I'm going somewhere cold soon, I've not used the E-M1 in such conditions, yet (-10, -20C). However I've used a Canon dslr, and I was swapping around 3 batteries per day, not cool. I couldn't find Olympus OM-D specific off the shelf solutions so, I'm thinking, what if I do something like that http://radom.city/index.php?n=Foto.Zasilacz (photos are self explanatory, I don't speak Polish either), but instead plug it in an external battery pack in my backpack? Essentially creating somethong like that Switronic Powerbase 70 Perhaps using a neoprene insulated coiled cable for convenience? Not too dissimilar to http://static.bhphoto.com/images/images500x500/862010.jpg Anyone tried something similar? What battery packs would be potential options? What are the potential dangers of damaging the camera, it can't be as simple as matching the oem battery specs to the external pack.