Dolby Dimension charges quickly when you use the original Dolby USB that is shipped along with the headset. The capacity of the USB chargers shipped with Dolby Dimension is 7.5 Volts and supports the feature of Fast Charging. Fast Charging is the feature wherein Dolby Dimension will automatically charge up quickly within the first 15 minutes of charging. In 15 minutes, you will get the battery charged for over two hours, the length of a typical movie.
Check if you are using the USB shipped with Dolby Dimension. If not & you are using some other USB from the market then charging could be slower than expected. We recommend you to use only the original Dolby Dimension USB