One of the less desirable situations on a boat as an owner is allowing for the accumulation of marine battery corrosion. I have, without a doubt, been required to handle corroded batteries as a 200 ton master captain. When it comes to vessels, here is how you need to prevent and remove marine battery corrosion. 

What Is The Primary Issue With Marine Battery Corrosion

Without a doubt, corrosion is a major issue when it comes to boating in the Southeast. I have seen boat owners fail to inspect batteries which leads to mechanical problems when out on the water. 

One of the most notable problems that arise from corroding batteries is the ability to start the engine. Unquestionably, marine engines require a significant amount of power to spin and start. The corrosion limits the amount of energy delivered from the battery to the motor. 

The voltage travels from the battery to the lugs where cables are connected. Boat battery cables facilitate the power flow from the battery to the engine. Unfortunately, the build up of corrosion creates a barrier between the terminal and the cable, thus reducing the required amount of energy to start a marine engine. 

I personally have faced this issue on one occasion. At the time, I was less experienced and could have resolved the problem on the water rather than requiring a tow back to the dock. 

Battery Failure As a Result Of Corrosion

Let’s make it clear that battery failure is twofold. As mentioned before, corroded terminals fail to deliver the correct voltage to start a marine engine. On the other hand, boat batteries sustain long term damage from the inability to receive a proper charge. 

It should be noted that onboard batteries are charged while the engine is running. The charging is accomplished via an alternator within the engine. For this reason, boats throttled up to high RPMS charge batteries at a faster rate. 

To compare, corrosion impacts the ability of a boat to start due to insufficient cranking power. Conversely, the alternator is cranking out power to return to batteries to complete the charging cycle but is unable to do so. Charging voltage is minimized or eliminated as a result of the corrosion on the cable. The corrosion impedes energy flow return back to the battery via the cable and lug. 

Unfortunately, over time, failure to properly charge an onboard battery leads to the battery failing. The battery or batteries will require replacement as they will no longer hold a charge. Understand that this can be avoided with proper maintenance. I suggest you monitor for corrosion to avoid spending money unnecessarily. 

How To Prevent And Remove Corrosion From Marine Batteries

I have maintained vessels for over thirty years and can tell you for a fact that battery corrosion is preventable. Additionally, if you fail to prevent it, corrosion can be removed before replacement is necessary. 

How To Prevent Battery Terminal Corrosion

Without a doubt, the best method to extend the life of a battery is to prevent corrosion. First off, ensure that the battery cables are snugged tightly on the lugs. I recommend checking the battery lug nuts on a monthly basis to ensure that they have not loosened from vibration. 

Secondly, battery terminal coatings are available to prevent the formation of corrosion. After tightening, I suggest applying CRC Battery Terminal Spray on a monthly basis or earlier if needed. The spray is highly effective at preventing the onset of battery corrosion. 

How To Remove Battery Terminal Corrosion

In the event that your onboard batteries have begun to accumulate corrosion, the problem must be resolved immediately. 

Without question, you will need to take action to prevent further build up before your batteries fail. 

First, I recommend disconnecting the cables one lug at a time and brushing the wire ends and lugs with a wire brush. The wire brush is stiff bristled to remove the most stubborn corrosion buildup. 

Second, after the most prominent corrosion is removed, mix up 3 tablespoons of baking soda with 2 cups of hot water. I suggest dipping the cable ends into the mixture for five to ten seconds. Next, pour a small amount of the mixture directly onto the battery terminals. The terminals are likely to bubble profusely. Once the bubbling stops, wipe dry with a clean rag. 

Third, reconnect the battery cable to the terminals. Importantly, ensure that the cables are well snugged to prevent a recurrence of corrosion buildup.

Lastly, apply the CRC battery terminal spray as the final step. The combination of snugging the lug bolts tight and the spray is likely to stop the issue from repeating. 

Remove And Prevent Marine Battery Corrosion

 To save yourself from spending money, I suggest taking proper care of your boats’ onboard batteries. Boat batteries are not cheap, so the time required to inspect, tighten, and spray lugs are well worth it. Without a doubt, one can of CRC spray will last you more than a season. Importantly, keep the proper sized battery nut wrench and brush onboard in the event you’re facing an issue while out on the water.