308 Maintenance Disconnecting and connecting batter- ies Reconnecting the batteries Observe the safety notes on handling batter- ies. Disconnecting the batteries ! Vehicles with BlueTec ® exhaust gas after- treatment: do not disconnect the battery until the engine has been switched off for at least five minutes. This ensures that the exhaust gas aftertreatment functions after restarting. X Ensure that: R the key is removed from the ignition lock and R all electrical consumers are switched off X Connect the positive terminals. ! Vehicles with auxiliary heating:
during heat output and the cooling-off period, the power supply should only be disconnected, in the event of danger, using the battery isolator switch. If the power supply is dis- connected during heat output, the cooling off period cannot be activated and this can damage the auxiliary heating. You will find further information in the "Auxiliary heat- ing" section. X Connect the battery cover ( Y page 307). X Connect the negative terminals. After an interruption to the power supply, e.g. reconnecting the battery, perform the follow- ing tasks: Maintenance and care X Deactivate the anti-theft protection of the CD radio ( Y page 148).
X Set the time, day and preselected heating mode of the auxiliary heating system ( Y page 102). Observe the safety notes on handling batter- ies. Checking the battery fluid level X Remove the key from the ignition lock and wait approximately five minutes. ! Check the battery fluid every six months or at least after 600 operating hours. In certain operating conditions, e.g. mowing at high outside temperatures, the battery fluid level must be checked at significantly lesser intervals. The fluid level in each battery cell must be approximately 15 mm above the top of the plate. Tap water adversely affects the perform- ance of the batteries. Add only distilled or de-ionised water.
Do not use a metal funnel for refilling. There is a risk of a short circuit. X Vehicles with auxiliary heating: ensure that the auxiliary heating is switched off and the cooling off period is complete ( Y page 104). X Switch off all electrical consumers. X All vehicles: turn battery isolator switch to position g ( Y page 90). X Remove the battery cover ( Y page 307). X Disconnect the positive terminals. X Disconnect the negative terminals.