Is there a way to test batteris with the dc power supply

jose ontiveros, there is really no good way test a battery with a multimeter. Just because a battery would show the proper voltage, does not mean it will hold a charge. The open (unloaded) voltage of a battery as measured by just using a voltmeter is almost meaningless. Even a dead Battery will often read some kind of voltage. You would have to test it under a load, for that you would have to add enough resistors to it to simulate a load.

You do want to check your charger to make sure it is working, and you can check the voltage to the battery connector coming from the charger. The left and right outer contacts are the positive (right) and negative (left) see what voltage you get with your iPad plugged in to the charger. Remember that your battery is a smart battery. It does more than just store energy, it also provides feedback to your OS etc. it also requires a minimum voltage to be charged. Once it is below that particular threshold it will not charge, but still show voltage (around 2.8) when measured with a multimeter.