Volvo XC40 Owner's Manual page 556

MAINTENANCE AND SERVICE
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Negative connection point
Positive connection point
CAUTION
Only a modern battery charger with con-
trolled charge voltage should be used to
charge the starter battery and support bat-
tery. The rapid charging function should
not be used as this could damage the bat-
tery.
554
CAUTION
Failure to observe the following could
cause the infotainment energy save mode
to temporarily stop working and/or a mes-
sage in the driver's display regarding the
state of charge of the starter battery may
be temporarily incorrect after an external
starter battery or battery charger has been
connected:
The negative battery terminal of the
•
vehicle's starter battery must never be
used to connect an external starter
battery or battery charger – only the
vehicle's negative charging point
should be used as a grounding point.
NOTE
If the starter battery becomes discharged
too many times, it will shorten its service
life.
The service life of the starter battery is
affected by several factors, such as driving
conditions and climate. The starting
capacity of the battery reduces gradually
over time. The battery must therefore be
recharged if the vehicle is not used or a
long period of time or if it is only driven
short distances. Severe cold further limits
the starting capacity.
To keep the starter battery in a good condi-
tion, the vehicle should be driven at least
15 minutes per week or the battery should
be connected to a battery charger with
automatic trickle charging.
A starter battery that is always kept fully
charged has the maximum service life.