Marine Battery Life

[Kojiro]

I'm just about to buy a 4 year old boat (2007 built) with its original house batteries (2 x 140ah) still inplace.

I know it will probably depend on many things but does anyone have a rough idea about how long one could expect them to last.

Also, in Europe any idea about rough replacement cost.

[Jentine]

You are near the end of their life...five years if casually cared for, seven years if well cared for.

[Kojiro]

Thanks for the ehads up.

Once I get to the boat is there anyway of testing them for condition? Other than relying on them and getting let down?

Engine battery is new so I guess that leaves me a bit of margin for safety.

[Lancerbye]

I have some 10 year old Gel batteries that are still going strong. A lot depends on type and quality.

[Jacana]

Just replaced my 9 year old gel battery bank.New lease of life with anchor winch working strongly, recharging via solar good and so far heaps of power compared to my previous aging battery bank.
Bottom line is if it aint broke dont fix it.If you find you have power problems and batteries running down quickly etc etc. replace with new bank.If all is okay leave as is.
Good luck
Cheers
Geoff.

[night0wl]

Originally Posted by Kojiro

Thanks for the ehads up.

Once I get to the boat is there anyway of testing them for condition? Other than relying on them and getting let down?

Engine battery is new so I guess that leaves me a bit of margin for safety.

Here is the best tutorial I'v seen for testing batteries. You can get a hydrometer at nearly any auto parts store for $10-$20 tops

Battery Tutorial

[barnakiel]

Our plain, quality (Varta) was good for 10 years on the starter.

Our quality house bank batteries (Hella) gave us only 3-4 years in service. I must confess the way I treated them was way inadequate much as it could not have been helped given our charging options and cruising style.

I would expect 5 years+ from any decent, well treated, house bank batteries. More from the starter one.

b.