[DonRotolo]

I'm going to make a huge assumption here and guess you built a few basic robots that will be used to train drivers.

Can you run them off a wall outlet? Yes. As you almost said, what you want is a "12 volt power supply". Google it.

There are some considerations though:

1. A power supply with sufficient capacity to supply a typical FRC robot would need about 120 Amperes of current output. Such a power supply is likely to be VERY expensive.

2. You CAN put a battery into the trainer robot and also connect a power supply with a current capacity of maybe 10 to 20 Amperes. This will allow you to run a bit longer on that battery. But not forever. And not a LOT longer, maybe double or triple the battery-only time.

3. You can't leave the power supply connected to the battery if the robot won't be used for a while (more than 20-30 minutes), because it acts like a charger but isn't really set up like one - it can overcharge the battery, causing damage to many things.

4. Wires from the power supply to the robot will interfere with driving. Just like an Ethernet cord would do.

5. Running longer heats up motors more than when you give it a rest to change the battery, Be sure to manage the thermal aspects of your robot.

Another alternative is to get a larger deep-discharge type battery (sometimes called a Marine battery). It is not FRC legal, but it is a 12 volt battery and will have a far larger capacity than an FRC battery, allowing you to run quite a bit longer.

In the future, a clearer, more detailed question would help us help you better.