Your charging system is putting out the necessary voltage to the battery during a running condition past idle.
Motorcycle battery voltage when running.
You should see the voltage increase on your meter even further up to around to 14 4volts this will vary from bike to bike.
If so this is good.
Then measure the voltage from tab to tab just like before.
Perform a current draw test.
Your motorcycle s charging system check is complete.
The relationship between your motorcycle battery and engine functions much in the same way as a car battery.
Be in the know on whether you actually need a new motorcycle battery or not.
Now switch your multimeter to read ac voltage.
Your battery may even be holding a charge but it s the cold cranking amps that may determine if your battery needs replacement.
The starter should be running at normal speed.
What you are looking for is that all three of the numbers are similar.
With the multimeter on the same settings as above.
A good battery should not drop below 9 6 volts over 10 seconds or so.
Video is your harley davidson or other brand motorcycle seem to be cranking over slowly when starting.
Hook up your dvom in the same manner you did for the standing voltage test and have an assistant thumb the starter.
The alternator is fitted with a regulator that charges the battery while you ride.
With the battery fully charged and functional it s time to test for battery voltage drop.
Replacing the rectifier which converts the alternating current ac from your motorcycle s stator alternator to direct current dc before recharging the battery is also recommended at this time.
While the starter is spinning observe the voltage.
A healthy 12 volt motorcycle battery should maintain a range from 9 5 10 5 volts under the load for a good 30 seconds straight.
This needs to be correctly charged and tested before you start and troubleshooting.
It doesn t matter if the bike starts or not what you re looking for is a voltage reading.
However it s important to note that normal riding may not be enough to fully charge the battery after being completely depleted.
This is a huge part of your charging system.
Does your battery seem to be going bad.
A low or failing battery can cause crazy readings during your testing.
Or you may find it s not the battery at all and a charging system problem instead.
Replace the voltage regulator if the reading is higher or lower than the 13 5 to 14 5 volt range to prevent insufficient or excessive charging.
With the ignition on and the bike not running switch on the lights and you should see the voltage drop slowly as the lights use up the power in the battery.
If your battery is charging perfectly but your motorcycle still seems to keep killing the battery.
No need to go running to a dealership to spend money.
