Well my hubby's good mates at Autofficina took a look at my Ruby today, the battery is not getting above 11.5 volts when car is not running. Even though the battery has been trickle charged, it still won't hold a full charge of 12.5 v
Looks like a cell has gone (hence drop of 1 Volt from norm) ....... basically knackered.
Alternator is fine - charge is 14.25 volts when car running...........so definitely the battery at fault.
Battery - also looks like wrong size for this model - battery is too small. Looks like the bracket has been moved to the coupe position - see that battery holder is on the small battery setting not the large one note: convertibles have bigger batteries on the bmw to cope with hood mechanism.
Learning all the time!! at least the warranty will replace at no cost to me. Other than this I've had no problems and still a happy bunny!
Looks like a cell has gone (hence drop of 1 Volt from norm) ....... basically knackered.
Alternator is fine - charge is 14.25 volts when car running...........so definitely the battery at fault.
Battery - also looks like wrong size for this model - battery is too small. Looks like the bracket has been moved to the coupe position - see that battery holder is on the small battery setting not the large one note: convertibles have bigger batteries on the bmw to cope with hood mechanism.
Learning all the time!! at least the warranty will replace at no cost to me. Other than this I've had no problems and still a happy bunny!
its a generic tray used in larger bmw vehicles which use a larger battery 
I'll leave it to the experts as I am certainly no mechanic!! :!: