I drive this 2005 Honda Civic Hybrid and get on average 47 mpg.
What I would like to find out is whether I can add one or two more batteries that I can re-charge by plugging in to a 110V or 220v electrical socket at night.

Does anyone knows anything about it ?

 

Unfortunately, the HCH doesn't allow you to do that. There are companies like Hymotion and CalCars that do this to Priuses and Ford Escape Hybrids. Unfortunately, the IMA system only allows the electric motor to run when the combustion engine is running. Right now, these conversions are expensive and void the cars warranty. Check back in 2 or 3 years when the car companies are producing them. Chevy has announced their Volt (2010), Toyota has announced a Plug-In Prius Fleet Program (2010), and Fisker has announced a Karma Plug in Hybird. Try searching around for more info on Plug In Hybrid Electric Vehicles (PHEVs).
It actually would be possible to add a couple of rechargeable batteries and tweak the IMA software to help you get better MPG. However, no company is doing it right now, so you would have to do it yourself. You would need to know a LOT about electronics, battery installation, cars, hybrids, and how to reprogram a HCH's computer. You are definitely thinking on the right track! Hopefully your next car will have a plug! (mine will...)
For more information on PHEVs and EVs, you can also visit us at www.pluginamerica.org. We have a ton of information on all types of plug in cars.

 

Thanks a lot for the information. This provides a good insight into whether this is possible or not at the moment and under what circumstances.

Thanks again.

 

Not to threadjack, but I was thinking about something along these lines too for my HCH1 but far simpler.

I'd like to drop one (maybe two) deep cycle 12v batteries in my trunk to run the 12v accessories. I'd charge these up at home from the wall. I know there are some folks with non hybrid cars doing this (read them over at ecomodder) but can't find anyfolks with HCH doing so.

Anyone else doing this already with an HCH? Does the extra weight of the Deep Cycle battery defeat the purpose of fuel savings? Besides the obvious of "in car entertainment" how easy is it to power the additional 12v accessories?

I have a background in component level electronics, but mainly as a tech, not doing design.