Cabin Lights Dimming, Even While Connected to Shore Power

[bahamabreisus]

Seems to me, most 12V elctrical problems, always come back to bad battery. If they are 3 yrs old or more, they should be replaced. Thats about all you can get from boat batteries

 

[highlife34]

So, what replacement batteries are recommended? Should all 3 be the same? I have 3 deep cycle batteries now, not sure how old, but one or more is failing. Have had to use "Both" when starting, and have used the emergency start feature twice now. Going out Saturday with some friends and dont have time to test and troubleshoot. Hopefully new batteries solves the problem.

In limited research, looks like I can replace with lead acid or AGM, which is 1 1/2 times the price of lead acid. Recommendations? Looks like the AGM better meets SER requirements in CCA and reserve time.

Thanks