More C-pap questions

Hubby and I both use c-pap. I can sleep without it (I take it off in my sleep) He, however can’t.
He’s worried about power failures. Does anyone know if there is a battery back-up available?

(We’ve had only one power outage in 15 years at our present residence)

About battery back up.

Battery packs.

Thanks Pat! That’s perfect.