I just picked up a ext efi 580 deluxe. When I start it it runs great for like 15 minutes then it wont rev out. when i put the battery charger on it it starts right up. I checked the voltage at the battery and it bounces from 5 to 7 volts, but when i rev it up the light gets brighter and the voltage in the battery stays the same. I checked all the fuses and grounds and their all good. Then i let it set over night and the battery reads 12.5 volts. If anybody has any ideas on whats going let be know, cause i just got some snow.