Nohasslekindaguy
Well-known member
I have a 1989 25hp Evinrude. These motors do not use a voltage regulator on the charging system. According to the manual, you should only use a non-maintenance free battery, the old kind that you fill yourself. Supposedly, this type of battery acts as a sort of regulator, and a maintenance free battery does not. I am having trouble finding one of these batteries. I'm using a maintenance free battery and during high rpm operation, voltage reaches 16 or higher. Is there any way to convert the charging system to a regulated system? Anyone have a shortened battery life by using the newer type batteries with this system? Thanks for any help.