# Battery (/docs/e2e/conditions/battery)



`device.battery` sets the level and charging state. On an Android emulator the app sees it; on an iOS simulator only the status bar changes (the result has `cosmetic: true` and a warning), so assert battery-driven behaviour on Android.

```ts
await device.battery({ level: 5, charging: false });
await device.battery(null); // the real battery back
```

| Option     | Takes   |
| ---------- | ------- |
| `level`    | 0-100   |
| `charging` | boolean |

The real battery comes back when the test ends. By hand with `warden ui battery`: [Battery on a simulator](/docs/sims/conditions/battery).