Whenselecting the best MagSafe power bank for your needs, keep the following factors in mind: Capacity: Numerous power bank providers state that a 5,000 mAh capacity is sufficient to keep your phone operational for more than a day. Consequently, we directed our investigation towards battery packs falling within the range of 2,000 to 5,000 5000 mAh Power Bank - Black. $44.95. ChargeUp Reserve 2nd Generation. 20,000 mAh Power Bank - Black. $119.95. ChargeUp Reserve 2nd Generation providing you with a way to charge devices regardless of your location. With many Power Banks able to charge devices multiple times over without having to access a power outlet, they are very Apessimistic reading of a power bank 20100 mAh would estimate its total power output to be. 3.7V * 20.100 Ah = 74 Wh (watt-hours) before allowing for efficiency of conversion of 3.7V to 5V (for USB) and internal conversion of 5V to the laptop battery's terminal voltage. Losses of 10% in each conversion would lower that to 60 Wh. Somedevices, like wireless headphones, have tiny batteries that take little power to charge. Other devices, like laptops, require more. You will need to perform some simple math: If the device you are TheEnergizer UE 5057 5000mAh is a small, simple power bank that’s not too expensive and which can charge two devices at the same time. But how well does it work? Does it have wireless? Can you charge this power bank and your devices at the same time? Specifications. General; Type: Small power bank: Claimed capacity: 5000mAh: Width: mAhRating Charging Capacity; 2,000-5,000: Suitable for smartphones and small devices: 5,000-10,000: Ideal for smartphones and tablets: The power bank mAh rating refers to the capacity of the power bank, indicating how much charge it can hold. A higher mAh rating means the power bank can provide more charging cycles or charge larger devices. mAh$ ratio: 697; Check price on Amazon.com. How many charges will a 30000mAh power bank provide? As previously discussed on our site, the real capacity of a power bank is smaller than its actual capacity. Roughly speaking, you’ll get about 75% of the listed capacity. So a 30000mAh power bank will provide an actual charge of around For5,000 mAh generally means you can expect to get 100 mA for about 50 hours usage, or 10 mA for 500 hours, or 1 mA for 5,000 hours. How much can a 20000mAh charge? With a 20,000mAh power bank (actual capacity: 13,300mAh), you can charge tablets and laptops about 1.5 times. dNdx.