if you had to brighten up a patio with only battery-powered lights...

Hypothetically, say you're stuck with a patio space that has zero outdoor outlets (ugh, I know, who designed this?), and your only option is battery-powered lighting. What would you do? I'm thinking fairy lights or those LED lantern things, but battery life worries me a bit. Anyone tried something creative or found a setup that actually lasts more than one evening?