We're on 10 acres, and there isn't a good way to get power all the way out to the chicken pen. Has anyone tried to make a cookie tin heater with something like this? It's a portable, rechargeable, battery powered hand warmer. I wonder if it might have enough warmth to keep water from freezing. We're in NC, so it doesn't get crazy cold, but it definitely gets cold enough to freeze water over night in winter.
http://www.amazon.com/gp/product/B002U36EPK?ref_=cm_cd_al_qh_dp_t
http://www.amazon.com/gp/product/B002U36EPK?ref_=cm_cd_al_qh_dp_t