January 3 2013 by
Olivia in
Battery |
eBay is having a Deal Blast for the next 4 hours (or until supplies run out) on this uNu Enerpak Tube 5000mAh USB External Battery Pack
. The Enerpak Tube boasts a 5000mAh carrying capacity which allows it to charge iPads, smartphones and small gadgets via USB port.
Specifications
Material: ABS Plastic
Capacity: 5000mAh
Input: 5V / 1A
Output: 5V / 1A (USB)
Life Cycle: >500 cycles
uNu Enerpak Tube 5000mAh USB External Battery Pack
Tags: external battery,
unu enerpak tube 5000mAh,
USB external battery pa sck
…so what is the deal price? It says 29 now, I have no idea whether that is good or not…
I didn’t need a USB battery pack, but for this price, I couldn’t pass it up. Thanks Olivia for the heads-up on these great deals!
Just so your aware… in almost all batteries of this type, the mAh rating is NOT for the actual output voltage. It is usually something like 3.7v. If you look around at what makes these battery packs you will see that almost all of the lithium ion cells are 3.7v. This is why almost all of the camera batteries you will see are right around 7.4 volts. For a Canon DSLR, there are simply 2 cells in there. For some of the big Sony batteries there are 4 they just run them in parallel.
They run them in parallel to up the amperage or mAh rating. 5000mAh at 3.7v is 18.5Wh (watt hour). 18.5/5v * .85 (dc/dc conversion efficiency) is about 3145mAh. The latest iPad has a battery 3.7v 43Wh (11560mAh) battery. This really wouldn’t charge it all that much.
I ordered one too, after seeing it is 49 on Amazon, so thanks Olivia!