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Charging PIP with less than 15A?

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by CraigCSJ, Nov 29, 2011.

  1. CraigCSJ

    CraigCSJ Active Member

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    I can see visiting a friend and wanting to charge my PIP but not finding a dedicated 15A outlet handy. It would be nice if we could decide to charge using 120V and maybe only 8A so as to not mess up the friend's electrical system. Of course the charging would take longer, but a slower charge that worked would be better than a faster charge that shut down the system. Somewhere I thought I read that the Volt could charge 120V at 8A.

    Does anybody know if the PIP can reduce the 120V amperage draw, and if so, how that might be accomplished?

    (Note: I should have said 12A in the title, as that is what I understand is the PIP draw.)
     
  2. seilerts

    seilerts Battery Curmudgeon

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    The kitchen GFI circuit would be your best bet. It is usually not loaded, unless someone is running the microwave, toaster, crock pot, etc. And if it overloads, the reset button is right there. The key, of course, and what many don't understand, is using a heavy gauge extension cord, minimum 12/3, preferably 10/3.
     
  3. greenleaf

    greenleaf Member

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    GFI protects against ground fault not overloading.

    There are some EVSEs that allows you to change the current. The Leviton L1 EVSE allows you to switch between 7A and 12A

    Portable Charger > Products from Leviton evr-green
     
  4. evfinder

    evfinder Member

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    I took a look at the one on display at the LA Auto show and it didn't look to have a control on limit current. However, you should be alright to charge on a 110V 15 amp circuit unless the person has other things plugged in and running on the same leg. The car will probably not pull more than about 13amps so unless the ciruit is badly overloaded it should be OK. It kind of depends but it is no more strain on the circuit than say plugging in a space heater if you use the supplied 110v charging cable.

    Noel
     
  5. usbseawolf2000

    usbseawolf2000 HSD PhD

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    According to the Japanese production model spec, the battery can store about 3 kWh. We can work backward from the charge time (3 hours) so about one kWh per hour.

    On 110V, that's about 9 amps. With charging loss, it should pull around 10 amps.
     
  6. PRPrius

    PRPrius Active Member

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    As I am not an electrician, I hope someone here can answer this questions for me.

    I have a dedicated 120v outlet in my garage that has a 20 amp circuit breaker. This is an outlet that we had the builder add in case we decided to add a freezer in the garage (Never happened). Will this outlet work with the Prius Plug in?

    Second question:
    The 20 amp circuit says 120/240v, does this mean that an electrician can change the outlet to a 240v if and when I decided to install a level 2 charger?
     
  7. evfinder

    evfinder Member

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    Yes, a 20amp dedicated circuit will work perfectly well for the PIP

    You would need to get an electrician to look at this but if the circuit was set up as 240V divided into 2 120V legs at the outlet then it could be changed for a single 240V outlet but if the split is done at the distribution panel then new wiring would need to be run.

    Noel
     
  8. theiding

    theiding New Member

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    I have a single outlet in my garage plus a couple of lights. I am guessing there is nothing else on the circuit, but I don't know.

    Couple questions from the electrically challenged:
    1) How do I know the amp rating of my outlet?
    2) Only way to find out what else is on the circuit is to flip the breaker and see what stops working, right?
    3) Can I simply try charging the Pip on the outlet and see if it works? Or could that damage the Pip/circuit or be dangerous otherwise?

    Thank you very much for any help!

    Mark
     
  9. greenleaf

    greenleaf Member

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    Generally the amp rating of the outlet is determined by the wire (with a matching breaker). E.g. 15A breaker for #14 wire, and 20A breaker for #12 wire. Just flip the breaker one at a time until you determine which one powers that outlet.

    The breaker would trip if the load(s) in the circuit exceed the rating. For continuous loads, you are not supposed to exceed 80% of the rated value. E.g. you should not put a continuous load of more than 0.8*15 = 12A on a circuit with 15A breaker.

    Running the 12A EVSE on a 15A circuit that also powers a few lights is iffy (are these shop lights?). You can add up the wattage of the lights to determine the overall current draw.

    For me, I am going to run a new 20A circuit to a new GFI outlet near to the rear of the PiP. I already have some leftover wire and GFI outlet from some previous work. I just need to find some time...
     
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  10. jbrad4

    jbrad4 Active Member

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    A little simple math.

    Volts X Amps = Power (watts)

    The literature for the PiP says that the battery will charge when completely drained in 3 hours. It's a little over 4 Kwh battery.
    If you figure that you only use or need to charge 80% of that, that gives you a required charge of 3.2Kwh over 3 hours. So that tells us the 120v EVSE uses about 1000 watts of electricity in an hour.
    1000 watts / 120 volts gives you a current draw of 8.3 amps.

    The 240 volt EVSE charges the PiP in half the time. So that's 2000 watts per hour.

    2000 watts / 240 volts = 8.3 amps

    So, the PiP will only draw 8 or 9 amps when charging at either 120 or 240 volts.

    I pay 9.5 cents / Kwh so it will only cost me around 30 cents per full charge to go 15 miles. Pretty good.
     
  11. bisco

    bisco cookie crumbler

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    unless you have a refrigerator, furnace, a/c or something that comes on automatically like that on the circuit, it should be fine. if it keeps tripping the breaker, you'll need to install a dedicated circuit.
     
  12. usbseawolf2000

    usbseawolf2000 HSD PhD

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    Ken already confirmed that 3 kWh from the plug is needed.

    The draw won't be linear as the charging will get slower toward the "full". I think we can safely say under 10 Amp, most likely the max is 9 Amp and will tail down.
     
  13. fuzzy1

    fuzzy1 Senior Member

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    (emphasis added) As an electrical type, this is one of my pet peeves. In this use, the highlighted words are redundant and unnecessary.

    'Per hour' is already included in the meaning of 'watts', the very same way 'and unnecessary' is already included in 'redundant'.

    'Watts per hour' does have a valid meaning in other contexts, but that meaning is not compatible with the general public and ordinary news media use of this phrase.
     
  14. iRun26.2

    iRun26.2 New Member

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    I think it makes the most sence to look at it from the viewpoint that a Watt is not a measure of energy, but rather, a measure of rate of energy usage. The related unit of energy is Watt-Hour where one Watt has been used FOR an hour.

    I do not look at the terminology described as being redundant. It is simply incorrect. When one says 'per' that implies division when, in reality, they should have used the term 'for' which implies multiplication (which is correct, producing the correct unit of Watt-Hour which is clearly what they meant).
     
  15. john1701a

    john1701a Prius Guru

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    This unit I had with an early test-model had a Test button on it, which supposedly did something to verify the outlet was ok to use...

    [​IMG]

    .
     
  16. greenleaf

    greenleaf Member

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    My guess is that the test button is probably a ground-fault test that verifies that the EVSE will shut off when a ground fault is detected.
     
  17. bilofsky

    bilofsky Privolting Member

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    Published spec for the 2012 PIP battery bank is 4.4 kWh, but it will never be empty at the start of charging.

    10 amps may be the average, but it will probably draw more current at the start of the charge, and less as it tops off.
     
  18. iRun26.2

    iRun26.2 New Member

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    Actually, it is 5.2 kW-hours.
     
  19. usbseawolf2000

    usbseawolf2000 HSD PhD

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    The prototypes had 5.2 kWh but the production model will have 4.4 kWh with 13% more EV range.
     
  20. evnow

    evnow Active Member

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    Nissan's L1 EVSE is made by Panasonic. I'd be surprised if the PIP one is very different. 12A is the max draw (IIRC).

    Ofcourse, you can always get it upgraded by Phile(Ingineer).