2002 Volvo S40 Alternator charging

ZSELECPE

MEMBER
2002 VOLVO S40
4 CYL
2WD
AUTOMATIC
15,000 MILES

How long does a car need to be run (or engine to be idling) to re-charge a battery which has gone mostly dead but has been jumped successfully? Thank You, Pete z.

Tuesday, August 25th, 2009 AT 9:07 PM

1 Reply

MHPAUTOS

MECHANIC
31,937 POSTS

Hi there,

With the car idling you will only get what is called a surface charge, this is not enough to normally get the car going if you turn it off, at least take it for a long drive so the alternator can charge at peak volts, remember that the alternator is not designed to fully deep cycle charge a battery from a fully flat stat, it is designed to keep the battery topped up while demand is placed on it from all the systems that it feeds.

Mark (mhpautos)