According to the FAA, you can have any number of Lithium Ion batteries below 101 Watt hours and 2 for anything rated higher than that & must get airline approval.¹ Per the TSA, you can't have any batteries over 100 Watt hours in your checked baggage.² Are you unsure whether you'll be able to take your portable battery pack on your next vacation We have to perfect tool! Our calculator will determine whether you can take your battery on a plane or if you'll have to leave it behind. Simply enter in the mAh, or milliamp hours, of the device and the nominal voltage in the required fields and the calculator will do the rest!