House Bank of 4 105ah Batteries Life Span

[JeffreyAC77]

What is the estimated life of this house bank in a 2015 R31-cb? Currently all batteries in the boat are functioning fine.

 

[Martin610]

Depends on what chemistry you have. Flooded lead acid can last 3 or 4 years if they are maintained. It's more likely you have AGM. They can last much longer but it depends on several factors such as how they are used, if they are run down to 50% or less, how they are charged. An electronic battery tester is your friend and they are not that expensive anymore. The older resistive type testers are less accurate.

One guy on my dock got 8 years out of his, but he hardly uses them. My boat is all electric so I beat the heck out of my AGM's. If I get 4 years I'm thrilled.

If you have Lithium, different ball game. They are so new, I'm not sure there is enough data to say. The marketing hype of 6,000 cycles is probably a lab number, not the real world.

-martin610

 

[scross]

I agree with Martin. AGM can last up to 5 years or possibly longer if treated really, really well. For AGMs that means never ever under 50% SOC or 12.05 volts. I swap mine at 5 years maximum even if still in good health.
As the old saying goes, “Batteries don’t die, they are murdered!”