ATROCIOUS.

Singular "bitcoin" for the whole unit. "bitcoins" is Boomer shit no matter which level of denomination we're talking about.

Plural "sats" for the fractional unit. It just sounds cool. 

 bitcoins is fine, don’t be a zoomer. 

 "It's raining, there's waters on my window."

"Ah, I love hiking, breathe in those fresh airs!"

"Ug, the beach, I have sands in my shoes." 

 that must have broken you, to write those three sentences 

 It’s a countable noun. 

https://bitcoin.stackexchange.com/questions/1469/is-bitcoin-a-countable-noun