Voltage going down as I accelerate, even with a new battery! What has happened?

[ES44AC]

So, I rode last week and about 30 miles from home I got the P0582 Code - low voltage. That was on the 2021 factory battery. The voltage goes down to about 11.5v-11.7v moving at 60 MPH. When you stop, it runs back up to 12.3v. The Battery cables are tight.

Today, I replaced the battery with a brand new Yuasa (same p/n). The battery voltage still goes down the faster you go?!

What has happened?

I'm going to schedule an appointment, hopefully next week.

 

[Snowbelt Spyder]

Could that code have been P0562? Hopefully, you got a Yuasa YTX-24HL. Anyway, we've said it on here a million times. Before you replace a battery, you have to give it an activation charge with a battery charger. It takes close to 20 hours at 2 amps. Dealers and stores don't take the time to do that. If not, then your alternator is trying to run your Spyder and activate your battery at the same time right now. The 1330 alternator is usually up for that, but it would affect your troubleshooting. But, assuming that all of that was done, or will be done, your ground speed doesn't matter, it's your RPM. With your motor started up and warmed up, at 4000 RPM, your voltage at the battery terminals should be 13.5 - 14.5 VDC. Making sure that you have your meter set to DC volts, of course.

Historically, the fleet has had issues with the slipper clutch on the alternator drive shaft. At idle, if you aggressively blip the throttle, you would hear a disturbing squawking noise. Definitely something that would raise a concern to you that would be a new noise. It could be slipping at higher RPM, plus the ignition system alone is drawing more power. There's nothing regarding ground speed that I can think of that would draw an excessive amount of power. Otherwise, something else in the charging circuit perhaps, or inside the alternator itself. Just for the heck of it though, you could check Fuse F3 in the Left Side fuse box. That's left side as you're sitting on the bike.

Except for some other connection issue, such as a bad ground, they'll just have to go through your system and see what's what. Measure the alternator output current. It was time to replace that old battery, anyway. Good Luck.

 

[Mrmikey]

The voltage goes down to about 11.5v-11.7v moving 60 MPH. When you stop, it runs back up to 12.3v.

12.3V should be the voltage of a battery at rest (it's a bit low actually, but close - it should be around 12.8V once the surface charge is removed). When the engine is idling, your system should be putting out somewhere in the vicinity of 14V+ depending on the state of charge of the battery . From your voltage dropping to effectively 0 when the engine is revving, you have absolutely no output current from the alternator at all.
By the voltage dropping as you accelerate and not rising, it's proving out the system is not generating enough current to charge the battery and/or run the necessary electrical load required to run the machine, i.e. ECM, fuel pump, lights etc. Guessing, I'd say that the load on a running machine would be 10A+ minimum.
It could be caused by numerous things, a bad connection somewhere, either grounds or B+ but losing that much current, I think you'd see visible smoke or smell the heat being generated.
If the battery is a total dud, that would do it as well by drawing all the current that the alternator is producing, but you said it's a new battery... Still, it's possible, but not high on the scale of actual.
So I'm guessing you've got three options. Not knowing if the Spyders' system is internally regulated in the alternator or via an external controller, you could have a bad alternator or controller. Or the alternator is not being driven by the engine as SS above suggested.

 

[Little Blue]

I would have that new battery Load Tested, looking for results of 12.8 volts minimum.

I would really like to get 13.1 volts.

Your Spyder should be able to put out 14 volts.
Where did you get your Battery?
Even a New Battery can be 'Bad' if it was not charged correctly.

Battery or wiring or Alternator. At least one or sometimes ALL three.

Good Luck on Your Mission.

 

[ES44AC]

Could that code have been P0562? Hopefully, you got a Yuasa YTX-24HL. Anyway, we've said it on here a million times. Before you replace a battery, you have to give it an activation charge with a battery charger. It takes close to 20 hours at 2 amps. Dealers and stores don't take the time to do that. If not, then your alternator is trying to run your Spyder and activate your battery at the same time right now. The 1330 alternator is usually up for that, but it would affect your troubleshooting. But, assuming that all of that was done, or will be done, your ground speed doesn't matter, it's your RPM. With your motor started up and warmed up, at 4000 RPM, your voltage at the battery terminals should be 13.5 - 14.5 VDC. Making sure that you have your meter set to DC volts, of course.

Historically, the fleet has had issues with the slipper clutch on the alternator drive shaft. At idle, if you aggressively blip the throttle, you would hear a disturbing squawking noise. Definitely something that would raise a concern to you that would be a new noise. It could be slipping at higher RPM, plus the ignition system alone is drawing more power. There's nothing regarding ground speed that I can think of that would draw an excessive amount of power. Otherwise, something else in the charging circuit perhaps, or inside the alternator itself. Just for the heck of it though, you could check Fuse F3 in the Left Side fuse box. That's left side as you're sitting on the bike.

Except for some other connection issue, such as a bad ground, they'll just have to go through your system and see what's what. Measure the alternator output current. It was time to replace that old battery, anyway. Good Luck.

I'll definitely check the fuse Friday. The battery is charging. Its is the 24HL battery. Got it from my dealership.

 

[ES44AC]

Could that code have been P0562? Hopefully, you got a Yuasa YTX-24HL. Anyway, we've said it on here a million times. Before you replace a battery, you have to give it an activation charge with a battery charger. It takes close to 20 hours at 2 amps. Dealers and stores don't take the time to do that. If not, then your alternator is trying to run your Spyder and activate your battery at the same time right now. The 1330 alternator is usually up for that, but it would affect your troubleshooting. But, assuming that all of that was done, or will be done, your ground speed doesn't matter, it's your RPM. With your motor started up and warmed up, at 4000 RPM, your voltage at the battery terminals should be 13.5 - 14.5 VDC. Making sure that you have your meter set to DC volts, of course.

Historically, the fleet has had issues with the slipper clutch on the alternator drive shaft. At idle, if you aggressively blip the throttle, you would hear a disturbing squawking noise. Definitely something that would raise a concern to you that would be a new noise. It could be slipping at higher RPM, plus the ignition system alone is drawing more power. There's nothing regarding ground speed that I can think of that would draw an excessive amount of power. Otherwise, something else in the charging circuit perhaps, or inside the alternator itself. Just for the heck of it though, you could check Fuse F3 in the Left Side fuse box. That's left side as you're sitting on the bike.

Except for some other connection issue, such as a bad ground, they'll just have to go through your system and see what's what. Measure the alternator output current. It was time to replace that old battery, anyway. Good Luck.

P0582 was a typo. P0562 was it.