Has anyone done the "Big 3" upgrade?

Someone please correct me if I'm wrong... but I didn't think the Prius family had alternators... I thought the battery was charged using the Hybrid battery...

 

This does not apply to any Prius model. If you go ahead an try it, please post some picks of your car being pulled onto the flatbed... Then, take a picture of the look on your face when they tell you how much it is to fix it, you no longer have a warranty, and your insurance won't cover the total loss.

 

If you are going to power a 5KW power Amp, this may help.
But the Prius does not have a 5KW inverter, only 1KW.

 

The OP referred to an article that is based on non-hybrid achitecture. The Prius has no alternator... There are tons of posts on here about people adding amps, but the OP clearly has no understanding of how a Prius is designed and therefore, appears to have done ZERO research on the basics of their vehicle. My intial post reflects that! We are all here to help and teach, but, you can't teach someone how to do Algebra if they haven't taken the time to learn to add, subtract, multiply and divide! Just sayin'...

 

Exactly.

Prius has no alternator. The engine and inverter are grounded very well. The wire to the back battery however is weak. To run a big setup, you will need to run your own cable from front to the rear.

 

I want to make sure you are absolutely certain that you should NOT be touching the hybrid battery. If you connect "hybrid battery positive to battery positive" you will send 260 volts DC into something rated for 12 volts. Toyota goes through great lengths (for safety and longevity reasons) to have 0 physical contact between the hybrid (also known as "traction") battery and the rest of the car when not on. NO wiring should be made to that connector. The only exception is if you are advanced user and are running a PriUPS or something, which you are not.

Lets say you want a 1000W system, amp in the hatch area, maybe under false floor or something. The 12v wiring is not capable of sustaining 1000W continuously as it is stock. However a 1000W system will rarely ever get to 1000W. Unless you are entering the competitions where they crank the volume to max and then play a perfect tonal sine wave to purposefully strain the speakers and amp as much as possible, you will probably be drawing half that power at most during normal usage. At about 250W most people's ears start hurting. At 400W, it is physically painful to be inside the same vehicle with the same air being vibrated.

If your intent is good sound, something more powerful than stock that you can crank up and listen to music without setting off your neighbours car alarms, then just tie it directly to the 12v auxiliary battery. Since the battery is also in the hatch, it will absorb the theoretical 1000W pulses and recharge when normal sound is played.

If you want to go Mike Holmes on it, then you will need to run at least 4awg wire from under the hood to the hatch and connect to that. The 12v connection should be made at the inverter, right by the fusible link. You should then run another 4awg wire (or even thicker, ground cables for audiophiles are usually lower gauge than the positive) to the inverter and ground it to the inverter's chassis.

Use these for your amp.

No engine grounding since the engine is not producing power. All power is being routed through the inverter. No need to ground the inverter to the chassis because you should be running a separate ground wire. And in truth, it is already grounded really really well. In today's cars that are spot welded on all the body bits that make up the chassis, you will never get a better connection to ground through the chassis than through a dedicated low gauge wire.

 

4 GA is > sufficient with 900 watt digital amp from 12vdc battery and for amp case ground on my 2010. Don't forget to fuse it.

frodoz Stereo Upgrade | PriusChat

 

Back in my old car stereo days, we never ever attached to the alternator, always the battery. Why not in this case? (the 12v battery that is). The battery should act as a cushion to a spike in amperage demand from the inverter should it not? I know if you direct attached an amp to an alternator and cranked it up at low rpm's you'd kill the alternator. Will the inveter just respond to any amperage demand? Is there a limit to it's max output? (all questions, not trying to be smart).

Just checking.. First hybrid car for me, but tons of car audio experience (I'm old and don't mess with it much now).

Past MECP installer, worked for Clarion for 5 years, did SPL and SQ challenges etc..

 

That is true. However in "normal" cars the alternator and battery are pretty close. So thick wire between the alternator and battery and then battery to the back. But in the Prius the inverter can output 1000W continuously at 12v at any time the car is READY independent of RPM or battery charge. To run more than 1000W you should use the battery as a buffer.

But the battery terminals in the Prius are very small and so is the capacity. It will be a PITA to put the cables on the battery.

 

Thanks for the info!

C

 

Slightly related question... but I am having a miserable time with the little plastic plugs that go into the rear seat compartments that connect the battery. I follow the directions exactly on how to put the plugs back in. I take 5 of them off, spend 30 minutes getting 3 of them back on snug, and the other two are just hanging loose. What a PITA indeed. The instructions are very unclear on just exactly how the plugs are supposed to go in. I spin the plugs and orient their tilts from all angles and they're not going in to anything. I've already bent one of the sides of one of the plugs so much that I'm not even sure it'll go back in if I take it out again. Does anyone have any explicit directions (better than the manual) on how to get the plugs back in correctly?

 

WOW! I wanna see the video of this installation

 

That would not hurt. I think you could upgrade the positive that goes from the dc/dc converter (hybrid alternator) to the 12v battery too. The dc/dc is carefully managed by the hybrid computer and liquid cooled. If you do somehow fry it , which seems unlikely to me just remove all the wires you added. Dc/dc is under the hood.
What you would really need to upgrade to run big stereo is a more powerful dc/dc and fatter 12v wire through out. Upgraded dc/dc is probably not feasible.


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Good information, somewhat harsh at first as the initial question is 'normal' car based.

In a 'normal' car the alternator is bolted to the engine, so the engine is part of the electrical path. Since this is not true in any Prius, it is much less important to add extra ground wires to the engine. Extra grounds to the Inverter would be the equivalent procedure. (1 of the 3)

In a normal car, alternator output varies with engine RPM, so the battery acts as a buffer. In my feeble testing, Inverter voltage is a constant once the car is READY. And the battery is so undersized, it is not much of a buffer. Battery - to chassis should be easy if you find 2 gauge wire with a JIS post. (2 of the 3) The battery + wire should be much longer, (although not as long as other Prius) finding a pre-made cable seems unlikely. I doubt many kits will include that long a wire. (3 of the 3)

If it was my project, (and I never play loud music, so it isn't) I would find a location in the far back for a big 12 v battery, and wire my electronics to it, then wire it to the Inverter. That way you get the more normal SAE posts for your wiring kit, a bigger buffer for your amp and if you include an isolator, no chance of needing a jump.

(Here is an example. Not the parts I would choose, but those are the kind of parts you would need)
WARN 77977 Dual Battery Control Kit : Amazon.com : Automotive