Board Thread:Theories and Speculation/@comment-25139119-20150807165411/@comment-6769189-20150807184442

Naruto doesn't need all their chakra to communicate because Kurama has the ability to speak with them in his subconscious and Naruto can enter that place.

Tailed Beast chakra isn't self regenerating. Never was.

There is no proof that Naruto has the rest of their chakra on hand constantly. He may have borrowed enough to undo the Infinite Tsukuyomi after he emptied his reserves against Sasuke. All the Tailed Beasts were also present at the time so he may have siphoned it from them at that time, not actually storing it within himself.

He may also just have a very small amount that he doesn't use for battle, but he would have had to get that after The Last.

Kinkaku and Ginkaku seem to be a different case. They lived and survived for 2 weeks off Kuramas flesh and chakra. They seemed to have integrated it with themselves.