Renault Grand Scenic 2010 MKIII (I believe).
I've had this problem for 2 years now, I had battery replaced and had it tested several times but no one seems to find the issue.
There is no clear pattern, neither temperature nor usage seem to be the issue.
I will be driving and "Charging battery fault" will appear on the dash, flashing a red warning. It usually disappears within less than a second, sometimes it remains there for a few seconds.
Previous battery was tested and was told that voltage was wrong and changed the battery but problem continued to happen.
If it happens several times on the same day, whenever I turn the car off it will give me the warning that the battery is low and to turn on the car. When I do that, the message changes to "Battery charging" and after a while it disappears (unless the error keeps showing up). This will happen for a few days and then just disappear and be gone for months.
Last time I ran the diagnostics on the car, I was getting an error on the radio, related to earthing failure. I occasionally get static (I assume) shock when leaving the vehicle (mentioning this as also electrical related). When driving, for some time the radio would just turn off for half a second and restart. Integrated sat-nav has developed two white lines on the screen (dead "cells") and for some time (same period of time when the radio was playing up) would start announcing that I had arrived at my destination when none was set.
I know this is Karma for getting a French car but....please help :)