I put one of these through a full performance and capacity test. First, the good news. It is properly rated as an 8000 mAh power bank. After fully charging it, I placed a continuous 1 Amp load connected to Port 2 (the 2 Amp port) and monitored total charge delivery until it shutdown due to battery exhaustion. It delivered 5375 mAhr of charge near the USB spec of 5 volts. (The 8000 mAh rating is for the Li-Ion battery, which provides 3.7 volts. The internal voltage conversion circuitry steps the voltage up to 5 volts, which reduces the actual charge delivered.). For an 8000 mAhr Li-ion battery, a USB 5 volt charge delivery of 5300 or higher indicates a properly rated battery.
Now the bad news... This device is described as being capable of providing the "Fastest possible charge time for your iPhone®, iPhone 6 Plus, iPad®, or Android™ devices." And having "Two dedicated ports to charge two devices at full speed." The two ports are rated at 2 Amps (for tablets) and 1 Amp (for phones), and in order to charge two devices at full speed simultaneously, the total output between the two ports needs to be 3 Amps. Unfortunately, this device can only sustain a current delivery of 2.51 Amps, 0.5 amps below rating. Any attempt to draw more than 2.51 Amps total for the two ports results in the unit shutting down due to surpassing the current capability of the power conversion electronics.
I have tested the 6000 mAhr, 8000 mAhr, and 10,000 mAhr versions of this device and the ALL suffer from being over-rated in this regard. A hardware redesign or a down rating of the specifications is required for these devices.
During a recent power outage we were able too stay informed by using this product to keep our phones charged. Also, gave one to a neighbor who kept her family’s devices charged. The light was very helpful
I got this battery due to its low price point for what I was planning on using it for (powering some custom made USB fans). Compared to other Monoprice batteries I have owned and used, this battery feels very cheap.
I also ordered one of the 2000mAh units, and was surprised when the smaller, cheaper unit came with a USB cable, and this one didn't, even though it indicates one is included.
The battery charge indicator on the top is worthless. There is too much bleed over from the other battery gauge LEDs that it is impossible to tell if it is showing a full charge (4 LEDs), or a low charge (one LED)..
Overall, for what I plan on using it for, it seems to be OK. If the battery gauge worked better, I'd give it at least 3 stars.
This pack is just what I needed. My wife keeps it in her purse so the little one has killed his phone battery on car trips it is much easier to plug it into the pack then stringing USB cord from the dashboard to the backseat. Charges his LG G3 from zero to full in about an hour. Much recommend Ed!