When it's time to inspect the leisure use vehicles you've stored during the off-season for spring use, you probably inspect the most obvious items that come to mind such as tires, batteries belts, hoses and fluids. Typically you check tire pressure and condition, making sure that you have the necessary fluids, gas, coolant etc. and a charged battery. The battery inspection is often performed through the most fundamental method; you try to start the vehicle with the ignition. If the vehicle starts, you may feel that you are good to go for the upcoming season, but in many cases you may be headed for trouble. Unless you've maintained the battery during the storage period, it may not be able to deliver its peak performance and service life for the upcoming season. To insure that you get the best performance your battery can deliver, it's recommended that you perform a few simple checks. Remember, before performing any inspection on your battery, insure there are no open flames or possibility of sparks around the battery and absolutely no smoking. Always wear eye protection, protective gloves and clothing.
For a Conventional style battery (those with the liquid electrolyte) you should visually inspect the battery for any apparent problems. These can include dirty or corroded terminal connections, low fluid levels, physical damage such as broken or missing filler caps or dirt and moisture on the battery. If you need to service the battery, it's best to remove it from the vehicle. First insure that the electrolyte levels are properly adjusted. Using distilled water; fill each cell until the level is above the minimum level line on the battery case and at or below the maximum line. Never overfill the battery or leakage will occur. If you discover that the electrolyte levels have fallen below the minimum level lines, there is a possibility that permanent damage may have been done to the internal lead plates in the battery and a new replacement may be required. After adjusting the levels, make sure the filler plugs are secured and the battery is free of dirt and corrosion. If you need to clean the battery, use a mixture of baking soda and water to neutralize any electrolyte that may be on the outside of the battery. Simply brush this on the battery and terminals using an old paintbrush or tooth brush and rinse it off with clean water. Dry the battery using an old soft rag or paper towel and make sure the terminals are clean and free of corrosion. You can clean the terminals with a small wire brush if the corrosion is significant or just brighten them up using a piece of emery cloth.
Now that your battery is clean, it's time to check the state of charge. When using a voltmeter, the battery terminal voltage should read at least 12.6 volts. If your voltage is below this or you've adjusted the electrolyte levels, a boost charge is required. Charge the battery in a well ventilated area away from kids and pets. The variety of chargers you can use to endless but it is recommended that you use an automatic taper type charger specifically designed for Powersports batteries. Don't use a high current or fast charger for the boost charge unless you are familiar with their operation or permanent damage can occur to the battery.
When servicing an AGM style battery, you obviously don't need to inspect the electrolyte levels since the battery is permanently sealed and must never be opened. The cleaning method and charging methods are the same as for the Conventional style batteries. The one feature to note about the AGM battery is the battery terminal voltage. The full charge voltage should read about 12.8 volts. These batteries have a slightly different electrolyte, which influences the terminal voltage.
After you've performed this maintenance, you still may require additional help with your battery. While the battery may exhibit good terminal voltage, it may not be in the best state of health. Deteriorated from corrosion or sulphation, the battery could be seriously short on capacity. To check this condition you may choose to reinstall the battery in your vehicle and perform a very fundamental start test or you could take the battery to a service center and have a capacity test performed. Most battery dealers will perform a simple electronic or electrical resistance test on the battery and be able to tell you the state of health. By knowing the state of health, you can determine the useful life expectancy of you battery. With this information you can decide if you should replace the battery with a new one or reinstall the existing one in the vehicle.
To insure maximum performance and service life for your battery, we recommended that you use either the Yuasa 1.5 Amp or 900mA Automatic Battery Charger for battery maintenance. Both chargers deliver Mistake-Proof Technology to properly charge your battery and both are designed to switch to a float mode once the battery has reached a full state of charge and maintain it there. This feature allows you to attach the charger to your battery for an extended period of time without concern of an overcharged or discharged battery. Also, both chargers are supplied with a Quick-Connect ring terminal harness that can be permanently attached to your battery while installed in the vehicle. This allows you to instantly connect or disconnect the charger from the battery without having to access the battery terminals. This can be a great time saver for those hard to reach battery locations.
It's important to remember, even with the proper care and maintenance of your battery, they will eventually wear out. As with any of the parts on your vehicle, it's usually easier and more convenient to replace them before they fail unexpectedly. With this in mind, you may want to simply replace the battery every few years with a new one.
Link to: Off Season Storage - Detailed article.