The best way to check whether the Oral-B Vitality brush is charging is to pick the toothbrush up off the charger after 30 minutes and switch it on. If it comes to life, you know it's charging. Switch it back off and leave it on the charging stand for the full 16 hours it needs to complete a full charge.
With these toothbrushes it's important to know that they need to be turned off in order to accept a charge. As there is no indicator light to let you know and only one button for both the on/off position, sometimes it can be tricky. If your toothbrush runs flat/dies while brushing your teeth, please make sure that you press the on/off button to switch it off. Even though there's no power, if you don't press that button it will remain turn "on" and therefore won't accept a charge when placed on the charging base.
If you pick your brush up after 30 minutes to check, push the on/off button and nothing happens, it was likely in the "on" position while it was sitting on the charger and therefore did not charge. Do not press the button again, place the brush back on the charger, then try again in 30 minutes.