Dead battery. can i take it off charge after 30 mins and then charge it by driving it?

It won't charge well that way. The alternator is designed to replace "as used" and to maintain a charged battery. It's not really designed to recharge a dead battery. It's better for the battery and the alternator to charge the battery fully prior to reinstalling it.

Depends on the status of the battery, after it has been charged for 30 minutes, and how much charge was going into it during the 30 minutes.

If it was dead, wouldn't turn on lights or anything, you will need to charge it up for a few hours, and get it up to around 12 volts on the charger, or where it shows "charged" ..

New cars with computers, need at least 11.5 volts, and if you have barely that then when you start your car, the starter might take a lot of that and your car might not run.

Also.... Alternators are not designed to be chargers, only to be used to "maintain" charge. Putting to much of a load on the alternator could damage it.

So, bring the battery up to full charge, on the meter, and if you have a voltmeter, check the voltage. When it is up to 12 volts or more, you can use it.

You should probably take it up to full charge,(no cables hooked up), check the voltage immediately, and then, let it set for half an hour.... if the voltage drops a lot during that time sitting disconnected, your battery is shot.

Agree with Mustang.

Unless it is an emergency - NEVER charge a dead, or moderately discharged, battery with the vehicle charging system. It can be damaged!

When charging a battery with a portable charger - charge it on a fast rate,(6-8-10-12 amps) not a slow rate unless it is a small battery, (mower - motor cycle etc).

Not sure if 30 mins is long enough, what kind of charger are you using.

What caused the battery to die in the first place.

But if it starts the car and the alternator is good then yeah, it'll work.

mustanger is correct but as I said, if it starts the car then it has enough juice.

I have killed a lot of batteries in my life time and would often just get jumper cables and start my car with someone elses.

That is with a dead battery being charged as I drive around!

yes you can its a good idea to give it a slow full charge, but if you are in a hurry you can disconnect the cables and to to town.

Sure. Why not.