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The Doctor · (This post was last modified: 09-16-2015 06:23 PM by The Doctor.)

So my battery has been going to shit lately. Over the past two weeks I've had push start my bike twice, and today alone I had to do it three times. The battery is only about 6ish months old, but it was a cheapo from autozone. I usually have one good try to start the bike, and if it doesn't start up right away, then it's time to push start it.

So what do people think? Just a bad battery, or could my charging system be taking a dump? Are there any indications of a charging system going bad? Gonna be trying to get a new one from autozone after I get off work today, just to get me by.

Rev. That Guy · (This post was last modified: 09-16-2015 07:08 PM by Rev. That Guy.)

all can be tested.

but a quick indicator that your charging system is good is that the bike will run after push starting. If the battery is good but the charging system is bad, the bike will only run as long as the battery can supply it power. If the battery is no good but the charging system is fine, the bike will, in theory, run indefinitely as it makes enough electrical power to keep itself running - sans a short in the battery or regulator that would be dumping voltage excessively. Now it could be the electrical system is not making enough power and it is OK to run the bike but allowing a VERY slow discharge or something like that... then you need to find out why.

but it sounds more to me like the battery is just not holding a charge.

quick test: Get the bike running, check voltage at the battery. Idle voltage should be no less than 12.5-12.7VDC. Off idle or revving should be no more than 15VDC (slightly high but ok) but no less than 13.1-13.2VDC. If volts are lower or higher when revving, you have a bad component in the charging system. Specifically if they are high it is likely the battery has shorted cells, if low, likely bad regulator or stator. If voltage is low on idle it is likely a bad regulator.

The battery, when charged and no load on it (key off) should be in the 12.0-12.5V range.

To check the stator, you can do it one of a few ways, but the best is to check voltage from the stator when running. This will be AC voltage. At idle, stator unplugged while bike is running, should read between 18-25VAC between any 2 of the 3 wires and should be exactly the same reading regardless of which 2 of the 3 you check. If low, you have a bad winding in the stator. It wont be high as there just isnt any way it could be as voltage output would be dependent on motor speed. If the battery is no good and the charging system is the only thing letting the bike run, then you will not be able to do this test as the bike wont be able to run without the stator plugged in.

if that checks out ok, and the bike can run with a dead battery, your regulator is likely fine - and were back to the battery.

- J

ars0n · 09-16-2015, 08:02 PM

moar blinker fluid.

The Doctor · 09-16-2015, 10:29 PM

I don't have a voltmeter. Tomy stole mine. But I connected it to the battery in the car and let the car run for about 10-15 minutes. The bike started once, but was dead when I tried to start it up a second time. So I got a new battery and will be trying it out tomorrow. Will keep y'all posted. I miss my OEM battery.... Lasted... over 3 years and a ridiculous amount of miles.