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How do I test my 12 Volt battery and charging system?

 

Whenever handling your powersports battery, make sure you wear eye protection and take the appropriate safety precautions associated with handling lead acid batteries.

Following are three tests you can perform on your battery and charging system.

Static Battery Voltage Test

  • Prior to conducting this test, make sure the battery has not been recently charged. You must wait at least one hour after charging your battery to conduct this test.
  • Adjust voltmeter to DC volts (20 volt range).
  • Place voltmeter leads to the battery terminals. (positive to positive and negative to negative)
  • Read voltage and refer to the chart below.

Methods of Checking Battery Condition

State of
Charge
Syringe
Hydrometer
Digital
Voltmeter
5-Ball
Hydrometer
100% Charged
w/Sulfate Stop
1.28012.80v5 Balls Floating
100% Charged1.26512.60v4 Balls Floating
75% Charged1.21012.40v3 Balls Floating
50% Charged1.16012.10v2 Balls Floating
25% Charged1.12011.90v1 Balls Floating
0% Chargedless than 11.80v0 Balls Floating

Starting Load Test

  • Adjust voltmeter to DC volts (20 volt range).
  • Place voltmeter leads to the battery terminals. (positive to positive and negative to negative)
  • Watch the voltmeter as you start your motorcycle.
  • If the voltage drops below 9.5 volts, the battery has very low capacity and should be replaced.

Charging System Test

  • Adjust voltmeter to DC volts (20 volt range).
  • Place voltmeter leads to the battery terminals. (positive to positive and negative to negative)
  • Start your motorcycle.
  • Bring engine RPM's up to approximately 3,000
  • Compare the voltage reading to the specification in your owner's manual.
    (Note:the voltage reading should be approx. 13.8 - 14.5 volts to properly charge an AGM battery.)



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