12 Volt System Shows 15 Volts

[MIRELOS]

What type of batteries?. Some gels charge at a higher voltage.

[Maine Sail]

Originally Posted by MIRELOS

What type of batteries?. Some gels charge at a higher voltage.

The deep cycle GEL batteries I know of (Sonnenschein, East Penn, Trojan) charge at lower voltages. Charge a GEL higher and you develop gas bubbles in the silica gelled electrolyte and on a boat this will become permanent damage..

Can you provide us a link to which GEL batteries charge at 15.0V or more..?

The OP also has Motolite batteries and Motolite and I don't believe they make a GEL..???

[MIRELOS]

on my last boat I had 2 Lifeline gels for the house totaling 800 ah, had solar and wind; the charging was at 14.1. they lasted 10 yr.

[Gone2long]

Originally Posted by Gone2long

Rod,

Thanks a lot for the thorough explanation. Mixed w. the other comments above, I have a MUCH better handle on what is going on. I absolutely do not want to mess with the system myself, especially if it apparently is working as it should.

Will do the research and multi meter checks suggested by folks on the thread, and hopefully the system will turn out to be working as it should. There is no physical evidence to suggest a problem at this point, but I intend to buy a 40 watt, 12v fan, and I want to make sure all is in order before wiring it in.

Thanks again,

G2L

Tried to post the photos I promised earlier, but, cannot get them up at the moment. Will try again soon. See specs posted earlier for more - G2L

[Gone2long]

Originally Posted by Gone2long

Rod,

Thanks a lot for the thorough explanation. Mixed w. the other comments above, I have a MUCH better handle on what is going on. I absolutely do not want to mess with the system myself, especially if it apparently is working as it should.

Will do the research and multi meter checks suggested by folks on the thread, and hopefully the system will turn out to be working as it should. There is no physical evidence to suggest a problem at this point, but I intend to buy a 40 watt, 12v fan, and I want to make sure all is in order before wiring it in.

Thanks again,

G2L

The 2 house batteries are Motolite (a Philippine company) 12V batteries. The exact type seems to be the "Enduro" model which is a "low maintenance" battery which, unfortunately, seems to have been designed for use in autos (not boats) run in a hot, tropical climate. There are no holes for adding water, and, as inferred by others, that is probably not a good thing. The model number on the batteries is 35MF N70L D31L

Thanks to all,

G2L