My camera purchased for the same price with another provider, incidentally, had two batteries of the type NP-FW50 inside the box. Do not know if that's in the camera offered by Amazon is also the case (in the description is only one battery) but these batteries are not so overly expensive.
The battery life is satisfactory and should be sufficient for any normal amateur photographers. However, one should not expect miracles, the camera draws a lot of power.
I use the A7S with the Sony SEL2470Z Vario Tessar T * 24-70mm F4 FE ZA OSS, E-mount zoom lens. With almost 1000 EUR not cheap but the quality is convincing. The blurred edges are not visible with my lens, it's all so crisp. The noise only starts beyond ISO 8000 correctly, to ISO 51200 are the images perfectly usable.
It is impressive, especially that the camera when focusing in dark places has almost no problems, which is amazing, and even in the dark allows very good and sharp photos.
It really is only the high price to criticize but as this camera is not essential for life but a luxury item, I draw from no stars for the price.
Incidentally, I have also bought the Sony LCS-ELCA System pocket for A7S, it protects very well but really only for transportation. As On- and Off bag you can use this bag hardly but it fits the entire camera including lens 24-70 in this bag into it. For transporting certainly the ideal (compact) solution.
Conclusion: Even if the price is painful, there is probably no camera on the market that can make such good photos in a dark environment. With the low resolution of 12 MP I can live with the lack of a flash on this camera, not the end but feature.
