You probably have a failing alternator.
Unhook the car battery.
No.
No, you can charge it in the car fully connected.
Why do you want to unhook your battery??? If the alternator is good the car will continue to run, if it dies then you have a bad alternator this is why you would want to unhook the battery cable to check and see if you have a bad alternator
disconnect the negative (black) first then positive (red).
Pull the radio out and cut the little red wire going into the radio.Make sure battery is disconnected when you reconnect battery car will start.
You can either pull the fuse or unhook the car battery.
Just hook up the charger to the battery while it is still in the car and do not unhook it.
its mounted on the transaxle under the car
to cool the coolant in the engine
With a scan tool, or unhook the battery for five minutes.
You just unhook it remove and put the new one in.