Built-in Lithium Battery,it can use for 60 minutes continuously when you recharge 3-4 hours fully recharge. Portable handheld mini usb vacuum,stronger suction,the vacuum cleaner is in a small size (5.9 x 6.1x2.6 inch,230G),enables you to take it anywhere you want to clean It can be recharged from any USB port or computer,no external power source required;It will be more powerful if you connect it directly to 5V 2A charge than laptop or power bank.Don't worry about the voltage.It is very convenient and energy-saving Normal maintenance:Open the dust pot and take the filter mesh out, then wash it with clean water,you can continue to use it after it is dry. 2 Vacuum Nozzles:2 Different vacuum nozzles allow you to reach the tightest spaces;Flat nozzle can inhale little pieces of paper while brush nozzle can dry ash and dust.