does anyone know or is there a previous discussion on what electrical componets uses the 12v battery and what uses the ima battery pack. Is there a inverter that charges the 12v bat from the battery pack. I assume that the headlights and other normal 12v accesories are on the 12v but is the electric a/c unit 12v. What tells the ICE to run to recharge batterys and does it monitor both battery systems to maintain proper voltage for each. It seems like a lot of drain would take place on the 12v system at night with lights,a/c,blower,and other acc. and its such a small battery.With these requirements its seems a deep cycle battery would be more appropriate.Hope somebody can explain this to me. thanks

Its really quite simple. The auxilliary 12v battery powers everything that it would on a non-hybrid Civic. The battery pack powers the electric motor.

The only interface between the battery pack and the 12v battery is a voltage converter that is used to charge the 12v battery, instead of the alternator in a non-hybrid. I think. It's not an inverter because an inverter commonly uses DC to produce AC.

2006 HCH Alabaster Silver w/Navi
2003 Honda Accord LX

One other difference vs. non-hybrid civic, though... I believe the 12v battery is NOT used for ICE starting (though it can if the IMA battery is too low).

Let me get this straight. When in the auto stop mode all the 12v componets are running off the 12v battery which in turn is being charged by the high voltage battery
Im not sure but I believe when changing DC voltages you make it into AC first to increase or decrease it.

When you auto stop, the IMA battery is powering everything thats on. Thats why its level of aggression in regards to auto stopping varies with the IMA battery level. What I've noticed is that I can autostop for MINUTES, and the IMA battery level doesn't seem to go down. This is for one of two reasons that I could think of: A.) one bar of IMA battery is worth maybe 5 to 10 mins of autostop, or b.) the conventional battery eventually helps out, takes over, or some combination of this. And yes, the IMA battery has an integrated starter that is used to start the car. However, I DID leave the lights on one day, and so the IMA battery died, and the conventional battery had to start the car. So it does help the IMA starter if need be. I know because I remember when the car did start after not starting for a minute, the IMA had shown NO bars, nothing. After driving it for a couple of minutes, it charged back up. Can't imagine what would have happened had I killed a few cells in there....

I haven't looked at schematics for the HCH, but this makes no sense. The wiring for all the accessories in the car - radio, headlights, gauges, etc., is the same as for every Civic. They are wired to the auxilliary battery.

It's possible that the auxilliary battery gets recharged constantly from the NiMH battery pack, whether the ICE and electric motor are turning or not. I don't know if that's the case, but it would explain what happened to you.

Well, yes, the hybrid motor is the integrated starter if that's what you want to call it. There is no separate starter motor associated with the IMA. When your car died the auxilliary battery didn't "help the IMA starter". It used a conventional starter motor that exists in the car, and is rarely used. That starter is hooked up to the auxilliary battery as in any other Civic and is independent of the IMA.

2006 HCH Alabaster Silver w/Navi
2003 Honda Accord LX

Check this out, I'm sure the Civic is similar:

http://www.insightcentral.net/encycl...converter.html

The main pack does hold the charge on the 12V battery. They are linked so it is hard to understand which is actually providing the power.

That's a method that's used for some industrial AC motor drives - convert AC to DC then back to AC - gives good motor control for the specific application. But in this case they are probably just using a simple voltage divider to convert the ~148DC volts in the IMA pack to the ~12 DC volts needed to charge the aux. battery. No need to go to AC then back to DC.