Charging system !
 

I noticed that the needle goes to about 11-12 volt during stop or 900 RPM.
the weather these days very cold about ~ 4 c. night.
I changed my alternator before year with new one!
when the engine runing in normal codition say above 1000 RPM , the voltage goes and stay ~ 14 V.

q: is it possible IF the battery is weak ,even with engine runing the voltage can be drop as my situation??! :icon_scra
where is the problem you think guys?