My 150 hp mercury died on me in the middle of the lake. My GPS would not come on my radio would not come on. I let it sit and it finally started and ran long enough to get me to the launch. I replaced the batterymy GPS came on and the voltage was reading 9.1 when I cranked it. I ran it a few minutes and it died again and I waited a while and it cranked and ran for a few minutes. It is not charging the battery. Is it the stator that is out or is their other things that can cause this. Thanks