Older motor & Maintenance Free batteries

[joeyd50]

A guy is working on a friends motor, a 2000, 225 HP Johnson, He said a older motor and maintenance free, the stater does not know when to stop charging. Does that sound right

 

[Grub54891]

Well, a maintainence free battery does wear out. If it's overcharging, it could be a bad battery, or a voltage regulater issue.

 

[flyingscott]

Pretty sure that v6 has the regulator/rectifier on it so no that would not be right. The older motors with the unregulated charging system (just a rectifier) cannot use maintenance free battery. That system will overcharge a battery and boil the electrolyte out so it needs to be filled regularly.

 

[jimmbo]

Maintenance Free batteries and unregulated charging systems are not good matches. The battery being sealed has no way of Adding water to replace what gases off if overcharged. Being that unregulated systems have a low charging capacity, an engine that is started and stopped, trimmed in and out several time a day, and rarely sees extended high speed runs, will never have a fully charged battery. But it still not a good idea to use MF or AGM batteries

 

[joeyd50]

Thanks guys, the guy working on his motor said the stater got so hot it melted a the glue holding the flywheel center sleeve in.

 

[oldboat1]

Battery type and condition aside, If a rectifier/regulator cooks for lack of cooling water, the stator might be next in line.