Tech Tip - Best Practices Battery Care

Best Practices that Yield Results
Use a battery tender on motorcycles whenever possible.
Please follow the recommended testing and charging practices

Charging
AGM (Absorbed Glass Mat) sealed batteries are the only type of batteries currently sold by Harley-Davidson. AGM batteries contain a fine fiberglass mat between the plates which absorb and immobilize the electrolytic acid, making them leak resistant. The acid is still available to the plates for fast reaction between the acid and plate material to deliver the required starting current.

NOTE:
 Newer Harley-Davidson chargers are specifically designed to properly charge and maintain Harley-Davidson AGM type batteries and are the recommended charger. They safely charge conventional lead-acid batteries as well. These chargers are available from Harley-Davidson in both 5 bank (Part No. 94607- 98) and 10 bank (Part No. 94608-98) systems. These units charge the battery (red light on), maintain 14.6 volts for the proper period of time (blinking green light), and then automatically cut back to approximately 13.1 volts (steady green light), thereby preventing overcharge and the resultant loss of electrolyte. The older chargers only bring an AGM battery to approximately 60 percent of full charge at the end of the charge sequence (steady green light). This low state of charge can lead to battery damage

Overcharging
AGM type batteries are filled with the proper amount of electrolyte and then sealed. If a charger reaches too high a charge voltage (15 volts or above), the water in the electrolyte will begin to evaporate. This water vapor is released through a special one-way relief valve on the top of the battery case. Since the AGM battery is permanently sealed, the water cannot be replenished and the battery becomes permanently low on electrolyte. A battery in this state develops internal corrosion and insufficient ion flow similar to a typical lead-acid battery that is low on electrolyte. This can result in loss of performance and eventual battery failure. A sealed battery with concave sides is an example of one that has been overcharged and has lost electrolyte. Overcharging is a major cause of sealed battery failure.

Undercharging
If a battery charger does not bring the battery to a full charge, several problems can occur:
• The rated battery capacity will not be reached and the charging system may not bring the battery to a full charge, especially in those instances where customers take short rides or ride slowly with their electrical accessories on.
• If the motorcycle is stored in a cold climate, an undercharged battery can freeze and crack. So if you are going to leave you bike for a prolong period of time make Sure to use the appropriate battery tender Also realize the average battery life if maintained properly is 4 yrs. Again if maintained properly.

Tony D. 
Service Manager
Wild Fire Harley-Davidson