Westfalia BX-1(FI) Instruction Manual page 12

Safety Notes for Lead Acid Batteries
 All batteries loose their charge after some time if temperature
increases. Self-discharging of maintenance-free batteries is lower
than discharging of common lead-acid batteries.
 Preferably store batteries in cool temperatures to avoid self-
discharging to a minimum.
 A battery that has been stored uncharged for long period of time
will "sulphurize" very easily and looses its capacity because
sulphur will deposit on the plates.
 A fully charged and fault-free battery has a no-load voltage of
12.7 V or more. A defective or discharged battery has a no-load
voltage of 10.5 V or less.
 Be sure the area around battery is well ventilated before and
while charging process. If not possible it might be necessary to
take out the battery from the vehicle for charging. Always turn off
all accessories in the vehicle and remove ground cable from the
frame.
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