My 2004 HCH had this problem - I posted about it somewhere back in May. Turns out my 12v battery problem were completely unrelated to the hybrid system even though the lights were saying it was. The problem on my 2004 HCH was a bad A/C clutch relay. It would randomly stick in the "on" condition and when it did, it drew down the 12v battery's reserves. An $8 part and a month in the shop for evaluation. The shop charged only 1 hour labor.

It is working great now. We have driven it about 5000 miles this summer - so far - and our mileage from central Illinois to NE Ohio today (505 miles) was one tank of gas yielding 45+ miles per gallon.

Maybe your solution will prove as inexpensive though frustrating.
dsc

 

To shutchinson48:

Thanks for posting your situation with your Honda Civic Hybrid 05. I'm have the same car and the same problem. Our Honda dealership hasn't been able to figure out the problem, so they just took out everything after market (which was only the Honda installed car alarm/remote starter which I really miss), and told us it was fixed and didn't charge us. When we continued to have the same problem, we called them and they admitted that they hadn't charged us because the technicians test hadn't actually concluded that it was the alarm. They just took it out because it was their best guess. Now, they are saying that they have no responsibility for figuring out the problem because they haven't charged us and in general, they're being quite nasty about it.

I'm hoping to fix the problem by replacing the A/C relay like you suggested. I found a genuine Honda part for sale on autopartswarehouse.com for $37. Does this sound reasonable? Also, how many do I need? Is it something that I could install myself, or do I need to take it the Honda technician. I think they're going to give me a really hard time about it because they already treat us like we're stupid because I didn't know that Hybrids didn't have alternators (which I originally thought was the problem). Also, I was told that regular mechanics won't tough a Hybrid. Is this true? In that case, I feel like it was a bad idea to get a Hybrid. If Honda can't figure out the problem, they are forums like this our only chance??

Note: we also have the CVT replaced recently, another problem they refused to acknowledge until it got so bad the car was violently shaking every time I accelerated. I guess I need to find a different Honda Service team.....

 

Did your gas mileage increase after you fixed the relay problem? Our gas mileage is only about 34mpg on a good day. Most of our driving is in-town (Houston, TX), but I was originally told it was supposed to be better in-town. It actually seems better on roadtrips, but never anywhere near 45mpg. I'm jealous....

Also, thanks to these posts, I'm pretty sure that we're having a relay problem as well. The dealership just thinks that keep leaving lights on, but I'm not that stupid!!!

 

Stephanie, the dealer installed the relay which cost about $8.00. It is a user-friendly do because it is in one of the fuse boxes in the engine compartment by the battery.

Gas mileage... My 2004 has averaged overall from almost purchase new 41 and a fraction mpg. That's in town, and out of town. What I have noticed is that the summer is great! In warm weather, I can easily get 45+ on the highway if I stay around 65 mph. In the winter's cold weather, 37 or 38 is "good."

There was no change after replacing the relay.

Hope that helps.

 

Stefanie:
I bought the A/C relay from a Honda dealership parts department and the total cost including tax was $8.29. $35 is too high for the relay. I suggest you go to your dealer's parts department and just buy the relay yourself. It is very simple to install and you can do it in about 2 minutes. If you will email me, I will send you step-by-step instructions on the location and replacement of the relay. shutchinson48@hotmail.com

 

hello all i have a problem with my 05 accord hybrid it drove fine then one day it just wouldnt start so my firts thought was the starting battery so i charded the battery and the car started fine then i turn it off and it wont start then i turned my ignition like 5 more times and it started on the fift time then the next 10 times it starts fine then it doesnt start and while its sitting on the drive way my battery goes dead. does anybody knows what that could be? please let me know

 

It appears your 12V battery (the one under the hood) is weak. Replace it.

 

The best thing to do in this situation is to lay out entire schematics/diagrams of your electrical systems, both engine and chassis. Then start removing potential draws(temporarily overnight) if no short or faulty component is found, then and only then would I make the assumption your hybrid system is out of whack and either over or undercharging the batteries as you drive(a scan gauge will help) or is the actual source of the draw.

 

Was your hybrid IMA battery not charging properly? If so did the relay help? send me th info where the raly is located.