Probleme voyant batterie sur F4 de 2008

oui je suis d'accord , mais a la page 21 de la notice technique il ya ça:

Electrical system
A list of possible problems that could occur when the warning light is switched on.


With the engine switched on at approximately
2000 r.p.m. check the voltage of
the battery (all utilities must be switched
off and the regulator at 25°C.); the voltage
must be 14.5V ± 0.6.
N.B. At different temperatures the voltage
can be between 13V and 15.5V.

merci pour l'info