Ford Focus 2004 Owner's Manual page 190

Take great care to avoid
simultaneous contact of both
battery poles with metal tools or
inadvertent contact between the
positive pole and the vehicle
bodywork.
•
When reconnecting a battery
always connect the positive ( +)
cable first and then the negative
(–) cable.
•
After reconnecting the battery,
turn the ignition to position II for
30 seconds.
If the battery has been
disconnected the vehicle may
exhibit some unusual driving
characteristics for approximately
8 km after battery reconnection.
This is because the engine
management system must realign
itself with the engine. Any unusual
driving characteristics during this
period may be disregarded.
The audio system must be
reprogrammed with the keycode.
Used batteries contain
sulphuric acid and lead. On no
account must they be disposed of in
the household refuse. Use your
local authorised waste disposal
facilities.
Roadside emergencies
182