Last week I received a Phoibos Eagle Ray, which has a miyota 9015 movement. It appears to have some power reserve issues. I first noticed it within the first day of having it. I had given it a few hand cranks to get it going and then after sitting around relaxing, I looked down and noticed it had stopped. No big deal I thought, I just only given it a few cranks and hadn't really moved. On Saturday someone asked me what time it was and I was about 45 minutes behind, unbeknownst to me. I wasn't sure if this was a power issues or if it was losing time that badly, because I had never noticed it not running. I did a time study on it and over the course of two days it lost about 3 seconds. During this time I had made a point of winding it a few times throughout each day to make sure it kept going as I wasn't wearing it the entire time. I had worn it from about yesterday afternoon at 4:00 PM until about 10:00 PM.
It was still running this morning. I gave it a solid 20+ cranks until I could feel the tiny bit of periodic spring telling me it was fully wound. I work a desk job, but I still move about a good bit. I've never had an issue with any of my other automatics stopping, including my Orient sun and moon which doesn't have any hand wind option. At about 3:15 I looked down and noticed that it had once again stopped, and had been for about 40 minutes. When I took it off I gave it a few side to side motions to get it going again followed by 40+ hand cranks. It's clear that I'm going to have to do a full time study to see how long it's lasting, but I have to imagine something is wrong. I have never had an auto stop working while on my wrist, especially after I had been wearing it for hours and had given it some cranks not even 8 hours earlier. The only possible thing I could think of is that because the movement is unidirectional that it won't charge as easy as some of my others, but that still doesn't explain the loss of power when I had hand wound it. Any thoughts on the issue before I prep to go down the warranty path? I have continued to do time studies and it has continued to keep time without issue, it's just had multiple occurrences of unexplained stops at this point. I don't have a winder and am finally debating getting one, but that still doesn't explain why it would lose all power on my wrist after all of the hand winding.