That would depend on the connector being used for your specific vehicle.
Some can use alligator clip leads with T pins, other can use straight DVOM probes.
As to power …
A wiring diagram is quite helpful to determine voltage used or use a DVOM to measure power at the connector.
Many commonly use 12VDC, but best to confirm for your vehicle in order not to cause damage.
Once the voltage is confirmed any battery with the same voltage will do.