Answer A: It will depend on the capacity in Wh (watt hours) but most commercially available ones should be OK. The IATA guidelines say that under 100Wh (multiply Ah x V to get Wh) is OK to bring on board and in cargo if installed in equipment. If they are loose spare batteries you can bring as many in carry on but not in the hold. Between 100-160Wh same applies but you are restricted to 2 spare loose batteries and again not allowed to check in. If over 160Wh you have to declare it and it has to be packed in cargo under the Dangerous Goods guidelines.Most airlines follow the IATA guidelines.
Answer B: only restriction I found was that the battery must be under 100Wh. Keep in mind that you have to validate the rules for any Airlines you will be flying and the airport rules if they are not in the US. It must be in hand luggage and not in a suitcase in the hold.
They may be found in (at least) IATA documentation and also a number of courier companies and most battery manufacturers have advice documents. Removable batteries must be carried in carry-on luggage with the exception mentioned below. Having batteries in carry=on makes sense – would you rather have a fire in a cargo hold or an overhead locker. There is an upper limit to the amount of Lithium metal that may be carried. Some manufacturers provide specific mass of Li per battery. Otherwise they have a linear conversion between Watt hour of battery (Vbat x mAh.) and Li metal.
Answer D: It’s fine in your carry on-luggage only. Batteries are not allowed in check-in luggage, only in carry on-luggage where they can be monitored. Here are the rules for batteries:
In order to ensure air transport safety, FAA,IATA, Airport has issued relevant regulations to regulate air passengers and crew members carrying power banks on to flights. The rated energy of power banks which can be carried on board is restricted and identification method for rated power has also been specified. For details, see the “Announcement of Rules for Air Passengers Carrying Power Bank onto Flights”.
Are Power Banks Are Allowed On A Flight? FAA
Summary: If you want take a power bank onto a plane you should follow below instructions of security staff during the security check. Here is the Rules in china:
“Announcement of Rules for Air Passengers Carrying Power Bank onto Flights”
1. Power bank must be carried for personal use.
2. Power bank must only be carried in hand luggage or carried around. It is not allowed to carry power banks in checked luggage.
3. If the rated power is less than 100WH, power banks can be carried without approval; power banks with the power between 100WH and 160WH can be carried after approval of air carrier. However, each passenger is only allowed to carry no more than two power banks.
4. It is not allowed to carry the power banks with power higher than 160WH or the power banks without identified rated power and with rated power unable to be worked out with the marked parameters.
5. Passengers are not allowed to use power banks to charge electronic devices during the course of the flight. Power banks must be switched “Off” during the course of the flight. Above mentioned regulations are also applicable for crew members. This announcement shall take effect from the date of its promulgation. Attachment: Calculation methods for the rated power of power banks.
Calculation methods for the rated power of power banks
If the rated power is not directly marked, the calculation methods are as follows:
1. If Nominal Voltage (V) and Nominal Capacity (Ah) are given, the rated power can be calculated as follows:
Nominal Voltage and Nominal Capacity are usually marked on power banks.
2. If only milliampere (mAh) is given, please divide the number by 1,000, and you get ampere-hour (Ah).
For example: Nominal Voltage is 3.7 and Nominal Capacity is 760mAh, and then you get the rated power:
760 mAh÷ 1000 = 0.76Ah