Don't get me wrong, there is plenty of power in the battery and it starts 100%, it was just an observation that if you measure the battery under load the a.p.h. rating is lower in the frosty weather and I am sure that everyones is like it as it is a natural occurance. It was my curiosity with electronics that made me want to check it. I do have an optimate 3 connected, it was all the kept the last battery going.