Both batteries used on D800 show a 100% health. They are loaded and unloaded normally without overheating. On autonomy, no surprises, they normally take (too used to compare) I could hold a full picture day without any worries. The exterior quality is good, no particular fragility on materials. Should be on products like that have a greater return periods for defects do not always make sense to first use. For me everything is fine now.