I have the following in my car and really haven't noticed any ill effects. I have a Kenwood KAC-X4R and KAC-X1R (bridged at 1 ohm) and I haven't had any issues yet. I ran 4 gauge wiring from the battery to a distrubition block, and 4 gauge into both amps. In all honesty, I didn't buy the car for the gas mileage (though it is a plus) and I plan on dynamating the floor, doors, rear deck lid and trunk. I will be using dynamat extreme. I AM NOT dynamting the the car for sound quality (though it will be a night and day difference) but I want to get rid of the road noise. I commute 25 miles each way (i have hov access) so I would like to have a quieter ride. I don't have a loud system, just clean and accurate. It really makes the commute that much better. I think after it's all said and done, I might have added another 50 pounds to the car.

Jayhawker: Do your lights dim at all? Do you have a lot of forced battery regens?

I really haven't noticed my lights dimming, but then again I am not pounding the system with a bunch of bass. It's rarely listened to the volume over half but it's nice to have the extra power there when I want to jam out on a song.

Hi ajhuntsman;

Sorry it took me a while to get a hold of your question - these Hybridfest trips can take a toll on one's schedule.

The HCH-II is an extremely poor platform to support the kinds of demands and 12V subsystem loads that a powerful audio system will call for.
To put it in the most basic of terms, the design faithfully follows the "minimal optimum" principle or "machine minimum, man maximum" Honda philosophy in that the system has barely any power headroom left for after-market devices unless you are willing to take on an ever decreasing fuel economy or you supplement the missing charge through other means.

If you live in a predominantly moderate climate and the power signature of the device is reasonable you may not have any issues at all.
If you live in a colder climate (winter time) then your 12V battery will undoubtedly have a shorter life and you may end-up experiencing IMA related malfunctions sooner or later.

The battery should be good for the occasional short lived demand of peak current. However, even a non-stop 100-200 mA is enough to bring this battery down in matter of a few weeks so it all depends on whether you operate the equipment with the engine off or not and for how long. Your commute distances also have a bearing. Shorter distances are usually worse.

The charge rate/frequency is managed by the car and the DC-DC gets its power primarily from the battery pack. On a moment's notice the DC-DC inverter can provide all the current you need but not in sustained mode.

I would avoid running more than 100 watts (approx 8 Amps) on a regular basis.

Cheers;

MSantos