Just how much can I install?

Uhhh, what are you trying to install? A sauna/hot tub... satelite dish...
submersable sprinkler well pump... combo washer/dryer... all of the above?

Yo, you gotta say what you're trying to do so folks can try to help.

Right now, you're coming across as a "random number" yourself!

 

welcome to the group.

I believe your limit is around 1000w of power.. i'm sure others will chime in with the exact amounts.

 

I think the Prius is the perfect car if you need lots of power.

But strongly consider a bigger battery if you will ever need much power with engine off.

Prius - UPS Project

Read the "UPS Testing" section. This guy was able to get 1000 watts or 80+ amps at 12 volts continuously with the engine starting and stopping as needed to maintain battery charge.

There's some speculation here http://priuschat.com/forums/prius-modifications/47346-110v-outlets-your-prius.html that you may be able to get more than 1000 watts for short term bursts anyway.


If you need/want more power you could tap the 200 volt battery for 3000 watts (perhaps more) continuous. See PriUPS-getting electricity FROM your hybrid vehicle . It may void your warranty and/or electrocute someone if your not careful, but it's possible.


Hmmm, 3000 watt sub-woofers. Reminds me of a Mythbusters episode where they turned an engine into a speaker driver...

 

PLPrius,

Hey man, you got it all wrong.

My post was meant to prevent the situation that has come about; folks here
don't know exactly what to say because you haven't given them good enough
info to work with. On it's face, my crack about a submersible sprinkler well
pump sounds outlandish, but one poster has provided you with threads that
suggest that you could do it.

There are many incredibly talented people here. There are also some only
just believable projects that are routinely discussed. Some examples:
* Hacking the power steering
* Adding an extra HV battery pack with maybe 300+ AA rechargeable batteries
* Running X-box, Wii, or some such on the MFD while underway.
* Using the Prius as an emergency generator

In every case, specific detailed info on the equipment is provided by the
poster seeking info/help. In your case I suspect it's on a data plate or in the
owner's manual. Look it up. Post it.

Believe it or not, you may know more about things electrical than I do.
Check this thread out:

http://priuschat.com/forums/prius-technical-discussion/42651-dead-12v-battery-glove-box-remedy.html

Pretty pathetic huh? (Ain't sparkyAZ a saint?)

The only reason I was able to move forward was the repeated, patient help
that I got from folks here. With a slight course adjustment on your part, I'm
confident the e-smart folks here will bend over backwards to help you.

If you want to attract bees, honey works better than vinegar...
but be prepred, a hornet or two may also show up.

At the risk of causing offense, I would suggest that you start a new thread with
a catchy, product specific title. Something like:
Bang & Olafson XYZ Woofer -- Will it Work?

 

The reason people asked for more information is because when you want to use the power is important to the answer. If you are using the power when the car is running then the size of the battery is irrelevant, the size of the charging system is what matters. Since you talk about subtracting the standard loads, it seems like this would be your question. On the other hand, you ask specifically about the battery. The battery capacity would only matter if you are trying to run your whatever with the car off.

This is true of all vehicles, hybrid or not. In a standard vehicle, the amount of available 12V power is determined by the alternator when the car is running, by the battery when the car is off. Same for the Prius, although the alternator is replaced by the DC/DC charging system. If you use more than the charging capacity then you will eventually drain the battery down to nothing.

The Prius has such a small battery because when you start the car all the 12V battery has to do is boot the computer, then the high voltage battery does the rest. In a "normal" vehicle the battery is bigger because it has to crank the starter. This results in the side effect that there is more power available from the battery when the car is not running.

Having said that, the 12V standard battery is specified at 28AH. In theory that means that you could draw 28A for one hour and the battery would go from fully charged to completely dead. In reality, you can only get about half that much out of a battery, and even that is not great for it on a regular basis.

On the other hand, the main 12V fuse is 100A, so, in theory, the charging system can provide up to 100A or about 1380W (typical charging voltage is 13.8V).

Then one part of the answer I can't give you is what the "normal" loads are in the car. Maybe someone else here has that answer.

Good Luck.

 

my prius tends to charge at 14.4 volts.

my observations are seen though the secret screen on the 04 and 05 models...

 

I'm installing a second car audio amplifier today (400watts rms) so that will bring my total up to 1,900watts rms or continuous as some perfer. This is for car audio purposes so rarely will I ever be running everying at peak current draw for very long. So far I have had no issues with the vehicle itself but the stock battery on the other hand, is on it's way out. I cannot play the system hard with the car off or it fails to supply the needed current and the system cuts out. This was with just the 1,500watt subwoofer amp alone.

I'll be adding a new battery soon.

 

I forgot about that, mine is 13.8 volts.