FORD 2013 F-550 v.1 - Manual (Page 316)

Battery Management System (If Equipped)
The battery management system (BMS) monitors battery conditions and
takes actions to extend battery life. If excessive battery drain is
detected, the system may temporarily disable certain electrical features
to protect the battery. Those electrical accessories affected include the
rear defrost, heated/cooled seats, climate control fan, heated steering
wheel, audio and navigation system. A message may be shown in the
information displays to alert the driver that battery protection actions
are active. These messages are only for notification that an action is
taking place, and not intended to indicate an electrical problem or that
the battery requires replacement.
Electrical accessory installation
To ensure proper operation of the BMS, any electrical devices that are
added to the vehicle should not have their ground connection made
directly at the negative battery post. A connection at the negative
battery post can cause inaccurate measurements of the battery condition
and potential incorrect system operation.
Note: Electrical or electronic accessories added to the vehicle by the
dealer or the owner may adversely affect battery performance and
durability, and may also affect the performance of other electrical
systems in the vehicle.
When a battery replacement is required, the battery should only be
replaced with a Ford recommended replacement battery which matches
the electrical requirements of the vehicle. After battery replacement, or
in some cases after charging the battery with the external charger, the
BMS requires eight hours of vehicle sleep time (key off with doors
closed) to relearn the new battery state of charge. Prior to relearning the
state of charge, the BMS may disable electrical features (to protect the
battery) earlier than normal.
CHECKING THE WIPER BLADES
Run the tip of your fingers over the edge of the blade
to check for roughness.
Clean the wiper blades with washer fluid or water
applied with a soft sponge or cloth.
Maintenance 315
2013 F-250/350/450/550 (f23)
Owners Guide gf, 1st Printing
USA (fus)