My new SP3 has had extensive travel use over past couple weeks and have to say I'm disappointed in the battery life. So I'm looking at picking up external battery.

Any experience or advice would be appreciated, as my knowledge lies elsewhere

I know I have to have buy the SP3 adapter cable and am looking at this one:
http://www.amazon.com/dp/B00PQUCE9O/...ing=UTF8&psc=1

My primary consideration for the external battery is weight and size, as long as it can charge the SP3 one time, while I am using it, and can also charge my Samsung S4. Also, of course, a reliable product line.

These are the three I'm looking at. The RAV and Power Castle apparently both weigh about 1.47 pounds, at 7.3 x 4.9 x 0.8 inches. I couldn't find specs for Qi

http://www.amazon.com/gp/product/B00...A3DNJ55ZGSMH7I

http://www.amazon.com/gp/product/B00...A2KUZVNQ9LP7N9

http://www.amazon.com/gp/product/B00...A2KV19AYUKS3X0

Thanks,
Doris