Load Testing Batteries

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A load test is the only reliable way to determining the condition of a battery in any vehicle. Once you do a load test and review the results, it is possible to judge whether your battery is at fault for a starting problem you may be having.
Keep in mind that a low battery below about 9 volts will not run a bike because the voltage is too low for the ECM to operate properly. You may have sufficient cranking power but the ECM will not fire off the engine so you get a no start condition because the voltage in the battery will crank the engine but be too low to run the engine at cranking time if the battery isn't up to snuff.

Here's a video of a test on a car but a bike would be similar as far as a test is concerned.

YouTube - Poor Man's Load Test (testing battery)

Here's some more info on a load test procedure.
[FONT=Arial, Helvetica, sans-serif]PURPOSE: generally performed because the battery is not performing as expected or as specified. This test will determine the battery’s overall condition and its ability to deliver an engine’s starting current requirement while maintaining a specific battery terminal voltage.[/FONT]
[FONT=Arial, Helvetica, sans-serif]NOTE: Most Load Testers can be adjusted for the temperature of the battery. It is important to best determine the temperature of the battery and adjust the tester accordingly.[/FONT]

[FONT=Arial, Helvetica, sans-serif]TEST PROCEDURE:[/FONT]

[FONT=Arial, Helvetica, sans-serif]Step 1: Battery terminal voltage must be 12.60V or greater to test. If the battery voltage is below 12.60V, charge battery before testing.[/FONT]
[FONT=Arial, Helvetica, sans-serif]Step 2: Connect the Load Tester cables and the test leads of a separate Digital Voltmeter (±0.25% DC accuracy, if the Tester has no direct DC Voltage Meter) to the battery terminals.[/FONT]
[FONT=Arial, Helvetica, sans-serif]Step 3: Adjust the Tester Current Load to achieve ½ the Cold Cranking Amperage (CCA) rating of the battery and apply it for 15 seconds.[/FONT]
[FONT=Arial, Helvetica, sans-serif]Step 4: At the end of 15 seconds, note the battery voltage on the Tester Voltmeter or the Digital Voltmeter and discontinue the test.[/FONT]

[FONT=Arial, Helvetica, sans-serif]TEST EVALUATION:[/FONT]
[FONT=Arial, Helvetica, sans-serif]This test is a pass or fail. Compare the recorded test voltage to the chart below. If the battery test voltage is above the appropriate voltage at the determined battery temperature, the battery tests OK. If the test voltage is below, then the battery failed.[/FONT]

[FONT=Arial, Helvetica, sans-serif]BATTERY TEMPERATURE vs. END OF TEST VOLTAGE[/FONT]​

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70ºF+ ..... [FONT=Arial, Helvetica, sans-serif]9.60V[/FONT]
[FONT=Arial, Helvetica, sans-serif]60ºF[/FONT] [FONT=Arial, Helvetica, sans-serif]........9.50V[/FONT]
[FONT=Arial, Helvetica, sans-serif]50ºF[/FONT] [FONT=Arial, Helvetica, sans-serif]........9.40V[/FONT]
[FONT=Arial, Helvetica, sans-serif]40ºF[/FONT] [FONT=Arial, Helvetica, sans-serif]........9.30V[/FONT] [FONT=Arial, Helvetica, sans-serif]
30ºF[/FONT] [FONT=Arial, Helvetica, sans-serif].........9.10V[/FONT]
[FONT=Arial, Helvetica, sans-serif]20ºF[/FONT]......... [FONT=Arial, Helvetica, sans-serif]8.90V[/FONT]
[FONT=Arial, Helvetica, sans-serif]10ºF[/FONT]......... [FONT=Arial, Helvetica, sans-serif]8.70V[/FONT]
[FONT=Arial, Helvetica, sans-serif]0ºF..........[/FONT] [FONT=Arial, Helvetica, sans-serif]8.50V[/FONT]​

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