Not sure if everyone knows or not, but the 3 level 3 charging stations (Kahala, Waipio, and Kailua) are now charging six dollars a session as of April 1, 2013
I hope this helps you.
As a comparison, I have driven from Mililani to Kalama Valley and back and returned home with one bar left.
The a/c was on the entire drive and average speed on the freeway was around 60mph.
I sent the following email to the city complaints department regarding the problems EV drivers face when parking at a city municipal lot.
Aloha,
I have parked in several City & County Municipal parking lots, and
have been charged for the parking even though I have a Nissan Leaf...