, Jan 25, 2013.

  1. Meter guy

    Meter guy Junior Member

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    ive done some research and see the process of removing and installing the traction battery, but thats alot of work for what im interested in doing.....

    im looking for an easy way to tap into the 200v DC line of 07 prius, im interested in putting in a 240V DC meter for monitoring while driving and stationary. i see the high voltage lines under the hood aswell.....

    question 2. is where is there enough space to put a Current Transformer for current flow measurement in and out of Traction battery, preferably without taking cover off battery.

    the battery is still under warranty and i don't want to dig into it.

    im still considering the CAN network monitoring, but i have a history of individual gauages and looking forward to installing some.


    im no stranger to electrical work or meter installations as they are a hobby and a job, just am not YET familiar with my Prius wiring locations. :)
     
    #1 Meter guy, Jan 25, 2013
  2. V8Cobrakid

    V8Cobrakid Green Handyman

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    are you simply trying to track the amps going in either direction and voltage... or are you wanting to figure out the Kwh ratings? (of sorts...)

    I have a scangaugeII and it allows the former, but not the later
     
    #2 V8Cobrakid, Jan 25, 2013
  3. pjc

    pjc Member

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    You don't have to remove the battery for access to its terminals, just its outer cover. You have to remove the back seat to get at some of the bolts. Once you've done it once, it is quite simple. I don't think you will void any warranties with a little digging.... No matter where you tap into the HV lines, you have the same risks to the battery. FYI, battery voltage isn't as interesting as you think.

    There is already a current sensor in there monitoring the current for you. If you want a standalone gauge, then here is some info on how to use the existing sensor. Same page will also show you how to access the battery terminals. I thought about this mod (I like standalone gauges, too) but couldn't find a suitable meter to use.

    If you like standalone gauges, consider adding a tachometer -- immensely useful with a Prius as it shows you when the ICE is running (the arrows on the MFD can be misleading) and how hard you are working it. You don't have to do the meter mods Hobbit went through. I just used a standard cheap (Sunpro) tachometer .
     
    #3 pjc, Jan 25, 2013
  4. Meter guy

    Meter guy Junior Member

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    PJC, i am definitely interested in a tach, where did you take your pulse signal from?

    the hobbit info is quite interesting, i may go that route, using existing sensor.

    its interesting to know the Battery pack is made up of cells that are 7.5 volts and approximately 7 amps each, but yet the pack is fused with a 100+ amp fuse. logically the pack is probabally not accepting more than about 10 amps max to charge, but could possibly sink 20 amps during a hard pull.

    i dont anticipate seeing the voltage fluctuate much, im guessing it may flutter between 185-205 volts. the charge discharge amps will be more interesting.


    V8cobrakid,
    at this time not figuring Kwh, but.....being i work with Killowatthour electric meters, there may be one in the cars future that tracks DC :)

    in my previous car, a 81 phoenix, i had custom installed a 2nd separate electrical system, the 2nd system was a high output 120-140amp alternator, to a trunk battery and a 2000 watt inverter supplying to a home window airconditioner, and i used a KWh meter to track its usage.

    Electric AC system experiment install | Facebook

    the above link goes to the ac project.

    i think its sooooo cool my 07 prius has an electric AC system, theres so many benefits over a traditional mechanical system

    heres my digital gauage install on the 81 phoenix
    Digital guage panel install (December 2009) | Facebook

    i like information :)
     
    #4 Meter guy, Jan 25, 2013
  5. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    I have been in the HV system of my Prius a lot making my own CAN reader. I also work on pure EV's and automotive instrumentation for vehicles (I was at SEMA this year too).

    The pack can sink or source 120A (yes 1-2-0 Amps) at somewhere between 180VDC (lower threshold where it goes into current limiting) and I have seen just under 260VDC when regenerative braking from 90+mph on a downhill incline off ramp for prolonged time.

    It would seem that all the information you seek is already available via the onboard CAN network.
     
    #5 2k1Toaster, Jan 25, 2013
  6. pjc

    pjc Member

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    Yes, it is. The OP wants some analog gauges, presumably, though.

    Meter guy, the Prius already more-or-less tracks "kwh" in/out of the battery. It needs to do so to determine SOC, which is on the CAN bus and is easily read by a scangauge (SOC is also shown with the little battery icon on the MFD). It tracks SOC by Coulomb counting with the Hall sensor you are thinking of tapping.

    Info on the tach signal is also on Hobbit's page (click the word "tachometer" in my post above). Also, here is a link to his main page where he has other interesting Prius mods and info, if you're interested.
     
    #6 pjc, Jan 25, 2013
  7. V8Cobrakid

    V8Cobrakid Green Handyman

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    just a little note.... i use the scangaugeII (mentioned above) to track amps, fuel gauge from the tank, ICE rpms, and average mpg per trip. i used to check out the voltage a lot... not so much anymore unless i have a problem (such as the overfill that caused a p3193 from jiffylube overfilling my oil... long story)

    (i think that was the error code... maybe p3093... either way irrelevent)

    i've seen amps spike up to 150+ accelerating and a tad under 100 regen
     
    #7 V8Cobrakid, Jan 26, 2013
  8. Meter guy

    Meter guy Junior Member

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    thank you all for replying..i have been thinking, i need to see what info is out there on the CAN and then determine what i want to watch with analog gauges.

    i purchased the ELM327 Bluetooth adapter on ebay, i have tested it with a generic OBDII app on my phone and it works.

    i have downloaded the latest Priidash zip file, but am confused about installing, it appears alot of manual config is required before program is actually run, such as setting up of a terminal program and entering in command line info.

    it is mentioned in other threads on priuschat there is a windows version, but i cant seem to find it on their website, or on the net. i found a website that says they have it, but when i click on link i get an website error

    anyone have a link to the location of the windows version?
     
    #8 Meter guy, Feb 1, 2013
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