Yup, that one.

Should I buy extra batteries? Cant find them on BG.

No need as the battery of H7 is soldered to its main circuit, so its useless buying extra batteries. The flight time is 6+ minutes, that's pretty good for a Nano Quad. As its a new Quad, Spare batteries are not yet available on BG. Don't worry, they'll be available soon.

I have planned to remove the soldered battery and connect a JST connector to allow replaceable batteries. Will let you know if i carry on with this modification, until then, enjoy the 6+ minutes you'll get off of it.