i have a 51 plate renault megan coupe expression. i replaced the battery earlier this year with a high power battery. went out and ended up trying to jump start a car off mine when i got back in the car the battery light was on and the stop light got home and parked the car up turned ignition off then tried to start it up again but after waiting for the normal lights to go out i only got a click from the ignition

marcus, December 2010

Wether you replaced it or not a battery is a very sensitive device and can easily be damaged. If you jumpstarted with your engine off then you battery has been damaged-(check voltage with a meter) if less than 12.2 then it is very likely the cause. We lose batteries in the system at work-vehicles refuse or struggle to start at 12.3 on the Range rovers.

Steve Walton, December 2010