Bests & Worsts Reviews from Amazon

Recently I purchased three very similar products just for testing. They are: - MoKo [Fit-Charge] 9000mAh Portable External Battery Charger (this product) - SUNYEE (Lifeform) 8400mAh power bank, and - RAVPower 8400mAh power bank Externally, all three products look nearly identical (see the product picture I uploaded). They all come with dual USB ports, a 4-segment battery status indicator, a small LED passing as flashlight, etc. They have nearly identical dimensions and similar weights. According to my electronic kitchen scale: RavPower unit = 182g; Lifeform = 189g; MOKO = 197g Internally, however, they are quite different. The Moko unit is definitely the best based on my testing. [Output Current] The Moko unit comes with two identical USB ports. I can recharge my B&N NOOK HD+ Tablet at full speed (1.95A) from either port. The maximum total output current is around 3.2A, according to my load test. The other two power banks both have two ports labeled `1A' and `2A' respectively. But I can only charge my Nook at 1A from the first port, 0.45A from the second. Their total output current are both limited to just around 2A. [Output Energy] In my battery capacity test, the Moko unit is able to sustain 1.9A at about 5.1V for 181 minutes. This corresponds to a total output energy higher than that by other two units: - Lifeform: 25Wh - RavPower: 26Wh - Moko: 29.5Wh [Battery Status Indicator] None of the products' status indicators are completely linear. That means you cannot interpret one LED out of four as 25% capacity. But the Moko unit comes closest: 4-LED: 80 to 100% 3-LED: 65 to 79% 2-LED: 40 to 65% 1-LED: 3 to 39% Blinking: under 2% [Accessories] Here the Moko unit comes up short. There is just one short USB cable in the box. No adapters, pouches, etc. [Bottom Line] Electrically, the Moko unit offers the best performance in every category I tested. Price-wise, the Moko unit is currently positioned right in the middle between Lifeform (highest) and RavPower (lowest). So I definitely recommend getting this Moko product over the other two brands. [Update on Aug 31, 2015] I should mention that the Moko unit supports pass-thru charging. That means it can continue to power USB devices even while its internal battery is being recharged. This feature is not available on most higher-capacity power banks such as the AmazonBasics PB10. [Update on Oct 18, 2015] I have been using the Moko unit in my car as a 'buffer charger'. It serves the purpose perfectly because: 1. It allows pass-thru charging of two USB devices from one USB port in the car 2. It starts charging automatically whenever an USB device is connected 3. It enables my GPS unit to function without interruption even when the car's engine is off 4. It can be used as an emergency flashlight if needed. [Update on Mar 13, 2016] Uploaded a picture showing some of my favorite power banks of various capacities: AmazonBasics 10,000mAh, MoKo 9000mAh, KMAX-812 4400mAh, and TYLT 3200mAh.