So any spilt fluid will not connect the terminals.
It does no harm to disconnect the battery when working on a vehicle but in general no, you do not need to disconnect them to change a filter.
Disconnect the negative cable.
If you are talking about disconnecting a battery in a vehicle, yes.
Disconnect the car battery, and reconnect it
Negative.
Disconnecting Auto Battery Terminal ConnectorsYes, it is safe to disconnect a "car" battery while it's raining, IF you do it properly.When disconnecting a vehicle battery, raining or not, ALWAYS disconnect the NEGATIVE [--] terminal first, and when reconnecting, always connect the NEGATIVE terminal last.
Disconnect the battery. Alternatively you could run a wire from the ligter of the towing vehicle to the battery of the towed vehicle.
Disconnect battery from vehicle - if this still happens battery is probably shorted internally and requires replacement
Disconnect battery for about 10 mins. or have vehicle scanned to determine problem and have code cleared
Disconnect battery for about 10 mins. or have vehicle scanned to determine problem and have code cleared
unplug the control module fuse and disconnect the battery for 5 minutes.
Disconnect - battery terminal Raise and support vehicle Disconnect wiring harness at top of starter Remove mounting bolts Remove starter