Last week we had some problems with our G-wiz for the first time in three years of owning it. Basically it left me stranded about a mile away from home, could have been worse, it just meant I had to walk home. I got Ric of EV Workshop around to check it out and it turned out to be the charging chip that had somehow become corrupted, the gauge was reading fully charged but it was really very low, the chip had reset its self to only charge the car to 20%. Anyway, with a quick plug in of the laptop and a resetting of the chip the car is back to normal. Common causes of this chip corruption are a power surge when charging[power cut in the night] or over use of the boost button. If you own a  electric microcar I can highly recommend EV workshops, they are fast, knowledgeable and the costs are reasonable, the testing and chip reset cost me just £20 and the car didn't have to move off the drive. I think we got off very lightly indeed! Its a strange feeling though being powerless to fix my own car, apart from brakes and steering there is nothing I can tinker with myself, how I hate digital technology!! I still love the Wiz though.