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Power sockets only 10 amps. Is this "normal?" What's it fused for?

Discussion in 'Gen 4 Prius Main Forum' started by dpbsmith4, Apr 29, 2016.

  1. dpbsmith4

    dpbsmith4 Junior Member

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    So I just had to return a combination tire/mattress pump that looked great because--box didn't mention this!--the directions inside said "For use with 12 volt DC power outlets rated 15amps or higher. Do not use with older 8 amp cigarette lighter receptacles."

    What's the norm? Are the "10 amp, 120 watt" sockets on the 2016 Prius substandard? Do they have fuses or self-resetting circuit breakers?

    (We will be relying on the power outlets for too many things on our upcoming camping trip to take a chance on blowing a fuse).
     
    #1 dpbsmith4, Apr 29, 2016
    Last edited: Apr 29, 2016
  2. alanclarkeau

    alanclarkeau Senior Member

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    I don't know what the latest standard is. My 2011 FORD has 2 which are both 10 amp, my KIA 2007 was 10 amp, though I know of a 4WD which had a 10 at the front and a 15 at the cargo area at the time.

    You could ask your TOYOTA dealer for advice.
     
  3. wjtracy

    wjtracy Senior Member

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    Don't forget Prius is ideal for hooking up Inverter to the 12v battery for running outlets. There does seem to be a mismatch between how much power you can pull from the cig lighters (in the Inverter instructions) and the 10 Amp rating. To get full power to the inverter you switch to direct attachment to the 12v battery terminals. Gen4 I guess slightly new ball game (battery under the hood).

    Max cigarette lighter inverter question | PriusChat

     
    #3 wjtracy, Apr 29, 2016
    Last edited: Apr 29, 2016
  4. Geo13647

    Geo13647 Junior Member

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    12v @ 10a (120w) per cigarette lighter style outlet seems to be the norm nowadays.
    Actually, maybe it always has been, it just never used to be labelled for capacity.
    Most 12v accessories that are fused in the plug, have a 6a fuse, of course there are exceptions.
    Anything above 10a (eg, ham radio transceiver >22 amps) needs to be directly connected
    (via suitable in-line fuses) to the 12v aux battery.
    If it needs to be removeable, then a Hella style plug,
    or for higher currents, Anderson Powerpoles may be a good option.
    Again, suitable inline fuses need to be used.

    Well, that's just been my personal experience over the last 40 yrs. YMMV. G...
     
  5. dpbsmith4

    dpbsmith4 Junior Member

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    I found and opened the fusebox under the hood--which had a diagram and a fuse-puller tool under the lid, nice!--and one was labeled "15A P/OUTLET NO. 2".

    So apparently the socket says 10 amps but is fused for 15 amps.

    Curious.

    I never did find the one for P/OUTLET NO. 1. Maybe that's in the fusebox near the steering wheels. That one was so hard to see and get to that I decided to pass on opening it.
     
  6. wjtracy

    wjtracy Senior Member

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    So bottom line dpb?
    Maybe you would have been borderline OK with the air pump?
    Also possible some on the Prius 15A some are 10A?
     
  7. dpbsmith4

    dpbsmith4 Junior Member

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    I have no idea. But I've bought some extra 15A fuses. And I've bought a different air pump that doesn't actually say anything about the socket, but says that it has an "operating" current of 9.8A and a "maximum" current of 15A and we will try it out and see what happens.
     
  8. alanclarkeau

    alanclarkeau Senior Member

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    http://www.toyota.com/t3Portal/document/om-s/OM16W1QRG/pdf/MY16PriusQRG.pdf page 19 indicates there are 2 outlets.

    My house has 34 10A outlets - but 2 circuits of 15 amp each. But I can't plug in 34 10A appliances in at a time.

    For the normal things (fridge, TV, DVD, computers, lamps, clocks, phone charger, radios and most small appliances etc), this won't cause a problem - but if I'm vacuuming while the clothes dryer, iron, toaster and frypan are on, a circuit breaker may trip. Only happens every few years, but is possible.
     
  9. kithmo

    kithmo Couch Potato

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    You really must vacuum more often Alan :rolleyes:
     
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  10. alanclarkeau

    alanclarkeau Senior Member

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    Oh, no - I bought a large grand piano (part of which is showing behind my (non-shedding) dog in my Avarar), so less dust falls on the floor (or I can't see it under there?).
     
  11. cherrydave

    cherrydave New Member

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    A 2016 Prius has two DC power outlets. Which outlet should I use to charge an oxygen concentrator that can draw as much as 19A? The outlet located in the front seat or the outlet in the rear seat? The circuits are separate and each has a 15A fuse. One circuit has a relay in it. Is Power Outlet 1 in the front seat and Power Outlet 2 in the back seat or vice versa?
     
  12. Prodigyplace

    Prodigyplace Senior Member

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    Neither power outlet has wiring heavy enough for that application. I also doubt that type of socket is designed to handle that high a current.
    You need an automotive professional to install a circuit and connections heavy enough for that application, if they deem it safe for your car.
     
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  13. cherrydave

    cherrydave New Member

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    Thanks. Not that it matters but I made a mistake in my original post. The input device current maximum is 18A and not 19A. I've tried it in both DC outlets and it charges the concentrator but very slowly. Do you happen to know if Outlet 1 is the front seat outlet or the rear?
     
  14. wjtracy

    wjtracy Senior Member

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    I presume it is analogous to the idea of hooking up a 1000W inverter to the battery to power the house in an emergency...that connection must be made directly to the 12v battery. If you have a real small inverter than you can hook up to the cig lighters. My 300w inverter comes with cig lighter or battery clips depending on how much juice you need.
     
  15. Elektroingenieur

    Elektroingenieur Senior Member

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    It’s usual automotive practice to size fuses and wiring so that the expected load is not more than about 70% of the fuse capacity. Readers familiar with the National Electrical Code, for wiring in buildings, will recognize the similarity to the 125% rule of NEC Article 210.19(A)(1)(a).
    I agree with @Prodigyplace that neither outlet is suitable for this purpose, whether it draws 19 A or 18 A. The limit stated in the Owner’s Manual (10 A/120 W) is reasonable and shouldn’t be exceeded.

    Indeed, I wouldn’t recommend adding substantial, continuous loads, no matter how they are connected. Remember that the Prius does not have an alternator; instead, 12-volt power is supplied by a DC-DC converter in the hybrid system, which has a maximum output current of only 100 A, according to Toyota’s New Car Features book (available by subscription to techinfo.toyota.com). More current is available, of course, but only for a limited time, since it comes from discharging the auxiliary (12-volt) battery, which must then be recharged.
    The Electrical Wiring Diagram (also on techinfo.toyota.com) shows that the No. 1 Power Outlet Socket Assembly (F45) is in the front, and the No. 2 Power Outlet Socket Assembly (F47) is in the rear.

    Both of these outlets are switched by relays. The fuse for No. 1 is fed directly from the ACC relay, and the coil for the P/OUTLET NO.2 relay is energized from the ECU-ACC circuit, which is also fed from the ACC relay. The main difference between the two outlets is that No. 1 is both supplied and switched by the Instrument Panel Junction Block Assembly, so its current passes through the JB-AM (60 A) fusible link, while No. 2 is only switched there, since it has its own fuse under the hood and wire through the firewall.
     
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  16. alanclarkeau

    alanclarkeau Senior Member

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    You mention to "charge an oxygen concentrator". How often does it need charging? And how long it the charging cycle?

    Is it say like an electric toothbrush which is on charge for a few hours every few days, or a smartphone which ... well mine needs regular charging, but it's old.
     
  17. Prodigyplace

    Prodigyplace Senior Member

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    To answer the original subject question, yes 10 amps is normal on any modern car.
    Charging an oxygen concentrator from a car is not normal and outside the car's designed parameters.
     
  18. wjtracy

    wjtracy Senior Member

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    Here is a thread that talks about getting more power via inverter hook-up to Gen4 12v battery
    1000w 12v Power Inverter on Gen 4 Prius | PriusChat

    The Gen4 has the 12v battery under the hood, so it is perhaps less convenient for this purpose. For Gen2 and Gen3 it was common to hook up and inverter to the 12v battery in the hatch, and power fairly heavy loads to the house during weather emergencies/power failures. Of course the vehicle is left on during this period so the hybrid system keeps charging the 12v.
     
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  19. alanclarkeau

    alanclarkeau Senior Member

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    Yes, something I missed in my previous reply. My last 2 cars, 2007 & 2010 FORDs had 10amp outlets.
     
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  20. David Beale

    David Beale Senior Member

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    There is a reason the "cigarette lighter" plug is limited to 10A. It WILL overheat at higher currents. Fires have been caused by this. This is why Amateur Radio people are encouraged to wire directly to the battery, with an inline fuse at the battery. Heavier wire (#14 minimum, #10 prefered), proper connectors rated for the current etc. makes a big difference.

    The worst possible outcome is caused by the voltage drop in the wiring and connector (cig. lighter plug) causing the load to draw even higher current, dropping the voltage even lower, causing even higher current to be drawn, causing things to heat up rapidly, melting plastic parts and eventually causing a fire. You don't want this.

    Install a proper cable from the battery, with inline fuse at the battery, to be used ONLY when the car is in "ready". You can even install a relay in line with this cable, closed by "accessory" voltage, ensuing the cable won't work unless the car is on. Something I always do.