Yeah. Unlimited Chakra and Stamina.
Why do you think Itachi was able to keep up Susanoo without dying 3 minutes later?
I believe all reanimated people chakra works in the same way. They don't have more chakra than they did when they were alive. Their bodies just instantly regenerates any chakra they use. Similar to how their bodies instantly heals any injuries.
Madara didn't need to use the Juubi then since he had more chakra than it