1. A power bank is a battery for charging phones & electronic devices. They are rated in their capacity shown as mAh [millampere hour], their output capacity and by the speed at which they charge. The higher the input rating the faster it will re-charge the device.
2. A 2A or a 1A model has the same speed of re-charging.
3. It is important to chose the right power bank for the job intended. Basic models of 2000 mAh or less will not work with tablets.
4. The actual power available will always be 80-90% of the stated capacity because of heat loss & voltage conversion losses.
5. The battery size will determine the weight of the power bank. Larger ones for tablets can be quite heavy.
6. As they usually have Lithium batteries they are classified as dangerous goods by airlines. If being sent by air to a meeting, exhibition and so on, it pays to check with the airline in advance.
7. Safety. Poor quality power banks can overheat and be dangerous. Always ensure that MSDS certification is available, along with Safety Data Sheets [SDS].
8. There are many models available and the price is decreasing all the time. Do not be tempted by a low capacity model which may frustrate the user.
9. Check to see if it has a CPU installed to prevent over-charging and over discharging which will limit the life of the power bank.
10. The next models are planned to have extra features such as torches & speakers to give them extra uses.