What You Should Know about Boat Battery


We’ve yapped about engines, however the preliminary source of power in all of our boats is the battery. The associated wiring, fuses, breaker and other components, and how they’re installed, are likewise extremely essential. If you don’t take notice of these elements and all their corresponding information, you might not get the proper efficiency and enjoyment you anticipate from your rig.

Let’s take a look at batteries. Few years ago there was a 6-volt and then a 12- volt battery, with couple of choices as to sizes, ampere ratings, and specific applications. Today there is a big, confusing list of alternatives offered to us. Do we desire a Group 24, Group 27, a deep- cycle, or a cranking battery? What amp score is best, and what do the ampere rankings actually tell us?

A lot of engines today, whether inboard, outboard, or stern drive, have specific battery needs to guarantee correct efficiency. That efficiency is not just for beginning the engine. With all the electronic components of today’s engines (injectors, ignition, fuel pumps, oil pumps, trim pumps, and electric/hydraulic power steering) significant electrical power is needed to operate everything. When you amount to the engine’s standard requirements, you are often precariously close to, or actually below, the alternator output to the battery at low rpm. Include your marine electronic devices, and you might be reaching well beyond your system’s ability. Idling all the time offshore as you drift or troll may cause your battery to slowly release, dropping its readily available voltage listed below what the engine needs to run correctly. In some engines, a minimum voltage reading of 10.5 is needed simply to keep the engine running. It may still turn the engine over and begin it, but it may not have the energy to fire the ignition and supply fuel through the electronic injectors.


Keep ’em Charged

The majority of us comprehend that when we are buying a new or used boat, the batteries provided might not always be state-of-the-art. If they appear to do the job, we don’t think much about them. However in the warmer climates daily heat is a major opponent of batteries, and can shorten their life significantly. In areas of the nation that require us to put boats in storage for the winter, how the battery is taken care of during this period is also critical to increasing life span. It’s best to keep batteries on a managed “trickle” charger to preserve charge while not in use. A battery that is not charged (and kept charged) can freeze in cold temperatures and a cracked case is the likely outcome.

A battery is like a lot of things in life– use it or lose it! A car battery will generally last longer than a boat battery due to the fact that the car is used frequently and the battery stays charged. When it pertains to boats, the old saying of a battery’s life being two years is pretty well on the mark. You’ll usually get a heads-up when it’s about to give up on you, with the caution being a “dead” battery one morning or a bit slower cranking speed than you’re used to. You plug in the charger, the battery astonishingly comes to life, and you’re off on your journey. You may believe a light was left on, or that the radio memory pulled the voltage down. The truth may be that the battery is sulfating, plates are warped, and it not takes or holds a charge like it when did.

Choose Wisely

How do you identify what’s right as a replacement battery? If the battery’s primary function is to begin and run the engine, you ought to contact your engine maker (or owner’s handbook) to identify the suggested CCA (Cold Cranking Amps) or MCA (Marine Cranking Amps). Much effort by the producer has actually been put into sizing the battery output to the particular engine requirements, so buying a smaller battery exclusively based on price is asking for trouble. Obviously you need to make sure of the current battery measurements to be sure the replacement will suit the area and/or box. A Group 24 battery is pretty common, but Group 27s are larger and aren’t as stretched to provide the power you require. If you have room for the larger battery, although heavier, it might be a smart option.

For today’s larger marine engines, a 750 CCA or 1000 MCA is generally the minimum recommendation for an engine cranking battery. These letters signify the Cold Cranking Amps and Marine Cranking Amp ranking of a battery. CCA is the number of amps a lead acid cranking battery can deliver for 30 seconds at 0 degrees F, and maintain a minimum of 1.2 volts per cell (7.2 volts on a 12V battery). MCA is essentially the same thing, except it’s the variety of amps a battery can deliver in 30 seconds at 32 degrees F. You wouldn’t wish to crank your engine for 30 seconds (tough on the starter) but that’s the basis for the test ranking. Check out the ratings on your prospective new battery carefully and get the size recommended, or even bigger, if you can. The higher rated, more powerful battery will do the job much better, and will do no damage to anything it powers. There’s no complimentary lunch in a less expensive battery, so do not pinch cents here.

Deep Cycle vs. Cranking

If you have an electric trolling motor, thruster, windlass, or other battery powered accessories that draw bigger amounts of existing, you’ll want a separate deep cycle “house” battery for that function. A deep cycle battery is only indicated to be used where high rates of discharging and re-charging take place frequently. A deep cycle battery is built in a different way than a cranking battery, with thicker, heavier plates. The longer, higher amperage requirements of trolling motors and windlasses, for example, would heat up and distort the thinner plates of a normal cranking battery. The cranking battery has more yet thinner plates to offer a fast voltage spike to crank an engine, but is not planned to keep high power output for extended periods. Yes, a deep cycle battery can be used to begin your motor in a pinch, however a two- or three-battery system is extremely suggested to separate the engine battery from the accessory (house) batteries.

The best way to be sure your battery is still excellent is to have it “load tested.” A lot of vehicle parts or battery specialty shops will fill test your battery free of charge and inform you if it’s still functional. Just because it’s gone dead once or twice doesn’t necessarily imply it’s no good. The rest of your electrical and charging systems might require some attention also, as something aside from the battery itself might be the reason for the issue.

Bottom Line

Keep your batteries charged, keep the terminals tidy, and by all ways go out in the boat and “workout” your electrical system as frequently as you can!


Leave a Reply

Your email address will not be published. Required fields are marked *