Does anyone know the vendor that makes the Troy Built Models 16000 MAH batteries. Troy Built seems to be out of them all the time and cannot keep them in stock. I am looking for a 15000 or 16000 MAH batter for my S800 Evo around that price with the same performance. Anyone have any thoughts where to shop or similar batteries? I am trying to stay away from double packs I prefer a large single pack.