Auris Hybrid - 12v batt problem

[RDP]

Hi,

My 2013 Auris Hybrid has a problem with the 12v Battery. I can normally unlock the car but unable to start it. The last time I tried, the car unlocked but the wing mirrors did not unfold completely - so I assumed the 12v Battery to be flat. But after testing it there is a full 12v across the terminals. And my trickle charger indicates it is fully charger. What is going on? (Garage shut at the moment due to coronavirus). 
Thanks in advance. 
Richard

[Bob110023]

The volt meter can show 12volts at the Battery terminals but when the Battery is asked to produce the starting power etc the 12volts could well drop to well below 11 to 12 volts. This is because the Battery cannot deal with the excessive load required probably due to maybe internal cell fault or the just the end of its natural life.

[Cowdenite]

If the car is a Hybrid the 12v Battery does not start the engine the traction Battery does so there is no great power demand on the 12v Battery it’s used start the electronic systems.

[MagicBoy]

^^^ This. 12V is a tad low, they'll tend to show at least 12.7V when healthy IIRC.

7 years seems about average for the lifespan of a 12V Battery.

[RDP]

Thanks all - I think a dodgy Battery must be the problem and as Bob says - it can’t provide the current draw when it’s needed.