Bad battery or regulator? 2008 gti 130

[Mitch619911]

Was out riding and shut off my ski just to have it slowly crank after and never start again.
I tried to troubleshoot and found:

• Battery dies after about an hour of riding and is tested at 12.3ish volts after.
• Battery can be jumped with a little pack and fires right up just fine and while engine running stays around 13.8ish volts also if I let it run at the dock for 10 minutes and shut it down it'll start right back up.
• Battery has been tested by AutoZone and they said it tested great and nothing was wrong with it.​

Am I dealing with a dead battery that's giving out more power than it's getting thus dying while ridding?
Or is this a regulator or electrical issue? Can the regulator be tested? (Where is it? Oh, I think it's on top of the fuel tank!)

The battery does have a sticker of 4/17 so about 3 years old.
I am going to try to test the charging system with my volt-meter as the manual shows.. I don't have an inductive ammeter currently.

Thanks for any help!

 

[val-e-vue]

Was out riding and shut off my ski just to have it slowly crank after and never start again.
I tried to troubleshoot and found:

• Battery dies after about an hour of riding and is tested at 12.3ish volts after.
• Battery can be jumped with a little pack and fires right up just fine and while engine running stays around 13.8ish volts also if I let it run at the dock for 10 minutes and shut it down it'll start right back up.
• Battery has been tested by AutoZone and they said it tested great and nothing was wrong with it.​

Am I dealing with a dead battery that's giving out more power than it's getting thus dying while ridding?
Or is this a regulator or electrical issue? Can the regulator be tested? (Where is it? Oh, I think it's on top of the fuel tank!)

The battery does have a sticker of 4/17 so about 3 years old.
I am going to try to test the charging system with my volt-meter as the manual shows.. I don't have an inductive ammeter currently.

Thanks for any help!

It sounds like the charging system works fine (13.8V). That will keep your battery charged if your battery terminal connections are clean and tight. The fact that you can always jump start implies that your starter connection and engine ground connections are good.

I would work on your battery terminal connections and if you continue to have problems, replace the battery. Definitely work on your connections first.

 

[Mitch619911]

I tested the regulator with 3 multimeters and none of them moved, all stayed at 0L.
Sound right?

 

[Mitch619911]

It sounds like the charging system works fine (13.8V). That will keep your battery charged if your battery terminal connections are clean and tight. The fact that you can always jump start implies that your starter connection and engine ground connections are good.

I would work on your battery terminal connections and if you continue to have problems, replace the battery. Definitely work on your connections first.

I cleaned the terminals probably a month ago and they were in great shape.. didn't even need to be cleaned but I still did. I'm probably gonna go buy a $110 AGM battery from Autozone hoping that fixes it.

 

[val-e-vue]

I tested the regulator with 3 multimeters and none of them moved, all stayed at 0L.
Sound right?

The best test of your voltage regulator is with your meter on DC volts. Connect to the battery terminals prior to starting the ski. Record reading (probably 12V + or - depending on the state of your battery), start the ski and expect the voltage to increase. As you rev the engine, I would expect it to increase to 13.8 VDC.

I'm not familiar with the static test, where you are measuring resistance.

 

[skiasylum]

I tested the regulator with 3 multimeters and none of them moved, all stayed at 0L.
Sound right?

The regulator regulates Vdc to a maximum of 15 Vdc from the rectifier. Thats all it does. With the ski running at 5000 RPM you should see 14.5 Vdc +- .5 Vdc and if the voltage is above 15Vdc you have a bad regulator and the regulator/rectifier needs to be replaced. The rectifier part, through diodes, changes Vac from the A/C alternator to Vdc and the minimum at 5000 rpm is 14.0 Vdc to keep your battery properly charged. The stator part of the A/C alternator is three phase, the three yellow wires from the stator. One test of the stator is continuity test between the three phases of the the stator. There should not be continuity across any of the three pins of the stator connector, if there is you have a short between a phase/coil of the stator and it would need replacing. It sounds like you were testing your stator and that is a good test. The other test of the A/C alternator is the amp output test with an ammeter.

You are on the right track making sure you have a good battery, I researched the reliability of a Autozone battery test and depending on what equipment they were using there is still a possibility your battery is still not up to specs. A three year old battery is probably near the end of its useful life depending on how it was maintained anyway.
It sounds to me like your regulator/rectifier is good and after you install the new battery and the battery still does not hold the proper charge to start and maintain the electrical system of the ski you then have an amp problem (power output) which is either a bad A/C alternator or your amp draw form the ski, corroded connectors and cables, equipment add ons, etc is pulling more amps than the charging system is rated for.