When Should I Replace My Boat Batteries?

If you have questions about our products, we want to answer them.  Call us during normal business hours at 1-888-8-OPTIMA and our team will be happy to assist you.  You can also e-mail us at info@optimabatteries.com. 

Today's question comes from David S., who writes:

I love the sealed OPTIMA batteries, compared to the prior lead-acid batteries in my old boat, which always had corroded terminals, requiring yearly cleaning and took eight to ten hours to charge. I have a 2007 Ranger boat that had four Group 31 BLUETOP batteries installed when the boat was new. The batteries are still running strong, but I would like your recommendations on when I should consider replacing those batteries with new OPTIMA batteries?

I utilize three of the batteries to power my 36-volt Terrova trolling motor and the fourth battery for starting my 250-horsepower Yamaha motor and powering my electronics. I have faithfully always made it a point of charging these batteries after using and intermittently when in storage.

OPTIMA Jim writes:

David, thanks for choosing OPTIMA, I'm glad to hear your batteries are providing such good service to you. The fact that you properly-maintain your batteries is a big part of the reason why they have performed so well and lasted so long. Fully charged, your BLUETOPs will measure about 13.0-13.2.

Whenever any lead-acid battery is discharged below 12.4 volts and left sitting in that state, sulfation begins to form within the battery, which shortens lifespan and diminishes capacity.  That makes a  quality battery maintenance device an excellent investment for any vehicle that doesn't see regular use, especially boats that only see seasonal use.

I actually just authored a blog yesterday about testing battery life, which might be a good idea for your BLUETOPs. Taking those batteries to a battery professional, who can perform a load test on them will give you a good idea of the health of your batteries.  When they do need to be replaced, it is important to remember that any batteries wired together in series or parallel need to be identical in age, size and type.

That means if the battery used for starting and your non-trolling motor electronics is properly isolated from the other three, it can be replaced independently of the other three. If you find you need to replace the other three sooner, but two of them still test good, those batteries can be used to replace the starting battery when needed or in other applications.