Maintaining Batteries

Starting a new set of articles for RVers. The last series on Inspecting an RV before you purchase it is available on my website at http://rv-inspection-service.com.
This series will be on maintenance of the RV. Please if you have any suggestions or areas of interest, let me know.
These will not be in any order of importance. Basically, I will start with whatever area hits me as a topic to write about. Today’s topic is going to be on Batteries as this seems to be an area that a lot of people disregard until it is too late and they have to replace them.
As I mentioned in my inspection articles on batteries, there are two basic types; maintenance and maintenance free. Maintenance free does not mean you do not have any maintenance, it just means you have less maintenance to do. They should probably call the limited maintenance. So lets start with them.
Tools you will need to maintain batteries include a battery cleaning brush, adjustable wrench and a hydrometer.
Maintenance Free Battery Maintenance starts with cleaning. Periodically, you need to clean the terminals of the batteries. Corrosion of the terminals will reduce the available voltage and current available to the rig. Many problems with maintenance free batteries come from dirty/corroded battery terminals. The corrosion comes from the gases that escape from the battery during normal operation. Once you have cleaned the battery terminals and wire connections, use some Vaseline on the terminal and connection to seal out the elements. There is no real guidance that I know of as to how often to clean the battery. A lot depends on the environment. So as a guideline I would look at doing the maintenance every 6 months or so.
Maintenance of regular batteries is a little bit more complicated, although not that bad. Besides cleaning the battery terminals, you also need to check the fluid levels in these batteries. This should be done when the battery is fully charges and cool. Why? The battery fluid level will vary depending on the temperature and the charge. A fully charged battery at 70 degree will have a different fluid level than a battery that is discharge at 50 degrees. The level of fluid should be just covering the plates inside the battery. If the battery needs fluid, use distilled water. Tap water is loaded with chemicals that can be harmful to the battery. However, if you do not have distilled water and the water level is low, tap water is better than no water. You should check these batteries every month or so. At the most every time you change oil. You can determine the state of charge for maintenance batteries with a hydrometer. Simply insert the tip into the cell and withdraw some of the liquid until the bulb or level in the hydrometer floats. Read the state of charge from the gauge inside the hydrometer.

Source: Tips of the Day