Seat Exeo 2012 Owner's Manual page 236

234 Checking and refilling levels
A flat battery can freeze at temperatures of around 0 °C. The battery must be
defrosted before charging ⇒
frozen, because the ice can crack the battery casing and allow the battery
acid to escape.
The battery caps should not be opened while the battery is being charged.
WARNING
Never charge a frozen battery. Failure to comply could result in an explo-
sion.
. It is advisable to replace the battery if it has
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