Boat battery/electrical issue...dead optima blue top?

Question

Alright,

has anyone had issues with Optima blue-tops not taking a charge? This battery is the 34M, bought it 05-13-08--so its 33 days old.

Ive got a 21 maxum, with dual batteries. One battery is one year old and then I bought one a month ago... Ive got two amps for my stereo running off one battery and the other one is supposed to be there to start the boat,. the stereo shop installed a battery isolater--why would the bran new battery be DEAD??

I hooked the battery charger to it last night,. it gets about 30% charged then the charger error's out and wont charge any further (2A &15A)...the charger is one of these digital deals from sears and its new as well.

I didnt leave anything on, havent used the boat in 4 weeks--its been sitting in my garage all this time. What would cause this battery to drain and fail? I emailed optima as well, asking if this is common

My only option is to take the boat to the shop and pay more $$ to have it checked out

Answer 1

okay, about batteries.

automotive cranking battery is a bad idea on a boat, you want a marine cranking battery.  marine batteries are made with thicker plates and heavier cases to withstand the shock and vibration and marine environment.

marine deepcycle batteries are for running your accessories.  Any cranking battery (auto or marine) will be dead in no time if used in a deep cycle application.

optima blue top is a great battery, it comes in both cranking and deepcycle variations, make sure you got the deepcycle.   It's probably more battery than you need, but on a boat that's a good thing.

do you know how the isolator is supposed to function?  seems like maybe you're expecting the engine to charge both batteries but maybe it's not?

One problem is, your charger only has 2A & 15A settings - 15 amps is too much for a gel cell battery, and 2A will take forever.

you need a charger with a specific setting for "gel cell" batteries, and a 10A charging rate.

These batteries won't tolerate the same charging algorithm as wet cell batteries.

Answer 2

put some standard batteries in the boat and see what transpires.

What kind of batts are u using,, the marine type or the automotive type??

Auto batts are good for starting motors because they have much more cranking amps.

Marine types are for lights, instruments etc. they hold a lot and let it out slowly.

Optimas are gel batts , expensive,,so i would not bother to buy them. I'm cheap.

i have a digital charger and its too sensitive. I prefer the more common type with  needle indicator dial.