Annoying Electrical Issue

[Frenchy750]

Hello,

Just got back from a ten day ride from the Kingdom of Rhode Island to Nova Scotia and Newfoundland. The FJR performed almost flawlessly, except for an annoying electrical issue.

Every morning the bike starts fine. But if I run it for a while, then shut it off, when I go to start it back up, it almost seems like the battery is dead. This does not happen every time, in fact it only happened twice in the whole ten days. It happened to me again yesterday in Boston when I pulled over to put on my rain pants. It's sporadic, and once I get a push start, it will start fine the next fifteen times. It's very random, and very annoying.

The bike has heated grips, which I was not using, PIAA driving lights, which were most likely on when the bike wouldn't start, a Powerlet outlet that didn't have anything plugged into it, and a Garmin GPS that is wired to the battery, and was on.

During the trip, one other weird thing happened. My GPS shut itself off, and one of the driving lights blew at the same time. I don't know if that is related or a separate problem.

Any thoughts?

 

[Karmak]

If you find out, let me know-I have experienced this same issue on occasion. So far, I am attributing it to starting it with my driving lights on (I have a separate switch to turn off/on). However, mine starts up again, albeit it seems like the battery is barely turning the starter over.

 

[Frenchy750]

Well, I'm glad to hear it's not just me... I guess.

I did find that the nut that grounds the Powerlet outlet to the chassis was loose, but I don't think that would cause this kind of a problem.

I'm no electrical engineer, but here's what I'm thinking:

a) the constant drain of the 55W driving lights is too much for the alternator and the battery is getting drained. But if that were really the case, I'd think the bike would never start, and I can go for weeks without having the 'dead battery syndrome.'

B) the battery is crap and needs to be replaced.

c) something in the wiring of the accessories is bad.

I'm hoping that there is a d) that I haven't though of.

Someone here must know, at least I hope so.

 

[rfespinosa]

According to Bin-o-Facts here, the Gen 1 has about 120 watts of excess capacity as measured by an owner that installed a voltmeter on his bike. The Gen 1 has a 490 watt alternator, the Gen has a 590 watt alternator capacity at 5000 RPM. Your personal info indicates you have a Gen 2 bike.

Do you know what wattage your PIIA lights use? The Garmin Zumo 550 draws 15 watts. The heated grips about 36 watts.

It doesn't look like you are exceeding the alternator capacity.

Ron

 

[FJRBluesman]

Has the prince of darkness returned... Lucas Electric????

 

[Frenchy750]

Thanks, Ron.

The PIAA lights are 55W driving lights. I use a Garmin GPSMap 60Cx, which runs on 2 AA batteries, so I can't imagine it draws very much.

According to Bin-o-Facts here, the Gen 1 has about 120 watts of excess capacity as measured by an owner that installed a voltmeter on his bike. The Gen 1 has a 490 watt alternator, the Gen has a 590 watt alternator capacity at 5000 RPM. Your personal info indicates you have a Gen 2 bike.
Do you know what wattage your PIIA lights use? The Garmin Zumo 550 draws 15 watts. The heated grips about 36 watts.

It doesn't look like you are exceeding the alternator capacity.

Ron

 

[ionbeam]

Frency750 needs to install a volt meter that monitors battery voltage (as opposed to switched ignition voltage).

The 110 watt draw of the PIAAs is pretty heavy (55W/ea?). The heated grips were off so that is out of the picture. The Gen II max power of 590 watts doesn’t happen until 5k rpm, the output is much lower below that point. How long were you running at what rpm? Did the fans come on? Were the brake lights often on? The fans are a major power hog, the brake lights are somewhat significant at low rpms. A combination of all these things can lead to a depleted battery. A volt meter will show you what is happening.

There is an outside chance that long trips are causing a starting problem becasue things are getting real hot.

Something I posted in another thread:

The FJR stator generates a high voltage AC output which reaches peak current from 5k rpm and up. The Rectifier converts the AC into DC at a voltage in excess of 14.5 volts. The Regulator dumps all the excess power to ground, leaving ~14.5 volts DC on the output terminals of the Regulator. The power that gets dumped to ground makes the R/R always run very hot. The Gen II stator & R/R system is rated to produce 42 amps at 14.0 volts at 5k rpm = 590 watts. Anything less than 5k rpm will produce less than 42 amps. A fixed power load that is acceptable at 5k rpm may overwhelm the charging system at 1.1k rpm (idle) because the stator's current output will be very low.

The battery would like to have a minimum of 13.2 volts to maintain a light trickle charge. Ideally, you would like to see the voltage at the battery terminals running 13.7 to 14.5 volts. In this sweet spot the stator is supplying sufficient current to maintain battery charge and sufficient power to run the electrical devices on the motorcycle without incurring an overheating condition.

When you see 12.8 volts at the battery terminals it indicates that the motorcycle's charging system has reached the end of its capability to supply sufficient current, and the battery is on the verge of supplying 'make-up' power. By 12.4 volts the charging circuit can no longer supply sufficient current, and the battery is starting to supply 'make-up' current and the battery is now slowly being discharged. The more significant event is that the stator is actually over-loaded and getting very hot, entering a zone where it can become permanently damaged.

With a good charging system, and a healthy, properly charged battery I would offer these guidelines for sustained voltages:

≤12.8 volts at the battery terminals – the charging system is over taxed, the battery is being discharged, and the stator is in danger of being permanently damaged.

12.8 to 13.2 volts – entering the danger zone, the battery is no longer being trickle charged and the stator is being taxed to the limits.

13.2 – 13.7 volts – undesirable but sustainable, the stator is taxed but the battery is being charged.

13.7 to 14.5 volts – schweet

 

[El Toro]

The 110 watt draw of the PIAAs is pretty heavy (55W/ea?). The heated grips were off so that is out of the picture. The Gen II max power of 590 watts doesn’t happen until 5k rpm, the output is much lower below that point.
Something I posted in another thread:

The FJR stator generates a high voltage AC output which reaches peak current from 5k rpm and up. The Rectifier converts the AC into DC at a voltage in excess of 14.5 volts. The Regulator dumps all the excess power to ground, leaving ~14.5 volts DC on the output terminals of the Regulator. The power that gets dumped to ground makes the R/R always run very hot. The Gen II stator & R/R system is rated to produce 42 amps at 14.0 volts at 5k rpm = 590 watts. Anything less than 5k rpm will produce less than 42 amps. A fixed power load that is acceptable at 5k rpm may overwhelm the charging system at 1.1k rpm (idle) because the stator's current output will be very low.

This is interesting, and it explains something that I read in the Gen II AE owner's manual that I thought was a bit curious, i.e., that the controller for the heated grips cuts down their power draw when you are idling. I thought this was a "feature," but it looks like it might instead be a necessary "fix."

 

[rfespinosa]

Frency750 needs to install a volt meter that monitors battery voltage (as opposed to switched ignition voltage).
When you see 12.8 volts at the battery terminals it indicates that the motorcycle's charging system has reached the end of its capability to supply sufficient current, and the battery is on the verge of supplying 'make-up' power. By 12.4 volts the charging circuit can no longer supply sufficient current, and the battery is starting to supply 'make-up' current and the battery is now slowly being discharged. The more significant event is that the stator is actually over-loaded and getting very hot, entering a zone where it can become permanently damaged.

I agree a voltmeter would give definitive information to settle whether the problem is related to electrical load and battery state.

I don't agree about the stator overheating. Let's say at a given speed, the alternator will not generate more power than it is physically capable of doing. If it's 5000 RPM then it is 590 watts. If there is a need for more watts, it won't come from the alternator. Granted, it will run hotter the more load on it, but I doubt it will run over 590 watts at 5K RPM.

Ron

 

[C&C]

It sounds as the starter is getting heat-soaked and when that happens, resistance in the circuit goes way-up and the battery has a hard time turning over the engine. Loose connectors at the battery or the starter can contribute, as well as a not so new battery.

 

[Frenchy750]

Thanks for this! I checked the battery terminals, and that connection is tight.

How would I go about checking the connection at the starter?

It sounds as the starter is getting heat-soaked and when that happens, resistance in the circuit goes way-up and the battery has a hard time turning over the engine. Loose connectors at the battery or the starter can contribute, as well as a not so new battery.

 

[ionbeam]

Thanks for this! I checked the battery terminals, and that connection is tight.
How would I go about checking the connection at the starter?

When your FJR is in the process of suffering from what *may* be a heat related starting issue you would need to check for voltage drops between the battery and the starter motor, or a voltage drop across the battery. These tests can't wait, you have to do these checks while it is failing. If you find a voltage drop across the battery it would still be unclear if it is because of an under charged battery or a starter motor that is binding up resulting in excessive current draw. To check for a battery cable voltage drop you would need to measure the voltage drop between the positive battery cable to the starter motor and the voltage drop between the battery ground to the starter ground. If you choose to try this I have already posted a procedure, I can search out a link to it.

IMO, it would be much easier to monitor battery voltage under every day use. If battery voltage looks good all the time, but you still have an inability to start then it is time to do the much harder tests.

If I were to take a wild guess, I would bet on a weak battery.

 

[BladeRunner]

Frency750 needs to install a volt meter that monitors battery voltage (as opposed to switched ignition voltage).
The 110 watt draw of the PIAAs is pretty heavy (55W/ea?). The heated grips were off so that is out of the picture. The Gen II max power of 590 watts doesn’t happen until 5k rpm, the output is much lower below that point. How long were you running at what rpm? Did the fans come on? Were the brake lights often on? The fans are a major power hog, the brake lights are somewhat significant at low rpms. A combination of all these things can lead to a depleted battery. A volt meter will show you what is happening.

There is an outside chance that long trips are causing a starting problem becasue things are getting real hot.

Something I posted in another thread:

The FJR stator generates a high voltage AC output which reaches peak current from 5k rpm and up. The Rectifier converts the AC into DC at a voltage in excess of 14.5 volts. The Regulator dumps all the excess power to ground, leaving ~14.5 volts DC on the output terminals of the Regulator. The power that gets dumped to ground makes the R/R always run very hot. The Gen II stator & R/R system is rated to produce 42 amps at 14.0 volts at 5k rpm = 590 watts. Anything less than 5k rpm will produce less than 42 amps. A fixed power load that is acceptable at 5k rpm may overwhelm the charging system at 1.1k rpm (idle) because the stator's current output will be very low.

The battery would like to have a minimum of 13.2 volts to maintain a light trickle charge. Ideally, you would like to see the voltage at the battery terminals running 13.7 to 14.5 volts. In this sweet spot the stator is supplying sufficient current to maintain battery charge and sufficient power to run the electrical devices on the motorcycle without incurring an overheating condition.

When you see 12.8 volts at the battery terminals it indicates that the motorcycle's charging system has reached the end of its capability to supply sufficient current, and the battery is on the verge of supplying 'make-up' power. By 12.4 volts the charging circuit can no longer supply sufficient current, and the battery is starting to supply 'make-up' current and the battery is now slowly being discharged. The more significant event is that the stator is actually over-loaded and getting very hot, entering a zone where it can become permanently damaged.

With a good charging system, and a healthy, properly charged battery I would offer these guidelines for sustained voltages:

≤12.8 volts at the battery terminals – the charging system is over taxed, the battery is being discharged, and the stator is in danger of being permanently damaged.

12.8 to 13.2 volts – entering the danger zone, the battery is no longer being trickle charged and the stator is being taxed to the limits.

13.2 – 13.7 volts – undesirable but sustainable, the stator is taxed but the battery is being charged.

13.7 to 14.5 volts – schweet

Wow!

A most excellent response!

Foretold is forewarned.

Thanks Ion