The battery lasts up to five hours when printing continuously and several days up to a week when used occasionally. You can check the exact values on the e-mark connect page in the app.
The battery needs to be charged for approximately 3 hours to reach 100 %. Nevertheless, you can also charge your e-mark (which should always remain in the docking station) whilst using.
Note: Do not charge the battery longer than needed in order to protect the battery and ensure a good print quality.