Maintenance of your Marine Battery

Maintenance of your Marine Battery Having your Marine battery sitting idle for months while slowly running flat between the one or two charges they receive doesn’t do any good to them. If batteries are left in a discharged state, deposits of lead sulfate will collect on the plates and hinder or eliminate the chemical reaction that produces electrical current. Extremely hot temperatures and overcharging will also cause batteries to sulfate. It is vital that your Marine batteries are maintained properly and taken care of. Here are some effective ways to follow in order to maintain your battery. 

Clean Battery is a Happy Battery: Lead-acid batteries are like living things and need to be treated like one as well. They sometimes need tender love and care to achieve long life and maximum performance regardless of battery type, whether it is wet, absorbed glass mat or gel. Fortunately, effective battery maintenance is easy both in winter and during the sailing season.Keep your battery clean. Acid spatter or minor spillage mainly occur in flooded lead acid batteries that can be conductive and encourage a faster rate of self-discharge. Use a mixture of fresh water and baking soda to clean the case that will help neutralise the acid. Rinse off all residue and ensure that the batteries are kept dry in winter storage and in the boat during the sailing season. Dirty or damp batteries invite corrosion at the battery posts and cable terminals, which will limit the battery performance. Atleast once every year, you need to make sure to check for the greenish hue and pitting that reveals the presence of corrosion. If you see corrosion taking hold, please disconnect the terminals and clean them with a wire brush. Apply a thin layer of petroleum jelly prior to reconnecting the terminals. Make sure the terminals are tightly compressed to cable ends and sealed with heat-shrink tubing. Whenever the battery is in service, terminal connections with the battery posts must be tight, and if the battery is the flooded type, check the level of the electrolyte in each cell and top off using only distilled or deionised water. Check electrolyte levels in flooded batteries regularly, particularly before and after extensive charging of batteries that have been completely run down. There is no need to do this with sealed AGM or gel batteries.

Storing your Battery: When the boat is on the hard or in a Marina, it is best to remove the batteries and take them home or to store them in the battery shack at your boatyard. Ideally, cool temperature in the shack is preferred, but not below freezing. Flooded lead-acid batteries in a discharged state can freeze and cause damage to the batteries. The cool storage temperature allows a slower rate of self-discharge as opposed to a hot storage temperature that encourages a faster rate of self-discharge. If you do leave batteries on board, make sure to disconnect the terminals and adhere to a regular charging schedule. The age of the batteries is also a factor that have an impact on self-discharge rates, which can reach as much as 60 percent of capacity in a single month. Older batteries lose their charge faster compared to the newer batteries. Older batteries take more time to charge as well. Charging older batteries once per month is ideal, though newer batteries with full charges can be left for two months before you need to charge them up again. Don’t use an automotive charger as it is not ideal and can damage your battery. A battery charger that delivers 10 to 20 amps should be sufficient in most cases. Use smart marine chargers which are highly recommended as they deliver just the right level of charge and will automatically equalise the batteries. Equalisation occurs after the normal charge cycle is completed and basically means the charger continues delivering a low-level charge until the batteries reach a full charge and each cell is in balance with the others. Make sure to match the charger to your batteries. Having a too small or too big charger may show adverse effects. A charger that's too small won't ever fully charge the batteries and a charger that's too big will cause excessive gassing in flooded lead-acid batteries, resulting in discharge of potentially explosive hydrogen gases into the air. Using an oversized charger may also boil away the electrolyte, exposing the plates in the battery and causing sulfating.

Testing your Battery: Test your lead-acid flooded batteries occasionally for preventive maintenance which will in turn save your money. Having a bad battery in the bank can reduce the life of a good battery, as the current from good batteries will flow to the bad battery bringing the state of charge down. Think of the electricity as water flowing downhill from the good batteries to the bad battery. You want to know if this is happening, so you can replace the bad battery before it does significant damage. Always buy exactly the same size and type of battery to match the others in the bank. Mixing size and type of batteries may cause damage. Use a voltmeter to get a general idea of the state of charge in each battery, but you'll need a hydrometer to test each cell and to see if it is fully charged. Don't try to take a hydrometer reading just after you top off the cells with distilled water. Let the battery charge to mix the pure water into the electrolyte, or you'll get an artificially low reading. Also avoid testing in low temperatures, which tend to make the electrolyte denser and will give an inaccurate reading. The best temperature for testing is around 70 degrees. You can also buy temperature-compensating hydrometers. Battery capacity is listed in amp hours and it is standardised so you can easily make comparisons between batteries, whether they are deep cycle, starter, or dual-use batteries. The formula for figuring capacity is based on a battery's ability to deliver electricity at a constant rate of discharge for 20 hours prior to dropping to a charge of 10.5 volts. A battery which has a capacity of 200 amp hours will run a 10-amp appliance for 20 hours before the charge drops to 10.5 volts. Capacity is also given in reserve minutes, which is the total number of minutes a fully charged battery will run a 25-amp appliance before the charge drops to 10.5 volts. Ideally, deplete only about 20 percent of the capacity of your batteries prior to recharging. Such practices will allow to prolong your battery life and shorten charge times. Flooded, absorbed glass mat and gel batteries are better quality now than ever. Maintaining them is simple and easy, thus helping extending their years of service aboard your boat. Source: Sailing Magazine.Net

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