I would really like to install a nice aftermarket stereo in my new 08 Civic Hybrid. Are there any reasons why I should NOT draw current from the battery (under the hood)? Is there any thing special about the hybrid that relates to the hood battery?

I plan on running 0-gauge power from the battery to the trunk, splitting into two 4-gauge power wires, going into 2 amplifiers. The total RMS wattage would be about 1350, so peak wattage would be around 2500. The system will be professionally installed, and I will be using high-end wire and wiring components, like a fused distribution block.

Since I pick up my new hybrid on Monday, can anyone tell me the speaker sizes and layouts? I think there are 6.5" in the front and 5.25" in the rear. But are they coaxial or components? If they're components, where are the stock tweeters mounted?

 

Just remember, the 12V battery in the HCHII is WAY smaller than a standard auto battery. Big draw items like power amps in a stereo sytems rely on the sustained output from the car alternator, rather than solely getting power from the battery. The HCHII does not have a traditional alternator, this means that the 12V battery gets charged by the NiMH battery system.A heavy draw sound system could easily drain the 12V battery.

 

How exactly is the hybrid alternator different from a normal alternator? Is it possible to install a higher output alternator? I know it's expensive, but I want to analyze all my options before purchasing my stereo equipment.

In addition to an alternator upgrade, I could ALSO upgrade the stock battery to something like this:

http://www.sonicelectronix.com/item_...k+HC+1400.html

My plan is 440 watts RMS for the cabin speakers and 900 for the subs. I'd really like to have subs, but I might be able to live without them. In that case, I'd only have 440 watts which should be OK...

 

I believe there is no alternator in the HCH. The electric motor generates power to charge the high voltage battery pack then the battery pack charges the "under hood" 12v battery. You would probably have to add more higher capacity 12v batteries somewhere in the vehicle and find a way to charge them, maybe retrofit a heavy duty conventional alternator, 50-100amps, onto the existing engine belt. Adding weight and increasing power demand will also decrease your mpg's. Wow, you are looking at adding at least 100 amps to the system.... 1300 watts is almost 2 horsepower sucking off the engine. (Hope you own stocks in "Miracle Ear".) FYI, I'm totally deaf in my left ear from loud music...

 

I did verify with the dealership that there is NO alternator in the hybrid, and that the stock battery should be able to power normal 12v accessories. Of course, my stereo plan is not normal. I will plan on upgrading the hood battery to the model I posted above, assuming it will physically fit. Regardless of my stereo, going from 550 cold-cranking amps to 1500 will be nice to have for our Iowa winters.

They also said the hybrid battery packs are UNDER the rear seats, not behind them. I always thought they were behind the rear seats, which is why you can't fold down the seats. Weird.

Also, the tech suggested running power from the hood battery along the trim panels on the driver side, into the trunk. Apparently, once you remove the rear seats there is also a steel panel to be removed before you have access.

I could reduce the amperage draw by 1/3 by changing my sub amp from 900 watts to 400 watts. That would put me at a total of 840 watts RMS. I don't like the idea of retrofitting an alternator...

Has anyone else installed a medium or big system? Any battery issues?

 

I can guarantee you that you'll find it virtually impossible to put a physically larger battery under the hood. I couldn't even find enough room to install a 3.5 x 4.5 x 8 in Bypass oil filter. The battery is much smaller physically than a standard battery. It is 5.5w x 8.5l x 8.5h and there's not much room to modify the mount to take a bigger battery. At 9" x 5.3" x 8.1" the Kinetik battery is larger than the stock battery.

Even if you decided to go with an additional battery mounted in the trunk, you still come up against the lack of an alternator to sustain the high current draw of power amps.

This is not really a good car to attempt a massive output stereo system, especially if you want to maintain any decent fuel efficiency.

 

Good point. I know a hybrid isn't ideal for huge stereos, but I should be able to install something decent, even if I downsize my plans a bit.

This Kinetic battery is smaller than the stock battery, but much more powerful, and designed for car stereos:

http://www.sonicelectronix.com/item_...ik+HC+800.html

If I use that battery, and reduce my watts from 1340 down to 840, shouldn't I be OK?

Also, what about using capacitors, since they ease the burden on the battery? I know it's just shifting the burden rather than eliminating it, but at least my hood battery is less apt to get low...

 

It may be smaller cubic inch wise, but the physical length appears to be longer than the stock.

But the main issue here is that even with some power reduction, you'll still be putting a considerably higher load on the electrical system that doesn't have an alternator to sustain a consistent high level of output. The simple fact is that the electrical system has a limited, finite output and adding significantly to the current draw will affect your fuel efficiency and battery charging.

 

The cold cranking amps are pretty much a mute point. Most of the time the hybrid does not rely on the starter to start, the Hybrid system starts it up.
It would have to be very cold for the starter to actually come on line it is a rare thing to have happen.

The batteries are in fact behind the back seat, not under it...I suspect the dealer needs to learn a thing or two about the cars they sell.

Adding additional load to the engine just does not make sense, I understand you want a good stereo but do you really need 800+ watts while you are driving? I am an audiophile, but the car is just not the place for that kind of volume besides, it is the quality of the components not the sheer power output, a 50w properly rated amp can have better, cleaner output than a mass marketed mass produced 500 watt amp.

I suggest you change both audio & car dealers till you fing one that knows what they are talking about.

 

First, thanks for all the comments. I really appreciate the help.

Is there any way to precisely determine the recharge rate of the hood battery? If so, that would give me a good idea of the number of amps that I can safely draw without draining the battery.

I do care about quality more than volume. I was planning on big amps so I could leave the amp gains at 1/3 or 1/2, to keep them cool and avoid distortion. So in reality, I would not be drawing the amps' full potential.

I am willing to downsize my plans in order to have a "safe" install on my hybrid. If I use a 4x85 amp for the cabin speakers, that's 340 watts. I could live with that, and the car should be able to handle that easily.

The subwoofer amp is the big question mark. I originally planned on a 900 watt amp, but can use a 300 watt amp instead. If so, that's 640 watts altogether.

I've read online that at least a few people have big systems in their Civic Hybrids, but they didn't mention how big their amps were. So I know it's possible, but I don't know where to draw the line with my amps...