Bests & Worsts Reviews from Amazon

The Anker PowerCore Fusion is a combination 2 USB port wall charger and Li-ion battery bank rated at 5000mAh and 3.7V, giving a paper spec of 18.5Wh capacity. I used a DROK variable voltage load tester, which can apply a constant power draw to a USB power bank like this Anker. I measured 15.4Wh draw before my Anker Fusion shut down. Assuming the paper spec of 18.5Wh, that is about 83% efficiency. There is an inherent 5% "loss" since the Anker is designed to shut down with 5% capacity remaining. So the available capacity is actually about 17.6Wh (95% of 18.5Wh), giving an efficiency of about 88% for the conversion of the battery bank power into 5V USB. That seems like good performance. I ran my DROK test at 5V/2.5A to give me the measured 15.4Wh power draw (17.6Wh - 15.4Wh = 2.2Wh presumably lost as waste heat -- the Anker did get warm). Because of the Peukert effect, it might be that at lower current draws, the efficiency is a little better than 88%. I also tested the available amps out the USB ports when the Anker is plugged into AC, an well as when it is unplugged and verified the manufacturer's specs. When plugged into AC, I verified the product spec using the DROK tester and measured 2.35A out at a nominal 5V. The manufacturer's spec is 2.1A. The Anker quickly "fell off the cliff" at current draws above 2.35V, with the voltage dropping rapidly before the Anker shut down completely. When I loaded both USB ports, I also verified that the Anker delivers a total of 2.35A to both USB ports. On one port, I had my DROK tester. On another port, I had my PortaPow USB monitor with a cell phone plugged into the monitor for recharging. The cell phone was pulling 1.2A during this test while recharging. When I cranked up the DROK current draw past about 1.1A, the cell phone started to get less current, to keep the total current draw at about 2.35A. One strange behavior noted -- if I cranked down the DROK current again to below 1.1A, the cell phone DID NOT return to its original current draw of 1.2A. It stayed "stuck" at whatever current draw it was at when I started reducing the DROK current draw. I don't know if this is the fault of the phone's charge controller or the fault of the Anker. But basically, it looks like if you are charging your phone and then decide you also want to charge an iPad or similar high-draw item, your cell phone could get shortchanged and charge slower than expected even after removing the iPad. Unplugging my cell phone and plugging it back in again seemed to reset the charging current back to the expected 1.2A. When unplugged from AC, the Anker delivered 3.2A at a nominal 5V. Again, the Anker fell off the cliff rapidly when I cranked up the DROK past 3.2A. And similar to the plugged-in case, the Anker delivered a total of about 3.2A when both USB ports were loaded (again, DROK on one port, cell phone on the other). I also saw the same odd behavior with my cell phone current draw when I cranked up and then cranked back down the DROK current draw. I also checked the accuracy of the LED power display and the lights seemed to be right on when indicating the remaining battery capacity. As I drained the Anker (DROK tester again set at 5V/2.5A load), I got two LEDs right at about 2/3 remaining capacity, one LED at 1/3, and a flashing LED at about 10% remaining. Finally, I tested the behavior of the Anker LED display when being recharged (either via AC or via the micro-USB input) and then plugging in a device into a USB port to recharge or power that device. As the product manual says, the Anker can't recharge itself at the same time it recharges or powers something that is plugged into one of the USB ports. However, the Anker's behavior is not always consistent with the product description. When I charge the Anker either via AC or micro-USB, the LED display behaves correctly. It shows some solid LEDs to indicate the state of charge, and a flashing LED to show that the Anker is recharging. So far, so good. The Anker web site FAQ for the PowerCore Fusion 5000 then says "When PowerCore Fusion 5000 is charging your device as a wall adapter, the LED power meter will keep on in a circle from the first to the last. When PowerCore Fusion is charging your device as a portable charger(not plugged into the mains plug), the LED power meter will stay on, displaying the battery’s remaining power. The light will fade when the device is fully charged and no longer drawing a current." So with the Anker plugged into AC, I plugged in a USB cable to charge my cell phone. Sure enough, the LED display on the Anker changes from showing the battery state to the LEDs lighting "in a circle from the first to the last" (i.e., sequentially). With the Anker recharged through the micro-USB, I again got the expected change in how the LED meter indicates the mode of the Anker. However, when I used my DROK as the USB load instead of my cell phone, then the LED meter did not behave correctly. The blue LEDs continued to show the Anker battery state of charge until I dialed the DROK up to about 0.7A draw. Then the LEDs changed to the "circle from first to last". This was the case whether the Anker was plugged into AC or into micro-USB and whether the DROK was in one USB port or the other. I'm thus dinging the Anker one star for the two unusual behaviors noted above when running both USB ports at the same time, and when the Anker is either plugged into AC or into micro-USB and a device is simultaneously running on a USB port. August 2021 update: At some point, the PowerCore Fusion 5000's internal battery stopped being able to get recharged. When nothing is plugged into the PowerCore Fusion's USB ports, the Fusion should start to charge its internal battery. My Fusion looks like it is charging the internal battery (the first LED light starts blinking), but the battery charge never gets past the first LED. And if I do have something like a cell phone connected for recharging and unplug the Fusion from the wall outlet, the Fusion does not continue to charge the cell phone, presumably because the internal battery has no charge. So basically, I have a plain two USB-port charger. IMO, that is poor battery life, not being able to hold a charge after only 3 years (or less - who knows when the Fusion actually crapped out).