Boat Maintenance - Batteries


Boat Maintenance – Batteries

The battery system aboard a boat provides power for most of its on-board systems including lighting, pumps, navigation systems, winches and, most importantly, the engine starting system.

An understanding of their selection, care and proper maintenance for batteries will protect your investment and greatly improve their operational life span.

Lead acid batteries are by far the most commonly used batteries today and can be divided into two categories; deep cycle batteries and engine starting batteries.

Deep Cycle Battery Engine Starter Battery


Check Fluid Levels

If you have a deep-cycle battery with caps, open them and check the fluid level. Add clean ion-free distilled water until you can see a bull’s-eye when you look down into the opening. Be careful not to overfill or the excess liquid will vent out through the caps when the battery heats up during charging.

Charge the batteries and let them sit overnight then apply a 15- or 20’amp load to each one for a minute or two to remove any surface charge remaining.

To check the voltage, use a portable multimeter across the terminals. A fully charged wet-cell battery reads about 12.6 volts across the terminals, AGM batteries 12.8 volts. Anything below 12.4 volts indicates it’s time to think about a new battery, but if you’re in doubt, call an expert.


Ensure Proper Ventilation

If batteries plats are exposed while under heavy load or while being charged, they can glow red hot. If this is ever encountered the operation should be stopped as there is a serious risk of violent combustion.

To ensure against this, make sure to get a battery box with vents to provide proper ventilation for the unit.

Battery Box with Power Fittings & Battery Tester Heavy Duty Double Battery Boxes - Commercial Applications


Charge It Properly

Batteries should never be charged with excess volts as this does permanent damage. The usual charging voltage for a 12 volt battery is 14.2 to 14.4 volts. Excess voltage during charging also promotes gassing and water loss. When a battery is charged it should not gas (produce bubbles in the cells. If this occurs it indicates a problem with the battery cell and should be investigated.

Standard Battery Charger Intelli-Charge Battery Charger


Secure With Brackets

Batteries need to be secured with brackets when in use and it’s important to double check your existing model before and after the boating season to make sure it hasn’t come loose.

Trays are usually made from nylon, so it’s important also to make sure they haven’t split as this can cause leakage the battery to move while on board which could lead to damage and malfunctioning.

Screw-Down Battery Tray Heavy Duty Battery Tray


Test Any Electrics

Installing a battery condition tester is useful in seeing both the capacity of energy left in the batter as well as for testing if it is properly connected.

If a disconnection is caused by the cable on the battery starting to come apart or being damaged, the cable will ever need to be replaced or resoldered using a soldering iron and some plastic sleeve to cover the exposed wire.

It’s also important to check the connections on all switches and electronics once in a while to ensure a proper connection between them and the battery.

Battery Condition Tester Battery & Starter Cables


That's all for now, stay tuned to find out how to take make sure your vessel's ship-shape before taking it out on the water again in our next blog post!

Category: Maintenance

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