Matt Pluckrose of Desktop Ideas on 10 things you need to know about power banks.
1) A power bank is a battery to charge your gadgets and electronic devices. They are generally rated in their battery capacity (milliampere-hour or mAh), in their output capacity 0.5-1A (smartphones only) or 2.1-3A (smartphones and tablets) and by the speed at which they charge input voltage/mAh and output voltage/mAh – the higher the input rating, the quicker it will re-charge your device.
2) The speed at which the power bank charges your device is unaffected by whether it’s a 2A model or 1A model, assuming it’s fit for purpose.
3) An average smartphone has a battery of around 1400-2900 mAh whereas a tablet or iPad has a battery around 8000-12000 mAh so it’s important to choose a power bank for the job intended: a basic 1000-2000 mAh model won’t be much good for a tablet re-charge.
4) The stated capacity (mAh) of a power bank will never be the actual power delivered. Expect to get about 80% to 90% of that claimed by the manufacturer. Similar to flash drives, some of the capacity is lost in heat and voltage conversion.
5) The battery size (number of cells) of the power bank is directly proportionate to its weight and size. The bigger the battery, often the heavier (less portable) it will be.
6) Power banks are generally powered by Lithium batteries (Li-polymer or Li-ion) and are classed as dangerous goods by airlines. Check carefully with your supplier if they are being exported to a conference, etc as they must be packed and certified ready to fly.
7) Power banks can be very dangerous if made badly. Note EE’s near disaster when 500,000 had to be recalled due to overheating. Always check with your supplier that they have and can, on demand, show you MSDS certificates (UN 38.3) and SDS (Safety Data Sheets).
8) Power banks are currently the fastest and best-selling gadget on the market and look likely to stay that way. They vary in price from around £2 to £100 each, which often is linked to battery size. The cheapest is around 1000-2000 mAh and the largest over 20,000 mAH.
9) Good-quality power banks will have a CPU inside to prevent overcharging, over-discharging and short circuits. Some even have a secondary “smart chip” to act as a secondary guard against the above.
10) The next generation of portable power will feature items such as speakers and torches that serve two purposes one to recharge and the other a secondary purpose.