Poweradd™ Ultra Slim 2600mAh with Flashlight Portable Charger External Battery Pack Power Bank for iPhone 5S, 5C, 5, 4S, 4, iPod (Apple Adapters Not Included), Samsung Galaxy S4, S3, S2, Note 2, Note 3, HTC One, Most Android Smart Phones and More Other USB-Charged Devices (white-green)..
Buy Poweradd™ Ultra Slim 2600mAh with Flashlight Portable Charger External Battery Pack Power Bank for iPhone 5S, 5C, 5, 4S, 4, iPod (Apple Adapters Not Included), Samsung Galaxy S4, S3, S2, Note 2, Note 3, HTC One, Most Android Smart Phones and More Other USB-Charged Devices (white-green) By Poweradd™
Most helpful customer reviews
66 of 69 people found the following review helpful.
Performs just as advertised. Detachable LED flashlight is a bonus
By NLee the Engineer
Prior to the purchase of this PowerAdd 2600mAh Power Bank, I already have several similar products, such as the Black Lip Gloss 2200mAh Universal Mobile USB Portable Power Bank. The main attraction of this PowerAdd unit is that: it comes with a detachable LED flashlight module. That means for the same price, I get to have a flashlight for 'free'. Better yet, in case of emergency, I can even attach this LED module to my other USB power bank unit, and get another LED flashlight instantly!
As a USB backup power bank, this PowerAdd unit works exactly as advertised. It can produce a 5V output at up to 1A, and its battery capacity is estimated to be around 2600mAh. Here is how I estimated its capacity:
I used this fully charged PowerAdd unit to recharge my D2-721 7-inch tablet, which has a 3000mAh internal battery pack. The starting battery status of my tablet was 26%. I let it charged for nearly 4 hour, during which I only power up the tablet once every 15 minutes to check the progress. The final battery status reached was 96%, which means it replenished 70% of the tablet's battery pack, or 2100mAh.
But why does this PowerAdd '2600mAh' power back only recharge my tablet's battery pack by 2100mAh? This is because the charging process involves two power conversion stages: First, the PowerAdd unit's internal 3.7V battery has to be boosted to 5V at the USB port. Next, the 5V at USB port is down-converted to recharge the tablet's internal 3.7V battery. Even if each conversion is 90% efficient, you still lose 20% energy in the process. 80% of 2600mAh comes to 2080mAh.
The PowerAdd unit has only one Red/Green LED status indicator, but it conveys a lot of information:
- During charging, the LED blinks Red. It stays solid Red after charging is done.
- During discharging, the LED stays Green initially.
- When the battery is less than half full, the Green LED blinks at once per second.
- The Green LED goes off when the battery is completely out.
One minor concern I have is that: it takes a very long time to recharge this power bank through micro-USB port. The charging current is supposed to be 1A, so I expect it to take just 2.5 - 3 hours to fully recharge the internal 2600mAh battery. In real life, it took around 5 hours before the Red LED stopped blinking.
Overall, I consider this PowerAdd power bank charger unit a good value (4-star). Added one more star for the detachable flashlight unit.
[Update on Oct 8, 2013]
I measured the runtime of the LED flashlight to be around 9 hours 45 minutes. Its power consumption is therefore estimated at 0.75W, based on my energy calculation.
28 of 32 people found the following review helpful.Saving my life, one gadget at a time
By Erin
This is the best thing I have ever seen. It charges my phone faster than plugging it into the wall. I charged it during lunch one day. Started out at 30%. When I checked it after, it was at 70%. How awesome! This thing is a MUST HAVE!!!
10 of 11 people found the following review helpful.works great!
By Aspuckett
bought this for long airline flights and it works great! the only thing is that you have to have additional cords but i usually have them on my anyway. great buy.
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