Get Sony A7R II at B&H Photo.
The 42-megapixel Sony A7R II ships with two batteries and an AC charger. Yay!
Sony Alpha a7RII Mirrorless Digital Camera (Body Only)
• 2 x NP-FW50 Lithium-Ion Rechargeable Battery (1020mAh)
• AC-UUD11 AC Battery Charging Adaptor
• BC-VW1 AC Charger for W Series Battery
• Shoulder Strap
• ALC-B1EM Body Cap for NEX Cameras
• Multi Interface Shoe Cap
• Eyepiece Cup
• Micro-USB Cable
• Limited 1-Year Warranty
But what a minute, why does it ship with two batteries? Perhaps the battery life is very poor, just like with the Sigma dp Quattro series; bowing to reality Sigma includes two batteries, which I applaud.
What I do not recall is whether the battery can be charged in the camera via a USB cable as with the Sony RX100. If so, then the relatively compact 60 watt-hour BatteryBox could be tossed into a daypack for field outings (day or days long) to recharge batteries on the fly. Since the BatteryBox is 60 watt-hours and the Sony battery is only about 7 watt-hours, it would provide about 8 battery recharges for Sony batteries, assuming high efficiency.
Tero N writes:
All A7-series cameras even prior to A7R II can be charged on the go from Micro-USB power pack, but camera needs to be turned off.
A7R II is actually improved in this context; it can run purely from external USB power if there is a non-empty battery inside. A nice addition, I'm gonna velcro a 12000 mAh battery pack to my tripod extra juice for long-exposure stuff. You can find details in the manual that is available for example below.
DIGLLOYD: excellent. With an AC charger (what I really use) plus a USB option (plugs right into the Wagan Tech power inverter or the BatteryBox, charging options are good. The Battery Box can be used in the field and the USB option in the car, freeing up an AC outlet on the inverter.
Eric W writes:
There are also a number of dummy battery cables available for the a7 series. They are usually terminated in the anton-bauer d-tap plug. I use the DionicHC batteries with my a7s and they can run it for 6-8 hours of recording.
I had suggested to someone on a forum that needed to run the camera in extreme cold, to use this cable, paired with an extension cable run up the sleeve to a battery kept in an inside vest or pocket near body heat. The anton bauer batteries are quite large, another option I like is from SWIT:
It is an 86wh battery with a 14.4v output and a 5v USB output. This would be easier to fit in a pocket or inside a jacket than the larger AB batteries.
DIGLLOYD: nice option.