Suzuki outboard motors 1988 2003 repair manual., Page 26Get this manual
3-10 MAINTENANCE Check to be sure the battery is fastened securely in position Check the battery's state of charge and charge as necessary Check battery voltage while cranking the starterVoltage should remain above 9.5 volts Clean the battery, terminals and cables Coat the battery terminals with dielectric grease or terminal protector Batteries which are not maintained on regular basis can fall victim to parasitic loads (small current drains which are constantly drawing current from the battery)Normal parasitic loads may drain battery on boat that is in storage and not used frequentlyBoats that have additional accessories with increased parasitic load may discharge battery soonerStoring boat with the negative battery cable disconnected or battery switch turned off will minimize discharge due to parasitic loadsCLEANING
Keep the battery clean, as film of dirt can help discharge battery that is not used for long periodsA solution of baking soda and water mixed into paste may be used for cleaning, but be careful to flush this off with clear water Do not let any of the solution into the filler holes on non-sealed batteriesBaking soda neutralizes battery acid and will de-activate battery cellFig29 On non-maintenance free batteries with translucent cases, the electrolyte level can be seen through the case; on other types (such as the one shown), the cell cap must be removed
CHECKING SPECIFIC GRAVITY
The electrolyte fluid (sulfuric acid solution) contained in the battery cells will tell you many things about the condition of the batteryBecause the cell plates must be kept submerged below the fluid level in order to operate, maintaining the fluid level is extremely importantIn addition, because the specific gravity of the acid is an indication of electrical charge, testing the fluid can be an aid in determining if the battery must be replacedA battery in boat with properly operating charging system should require little maintenance, but careful, periodic inspection should reveal problems before they leave you strandedBattery electrolyte contains sulfuric acidIf you should splash any on your skin or in your eyes, flush the affected area with plenty of clear waterIf it lands in your eyes, get medical help immediatelyAs stated earlier, the specific gravity of battery's electrolyte level can be used as an indication of battery charge At least once year, check the specific gravity of the battery It should be between 20 and 26 on the gravity scale Most parts stores carry variety of inexpensive battery testing hydrometers These can be used on any non-sealed battery to test the specific gravity in each cell