FZRSupport: the FZROnline Archive

Hi guys,
I have a charging problem with my bike. The bike has a 13.32 V 4.4 Ah battery made out of A123 cells. The Battery is great and in great shape, never had a problem with it and it always started the bike. Even now when the charging is low it still does the job. I also have R6 rectifier installed on it. I have a voltage monitor mounted in the dash too.
So, the bike starts and runs well, but it only charges 12,9 V with the lights off. Before this happened it was charging 13.8 V with the lights on. So i took the 3 white wires that come from the stator to the VR and measured the resistence and it says 0.9 Ohms ( as far as i know it was supposed to read 0.37 Ohms) . I also measured the AC voltage that comes from the stator and it reads 51 AC volts at 3000 rpm. I don't know that is bad, the stator or the rectifier? Or both?

Hope someone can help me! Thanks guys!

George

trifgeorge wrote:Hi guys,

So, the bike starts and runs well, but it only charges 12,9 V with the lights off. Before this happened it was charging 13.8 V with the lights on. So i took the 3 white wires that come from the stator to the VR and measured the resistence and it says 0.9 Ohms ( as far as i know it was supposed to read 0.37 Ohms) . I also measured the AC voltage that comes from the stator and it reads 51 AC volts at 3000 rpm. I don't know that is bad, the stator or the rectifier? Or both?

Hope someone can help me! Thanks guys!

George

51 Vac is great at the stator. Did you check and get that against all three pairs? A-B, A-C, B-C ?? It's a three phase setup, and it needs to put out 35+ Vac on all three legs.

Now, does it maintain the charge rate of 12.9Vdc when you switch on the lights? If not, your regulator/rectifier is likely bad.

Otherwise I would suspect poor connections somewhere between the stator and the battery-don't overlook the ground paths.

reelrazor,
thank you for the response first. I did get that value no matter the combination of the 3 wires that come from the stator. unfortunately it does not mantain the rate of charge of 12.9 volts when I turn the lights on. Usualy when I was turning the light on, the voltage would drop for a few seconds them come right back up. I think that you are right and the VR is gone. I did not knew that these R6 VR model can go bad too.

Offtopic a little bid for the guys that want to do they own A123 Cells battery:
If you have the OEM type of battery and you are on the road and the VR goes bad and does not charge anymore, you will only be able to ride a few good 7 KMs more from that point because after that distance, the voltage on the battery drops so low that it cannot provide spark anymore ( I know this because it happened to me in the past).
With the A123 battery pack it will run substantialy more KMs ( I've done 15 Kms and the battery is still going without recharge) as the voltage will not go down untill all the Amps in the battery are gone. I think that one of these battery packs would be great for a race bike , as it would eliminate the generator and all the charging components and so reducing weight.

TG,
sounds like corrosion on a wire terminal causing the extra volt drop.

Yg,
I checked all the terminals and wires. they are all good. I'll buy a new VR. I hope I can find one cheap. Thanks.

Update.
I bought an used Yamaha FZS600 VR. I works within the specs. I also checked the temperature that the heat sink on the VR gets to. The heat sink gets up to 58* celsius ( there are about 17*-18* celsius outside). I also checked the temperature with a computer fan on top of the head sink and it showed 41*-42* celsius. So the temperature drops with almost 17* celsius if you put a fan on the VR. Hope this helps someone! Cheers guys!

trifgeorge wrote:Update.
I bought an used Yamaha FZS600 VR. I works within the specs. I also checked the temperature that the heat sink on the VR gets to. The heat sink gets up to 58* celsius ( there are about 17*-18* celsius outside). I also checked the temperature with a computer fan on top of the head sink and it showed 41*-42* celsius. So the temperature drops with almost 17* celsius if you put a fan on the VR. Hope this helps someone! Cheers guys!

TG,
that is good info, I lowered the temp on mine by using thermal paste (for use on a PC CPU)& n alloy spacer to take up the "gap" between the back plane surface and the potting compound. The result was a 4-5 degree drop.

I read elsewhere about VR fans but no one SO FAR has come up with a circuit to turn the fan on and more importantly off when the bike is not running.

Power it off a relay driven by the kill switch. Make sure you have a diode backwards across the relay coil; you don't want a flyback pulse going into your TCI!

DonTZ125 wrote:Power it off a relay driven by the kill switch. Make sure you have a diode backwards across the relay coil; you don't want a flyback pulse going into your TCI!

Don,
you had better draw that for us dumb blighters who are not sure what "backwards" across the relay coil" is

The fan has 2 wires, positive and negative. If I connect the negative wire to the ground, and the positive wire of the fan to the positive wire that goes to the rear light, the fan will turn on only when I turn the lights on. And even if you turn the bike off and forget to turn the lights switch off as well, the fan will stop not matter what, because the lights circuit is routed trough the ignition key. And you also have the 10A fuse (that is for the lights) inline with the positive lead of the fan so no worries at all. Also the computer fan will not draw too much current from the battery (for those that run the A123 battery pack).

YG - too busy malingering to draw pretty pics, need to get back to work. A diode is normally installed in the direction of current flow, +ve to -ve. By placing a diode across the coil terminals with the band at the +ve terminal, no current flows through the diode - that is, until the coil is de-energized, the magnetic field collapses, and the coil turns into a mini spark-coil. The stored energy (the 'flyback' pulse) in the coil flows from one coil terminal to the other through the diode (the flyback or freewheel diode), dissipating the pulse and protecting delicate electronic bits.

Trifgeorge - even better, the bulbs are far better able to handle the flyback pulse and wouldn't need a freewheel diode.

Don,
well I hope the boys & girls understood that, I understood your orig. statement, just worried that those not born with a soldering iron in their hand may have a problem grasping the concept.<BG>