I too have a 4G mifi and I love it! The data speeds are unbelievable fast! May I ask what make and model mifi device do you have? When the mifi is not in use then I recommend powering the device off, as this will save battery life. Keep in mind that while the device is on, it is transmitting a 4G wifi signal even when not connected.
All of our 4G mifi devices have a default password on a sticker at the bottom of the device. If you would like to change you mifi password then this process can be done on the admin page. Below are the steps on how to change the mifi password.
These steps may vary from device to device, which is why your response is needed to ensure that you are able to change the password properly. If you have any additional questions or concerns then feel free to reply to this posting.
Follow us on Twitter @vzwsupport