I have a 2003 60 HP ELPT EFI that the alternator may not be working. I have a good battery, 100% charge. I launch for a day using a depth finder and GPS and starting three or four times, running the motor for long runs up the lake. When I come back in and hook up to a charger the battery will show maybe 80% charge. Shouldn't the motor keep the battery charged better than this? Does this motor have an alternator and if so how can I check to see if it is working properly?