An easy solution for very long battery life for nex/ alpha 7/7r/7s with no power plug

hello,

I like to do time lapse in the field with my a7r and a7s and have been looking for a while for a cost effective, portable and easy solution for very long battery life. I also like to shoot videos with my a7s but have suffered of short battery life....

For time lapse, Typically my a7r would go for 300-500 shots at best and max 3 hours on a standard np50 battery. There exist power plug solutions but there is not always a plug around in the middle of the mountains or New York city...

i found some solutions on the web soldering large natteries to a power supply, but wanted an easy solutions that does not require any modifications.

if the equivalent of 23x batteries for approx. 120$ In a very portable package sounds good to you, with just plugging two cords, here is a simple solution:

Buy a power supply like this one:

http://www.amazon.com/Adapter-AC-PW20-SLT-A33L-SLT-A55V-SLT-A55VL/dp/B0083EQS3I/ref=sr_1_1?ie=UTF8&qid=1420798972&sr=8-1&keywords=Sony+nex+power+supply

Buy usb multi voltage battery like this. Other models will work as long as they deliver 9v. I bought this model and it works great. 23 0000 mAh vs 1000 for the np50 battery , in a portable, rechargeable 1lb package...

http://www.amazon.com/RAVPower®-23000mAh-Portable-External-Multi-Voltage/dp/B00HFMUBYG/ref=sr_1_10?ie=UTF8&qid=1420799170&sr=8-10&keywords=RAV4+multi+power

Voila, just connect the dummy battery to the DC output cable of the portable battery, and you have 48h of continuous power!!!!

happy shooting....

julien