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Is it dangerous to install an amp in a Prius?

Discussion in 'Gen 2 Prius Audio and Electronics' started by merrill, Nov 16, 2005.

  1. merrill

    merrill New Member

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    Is it dangerous to install an amp in a Prius?

    My local install Tech told me they would not install an 800W amp into my 2005 Prius because the 12v auxiliary battery did not put out enough amperage to sustain the amp. They claimed it would cause too much draw on the battery causing it to pull from the main battery and the computer that lets the two batteries communicate would eventually burn out causing expensive major electrical problems. I have a 10yr 100K mi warranty that I do not want to void. Are their any existing cases where this has happened? Is it possible to install an amp and sub into my Prius? I have read many posts in this forum and it seems many people have installed aftermarket audio systems successfully. Should I be worried about damaging the CPU or the electrical system of my Prius?
     
  2. tmorrowus

    tmorrowus Member

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    Short answer: you should be fine installing that amp in the Prius.

    You should never run a big audio system for more than a few minutes with the hybrid system off, so the size of the 12V battery is of little importance.

    Nobody really knows the capacity of the DC/DC that powers the 12V system from the main high voltage system... if your tech has that info please have him tell you and us. But most folks have believe from the 100 Amp fuse that it's pretty beefy.

    If there was any damage it would be to the DC/DC converter, likely heat damage. There's no evidence this is likely or even possible. Or if you played the stereo off the 12V battery only too long you could kill the 12V battery, which is a real possibility (even with the factory JBL system). There would be no reason any CPUs would be damaged.
     
  3. tmorrowus

    tmorrowus Member

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    One other note... it is dangerous to install an amp into a Prius (or any other vehicle) if you don't do proper fusing... you can start a fire if your wiring is not done right. This is what I thought your question would be about when I read the subject.
     
  4. merrill

    merrill New Member

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    Thanks for the feedback.

    The tech I was talking to about the amp install said the 12v aux battery only put out 15amps, which is much lower than that of a regular 12v, and would not be enough to power the amp fully and would result in additional draw from main battery to compensate. I'm not sure if this helps or if you had that info already.

    Additionally, best buy said they would do the install for me no problem. They just want 60 bucks to do it. I feel comfortable doing it myself if not for the warning from the other installation guy.

    Thanks for the advice regarding the fuse, too.
     
  5. Presto

    Presto Has his homepage set to PC

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    I'm running about 500 watts RMS with no problems. I think the install tech is a bit ignorant to the way the system works as it's okay that the amp has to draw from the HV battery when the car is on. With an 800 watt amd, that would typically be the PEAK output so RMS-wise it'll probably do 2-400 watts which'll be no prob for the Prius.
     
  6. DanMan32

    DanMan32 Senior Member

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    If that were true, then the brake system/cooling system/power windows/etc wouldn't work unless you were in READY. Those things draw way more than 15A, and do work in Ig-On mode, where the HV battery is disconnected.

    Now it is true that the power outlets are fused at 15A, and rated for 120W nominal draw, but you're not going to tap from there, except maybe for turn-on current.
     
  7. tmorrowus

    tmorrowus Member

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    Yep, that tech sounds like he's conservative but not necessarily particularly knowledgeable.

    There's no question that running any audio system (aftermarket or JBL) for an extended period of time has the potential to be harmful to the 12V battery. But the 15A number doesn't really make any sense, not sure where he pulled that number from.

    If the 12V battery could only put out 15 Amps then it could only put out 12*15= 180W. The factory JBL amp puts out 45Wx4= 180W, and lets guestimate that it's 50% efficient so it uses 360W to do that. So by his logic using the JBL amp's 360W would overpower the 180W battery, causing some presumably hideous meltdown.
     
  8. IndyDoug

    IndyDoug New Member

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    It seems that your install tech is anti-Prius.
     
  9. Marlin

    Marlin New Member

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    Is it just me, or does 800 watts seem a bit excessive inside a confined space such as a car?

    I must be getting old I guess.
     
  10. datavortex

    datavortex New Member

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    My last car had over 2000 watts of amplification when you added it alll up. Now I am older and content with the stock JBL 45x4 + 150 sub = 330.
     
  11. tomdeimos

    tomdeimos New Member

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    There are power limits to the inverter of around 1Kw. And the battery can't handle all that much.

    The limit is actually like most cars or better, but we have electric heaters that can use up a lot of that power, so if they are on, the power for the audio could be limited. So you need to calculate your worst case loads.
     
  12. tmorrowus

    tmorrowus Member

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    Are you sure the heaters run off the 12V system? I would have assumed they would run off the high voltage.
     
  13. tomdeimos

    tomdeimos New Member

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    The heaters are 12 volts. Two for the cabin and one is for the power steering.
    I don't remember the wattages but the cabin heater ones are fused at 30 amps each,
    and the power steering one at 50 amps.
     
  14. KMO

    KMO Senior Member

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    But as I recall, there are some interlocks - the PTC heaters are deactivated if certain other high-current devices are active. I can't remember where I read this though - it's not in New Car Features.
     
  15. KMO

    KMO Senior Member

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    It all seems a little confused. But putting the info in New Car Features, the Repair Manual and the Wiring Diagram together, I think it is thus:

    Built right into the heater core itself are two 165W PTC heaters. Being integral, they're not really shown in the repair manual, but NCF illustrates them. They're treated as a single unit, routed through the 50A PS HTR fuse and relay. I don't know what "PS" stands for. They're normally activated whenever the engine coolant is cold, the climate control wants more heat than available from the heater core, or when the climate control is in Defrost mode and it's cold outside.

    In the footwell air ducts are two more 165W PTC heaters, one on each side. They are switched separately through two 30A PTC HTR fuses and relays, but the two relays are switched simultaneously by the A/C control system. They're normally activated whenever there is airflow through the foot vents, and the engine coolant is cold or the climate control needs more heat than available from the heater core.

    DanMan, where did you find the info on electrical load, btw?
     
  16. KMO

    KMO Senior Member

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    One pair is for heating engine coolant, defrosting and for cabin heat. The other pair is for cabin heat only. Only the latter are likely to be immediately felt, as they're right in the foot vents.

    The actual power is pretty meagre - they're only specced at 165W each, so that's 660W of total electric heating power. Compare to 5300W for the engine-derived heat, and 4500W of A/C cooling.
     
  17. SunTzu2024

    SunTzu2024 New Member

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    2016 prius c ds18 1600.4 .... kicker 2400.1. 2 kicker l7 12s, 4 rockford pro audio 8s in doors and 8 1 inch tweeters. Had to chage out factory battery with 280 ah lithiam. Works just fine.
     
  18. dolj

    dolj Senior Member

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    LOL. You're responding to a Gen 2 thread that is nearly 20 yo with information about a different model Prius. Maybe post in the correct Prius c forum?