Help. I dont understand why FZ6 died.

[Moldmaker]

For the past 2 years I have read several threads about the implied shortcomings of the battery and charging system. It seems that whenever there is an issue of a battery going flat or the addition of load to the electrical system, one of the common replies is to “ride the bike for a while with the engine revving above 5000 rpm because it doesn’t start charging until this speed”. I have to assume that this is based on the alternator specification in the service manual: 14 V/310 W at 5,000 r/min. I had my doubts as to whether this was an accurate statement, and decided to measure the output.

First of all, it should be noted that the FZ6 has a standard 3-phase alternator with NO rotor current control circuitry. In other words, it will generate voltage across the output terminals as soon as it begins rotating, increasing with speed, as it uses permanent magnets in the rotor. In addition, the regulator/rectifier module is an external package, mounted just below and to the left of the rear fuel tank mount. This allowed for easy access to make measurements.

I began by leaving the lights and 4-way flasher on for about ½ hour to create some drain on the battery as I have the dual headlight mod. Voltage dropped from 12.2 V to 11.0 V. After splicing in a shunt between the positive terminal of the regulator and the lead going towards the rest of the system I started the engine. The attached chart shows a graphical display of the measured values listed here:

Engine off- 11.25V
Started from cold fast idle- 12.8V, 20A, 1600 RPM
High beam and emergency flasher on- 12.2V, 20A, 1500 RPM
Warmed up, low beam, emergency flasher off- 12.2V, 15A, 1100 RPM
Warmed up- 13.8V, 21A, 2000 RPM
Warmed up- 14.0V, 22A, 2200 RPM
Warmed up- 14.0V, 22A, 4000 RPM
Warmed up- 14.0V, 22A, 5000 RPM
Warmed up- 14.0V, 22A, 8000 RPM

After gathering this info, I hooked up an additional ammeter at the main fuse block to monitor system usage. Following the same approach as before, I measured both positive and negative current flow consistent with the rpm points listed above. The point of no charge was about 1400 RPM, with battery drain below this speed and charging current above. The maximum positive charging current measured was 4A @ >2000 RPM, as the regulator was showing an output of 22A. I didn’t let this run for more than 5 minutes so I never reached a point where the battery would reach a full charge state.

My data leads me to the following conclusions:
1- The alternator/regulator package produces it’s full rated value of 310W (22A x 14V) at 2200 RPM and this value never increases with engine speeds above this point. So, the advice to “keep it revved up or it will never charge” is misguided. Just normal engine speeds are enough to get full charging potential.
2- As I stated, I have the dual headlight mod. With this, my bike draws a consistent 18 amps under steady operation. Of course, as brakes are applied or turn signals are activated, this load momentarily increases above 18A to a discharge condition. I am confidant that the normal total electrical draw is just under the system limits, which is why I haven’t had a problem with a battery discharging. I did have a regulator fail when the bike was under warranty, but no problems since.
3- The numbers don’t lie: I don’t believe that this electrical system can handle more that an additional 40-45W of constant current draw without eventually discharging the battery. Momentary use is one thing but with a battery capacity of only 10 A/H there is very little headroom. The effects of this can be masked/minimized by hooking the battery up to a charger on a regular basis, but you will not be able to maintain charge by running the engine unless:

total system demand<charging potential
??? amps<22 amps

I hope this is helpful to some of you as I spent some time debating whether or not to get involved in the discussion. Comments or questions, just fire away..

[Moldmaker]

Originally Posted by skeleton

1 Hp = 750 Watts

A larger alternator wouldn't really cut into our available horsepower, would it? My guess is Yamaha was saving on cost of parts.

Probably a combination of cost, weight and power savings. 80-95% of the target owners will never add anything to the system. All of the additional wattage would have to be dissipated as heat, and it's already quite warm under the seat. And, a larger altenator would add to the rotating mass of the crankshaft, with some effect on the ability to build revs quickly.

Again, there was some thought put into this charging system, and it shows in the price/performance equation.

[MasAce]

Do you ride with the high beams on?
I had a problem with the battery a few weeks ago in Daytona. I had the high on when I was sitting in traffic for about 90 minutes after the Honda 200. I pretty much didn't have to use the throttle to creep along with traffic. That led to a stall and I had no juice to restart. Fortunately there was enough to operate the computer and fuel pump, so I could push start. Needless to say, I'm a lot more discriminating about turning on the brights now.

[SnapRolls]

Originally Posted by skeleton

1 Hp = 750 Watts

A larger alternator wouldn't really cut into our available horsepower, would it? My guess is Yamaha was saving on cost of parts.

I was being a wee bit sarcastic. Sorry. Old Habit.

Given the way these engines & accessories are designed, it is pretty much dictated by the space available and I guess the extra power wasn't needed in the R6.

My arthritic hands need electric heat and I'll be selling my FZ-6 this fall for one reason.... the alternator doesn't deliver the amps to keep my old arthritic body comfortable in cooler driving conditions. I went out today (about 53 degrees) and needed both the heated grips and the gloves. Yes, I am a wimp but it's not my personal choice. It's the cards I've been dealt and I refuse to sit at home when I can work a solution... in this case my FZ6 disappoints. But it's the only one!

[SnapRolls]

Moldmaker... GREAT WORK! Thanks for the data... I've been looking at the voltmeter but not doing "research" so it's nice to see your data.

I agree that the headroom allows for about 40W, and your full output at 2200rpm sounds about right. My gut feel from glancing at the voltmeter said about 3500 and I added a comfortable margin.

Thank you so much for posting your data!

[Binary Jay]

I'm glad my StreetPilot only uses:

6 watts maximum @ 13.8 Vdc

I guess I'll be fine... I was kind of wondering what kind of power dog that thing was.

[segue00]

Originally Posted by SnapRolls

I don't have a problem when I only add 35W (grip heaters or vest or heated gloves). I am comfortable running an added 70W (vest and grip heaters) and cutting off equipment at stoplights. The 105W (grips, vest, and gloves) will drain the battery even at keepiing all moving revs over 5k and cutting stuff off at stoplights.

You don't use all the cr*p in LA do you?? Here's your chance to explain the importance of Location, Location, Location when deciding where to live (and ride!)

(signed in cold blood (very cold))
Snap

You run them all at the same time at full heat? Get a controller for your heat gear. You don't need them all on full blast at the same time. Or, alternate the usage.

Also, you have heated grips and heated gloves, too? Kinda redundant.

[SnapRolls]

All have electronic controllers... I try not to run them on all at the same time, but when you're cold, you are cold.

The grips are great except my forefingers and the backs of my hands still get cold. The heated gloves take care of that. My hands are the toughest part of this problem. Once they get cold, they lose circulation, and I need real heat... not just insulation.

So... redundant yet... and I like it that way. I hate to say it but I'm cruising e-Bay and cycletrader regularly. Love my FZ6... need more electrical power. Yes I'm a wimp.

[Fuzz Bomb]

Snap- was the question about heated gear for me? I do have a heated vest (the DIY version), but I don't really want it until it gets to 55F, which is pretty unusual in LA. I have no idea what it draws. I will be installing heated grips before my ride back to Portland. Once that's done, I might add a switch to turn off my second headlight when the heated grips are on. Sorry to hear the need for heat is driving you away from our bike.

I have had batteries in cars go kaput suddenly and completely. It seems like the low miles on his bike might indicate the battery has not been kept well charged. Isn't that harder on them?

[ImOk]

Thanks for that RPM info Moldmaker. 5000 seemed ridiculous to be trying to keep RPMS that high all the time while riding in slow traffic.

I have a happy conclusion to my ordeal. I charged the battery with Battery Tender but first I measured the voltage, It was 10V. After charging for several hours the voltage was at 13V at which point I took it off BT to go for a short ride. The bike started up np.

I was trying to figure how anyone could even keep the bikes all the time at 5000 RPM or more . There is no way. Went home and the charge was still about 13V.

P.S. Before the ride I replaced my headlight with and I added a headlight modulator from KRISS on the high beam.

So now I am wondering how much wattage to the rear turn signals use.

How much wattage more do my HID headlights and my rear turn signals use (since are always on to use them as running lightsl.

[Binary Jay]

Replace the bulbs with the plug-in LED equivalent and they should draw less power if you're really *that* concerned.

[MrVvrroomm]

Originally Posted by Binary Jay

If I get really stuck in traffic, I pull the clutch in often and rev it away... people think I'm just being a jerk showing off but oh well. I'm not sure it actually does enough good to matter but I guess it doesn't matter.

You're kidding right?

[Binary Jay]

Of course.

Originally Posted by MrVvrroomm

You're kidding right?

[SnapRolls]

Information on batteries, all kinds, can be found at Battery University

Also attached are some notes from the site.

55 degrees? Ahhhh, that sounds nice! Maybe today I'll see that Fuzz Bomb!

[FZTurtle]

Heh, I'm waiting for it to HIT 55 ;p I think about heated gear when it's below 25, but I don't ride much then anyway. The roads are covered in crap, cagers are driving with fogged windows, and no one wants to go with me anyway.