I'm hoping this may be familiar to someone else (someone who hopefully figured it out)

I noticed last night that when I roll the throttle off and back on again to shift, that the lights momentarily flicker and not just a small amount. They almost go out and back on again.

I have some accessories added, running lights, radar detector, heated grips. Fortunately, the radar detector (Whistler Cruisader) also has a voltmeter on it, so I know that, although I'm pushing the charging system harder than intended by manufacture, it is still seems to be charging at cruising speed. In urban riding conditions, it will run eventually run at a deficit with the brakes on at a traffic light light, but it does come back fairly quickly once I get back on the highway. Without the brakes applied and idling, it gets about 12.2 volts (with all accessories turned on). The no load voltage is also about 12.2 volts without the engine running, so I think the battery is okay even though it's been put through it's paces. Cruising voltage is between 13.4 and 14.0 volts with everything turned on and with the battery holding a decent charge.

I know the generator is supposed to put out 200 watts at 5000rpm, so I would expect a small dip in output when the throttle is rolled off and back on, (such as when shifting), but not to the point where the lights almost go dark and back up again. I noticed it happening at cruising speed, so its' not just happening in urban riding conditions when the charging system is working harder.

Here's are some possibles I'll continue to check out, but if anyone else has experienced exactly these symptoms, you might be able to save me some time and headache. Or, maybe this is a normal thing and I just have to live with it.

- Bad ground
- Loose wire
- Marginal battery condition
- Generator or regulator/rectifier problem

I'm hoping to replace most lights with LED's shortly, which should give me more headroom.

Any help would be appreciated.

Cheers - Brian

most batteries are 12.5-12.8 at no load.....start turning off accessories and watch the voltage

side note....ya got too much crap attachedditch the grips or the extra lights and get a battery

my oppinion.....ignore me....everybody else does

I agree too much load. Btw ed are you home

I agree with ken and frank, the alternator and reg/rect is struggling with the increased current demand being placed on it by your add-ons. Smallish bikes like the GS have almost no extra capacity in the electrical system

As it is a DC circuit you can use Ohms law to determine power. If you put a DC ammeter or clip-on in the + lead from the battery, run the engine and turn everything on it will indicate the max amount of current flowing in the system. Take this figure and multiply it by 12 and you will get a figure for the amount of power in Watts being consumed. If the max output of the alternator is 200W at 12v, any more than about 16.5A in the system indicates its being overloaded. The fuse should blow at or about 20A but I wouldnt like to say how the alternator or reg/rect will behave when operating at close to 20A for long periods.

Wow! You guys are just no fun at all! I hope you don't say "Yes, officer, you're right I was going to fast and exceeding speed limit" when you get stopped for trying to have too much fun. (lol)

I do realize I'm asking a lot of the electrical system, but I commute all winter in Canada (west coast) and mostly in soaking wet, barely above freezing temperatures for about 4 months out of the year. But even some summer nights can be quite cool on the hands. You'd want heated grips as well. As for the driving lights, I've already had one accident where the driver said he "didn't see me" although I was wearing light coloured gear and my high-beam on. The driving lights I've added do make a difference. A cop even stopped me on the highway because he was curious and owned a bike himself so he was thinking of doing the same thing. I've had others confirm unsolicited that they do make me more visible. Even though I can't rely on them, I'd still rather have them.

So sorry, boys . . . but I'm not giving them up. And the radar detector uses very little anyway. The GS500 has turned out to be an excellent and inexpensive commuter bike, so I'm not about to go out and lay down a few thousand more bucks just to get a bike with a bigger alternator. I like the GS and I'm sticking with that too.

Given this, the best long term solution in my view to deal with underpowerd electrical systems (which should not be a problem with today's technology - don't get me started) is replacing all the filament bulbs with LED's. (with the exception of headlights and driving lights) If you do the math, two brake lights and two signal lights (when engaged) amount to 85 watts. Similar LED's would be no more than 12 watts, and there are some excellent LED products emerging on the market that can easily put a filament bulb to shame. If you add in all the 3watt guage bulbs, parking bulbs, etc., and you are now quite a ways down from stock consumption of wattage required to run the bike.

However, that still does not explain the temporary drop when rolling off and on the throttle., which is something I'd like to determine whether it's a fault, or a result of over taxing the system. I'm hoping somebody else had the same symptom and found out it was a ground problem, battery problem or whatever.

Thanks for all the "fatherly" advice anyway guys.

B

P.S. - Always, always, always, fight a speeding ticket and be ready to plead down if you know you won't get off.

I have jusy looked at the stated wattages for the various bulbs and have calculated that under certain circumstances the lighting system alone will pull up to about 165w, in addition you can loose a few more watts in the ignition circuit and keeping the battery charged.....call it 175w in total......then add your extra lights and heated grips.


This is whats happening:
You roll off, engine speed drops, alternator output drops. The electrical system still needs the same power, the reg/rect is operating right at its limit (20A and 200W) and as a result is slow stabilising the voltage flowing into the bikes electrical system.....upshot is you get a brief voltage drop until it can raise and stabilise the voltge in the system, during the voltage drop the lights dim, then when the reg/rect catches up it releases full voltage back into the system and they brighten up.

Disconnect the grips and extra lights and see if the headlamp still dims.

Thanks, Sledge. I'll give that a try.

If you find some LED tails that output more than a filiment bulb please show me. I am an LED fanatic, but dont think there are any that can take over the rear tails yet. Unless you customize and use high powered leds.. you will have to worry about heat dissapation. I am contimplating about making a set of led tails for myself, but that will probably be down the road because I have a few other projects on the table. If you do run into some LEDs that you find outperform the bulb, PLEASE inform us/me. Thanks

Shuluke

Still waiting on a supplier on ebay to some 1157's in for the tail/brake. They are 27 LED SMT bulbs. My experience with SMT's is they are very bright. given there are 21 around the circumference and 6 on the end, I expect they will compete with filaments. They're not cheap though. Hopefully they'll come in soon and I'll be glad to give my opinion of them.

By the way, the fading seems to have disappeared as mysteriously as it started. Not sure what was going on. I'll be keeping an eye on things to see if it comes back.

Hey Bval,

If the seller is warden_jp2002, then they are not brighter.. Usually SMT are brighter, but most are either underpowered or a cheap knockoff and are not as bright. Also, if they are not regulated, they will not have a very long lifetime. Keep me informed otherwise.

Here's the site I'm going to order from:

http://frickinbrite.com/catalog/product_info.php?cPath=41_118&products_id=333

These are the brake lights. They also have the same in 1156 yellow for signals. Just look around the site.

I'm thinking of replacing every bulb on the bike except for the headlight and driving lights, although if I can find an MR11 6 SMT Yellow bulb, I'd probably replace the driving lights as well. Although they help a bit in fog and to light the road underneath and beside the bike, they don't really add too much visibility (for me) and was not my main motivation for getting them. They are primarly for "being seen". (although you can't rely on them) 

I also saw someone on this site who has blue bulbs in the instruments and I like that look. I have a Cruisader radar detector that is also blue backlit LED so it would look great with matching instrument lights.

that is a very simple mod , however there is a reccommended LED to use , i bought a set of ebay , and they didnt show in the day , and they werent that bright at night

Search the LED replacement and u shall find 

Thats the same idea as the guy on ebay. Anyway.. Once you get them in, can we see output pictures? night and day as well as one side led and one side bulb?  

Quote from: bval on January 21, 2008, 07:43:04 PM
Here's the site I'm going to order from:

http://frickinbrite.com/catalog/product_info.php?cPath=41_118&products_id=333

These are the brake lights. They also have the same in 1156 yellow for signals. Just look around the site.

...

Thats the same idea as the guy on ebay. Anyway.. Once you get them in, can we see output pictures? Night and day as well as one side led and one side bulb?     I have been working on hid projectors for my car all weekend and school starts tomorrow. But ill take pictures of my led retrofit once its completed.

Shuluke

Sure, I can take photos, but the camera senses light differently than our eyes. I took a shot of my bike this morning from the back. I've added a second tail light on the fender as I do a lot of commuting and like the extra bright light. The second light is LED and with the stock tail light. In a photo they both look the same, but to the eye, the LED stands out more.

The problem with earlier 1157 replacement LED's is twofold. One, is they tended to cram as many low power LED's as possible and made them all face directly at the lens. While bright in the center, they were small, so some made them about 2" in diameter to compensate, but again, they were very directional because they didn't make use of the reflector. They then started to get the idea to put them around the outside, but only a few in comparison to how many were facing directly at the lens. Plus, many cheap ones flooded the market that were not using very high powered LED's.

Secondly, Surface Mount ones (SMT) are much brighter than a standard LED. These ones in particular have 21 mounted radially to make better use of the reflector, plus 6 facing directly at the lens. It's a gamble, but I believe these ones might be more on the mark to compete with filament bulbs and at $20 each, I hope I'm right.

Well I only ask for a picture because I dont know if you have a light meter or not.. If you have a light meter that would be awesome!

I totally agree with you that some SMT leds are brighter than regular leds. The problem that I am trying to warn about is that they might be underpowered. This is usually done to increase the lifetime of them because they are not regulated. LEDs are very very sensitive to voltage changes. Although if you grab a 1.5 volt LED and apply 2 volts, it will be brighter, but the lifetime is severly damaged. instead of 10000 hours it will be less. With bigger voltage changes, the LED is damaged more. I dont know about voltage changes in motorcycles, but on a car, it can range from 12 to 15 volts I think, maybe more. A change like that could damage your LED or its lifetime.

What I think are needed are the high powered leds. Cree leds or similar would do a great job with brightness and visibility, but like I said before, the heat disapation might be a problem.
I have one cree light for my trunk of my car (98 camry) with a HUGE trunk, and it lights up everything inside. I am only powering it with 350mA but it can run with currents as high as 1 A. Thats incredible for a LED smaller than an eraser off a pencil, with a stock heatsink as big as a quarter. I have ran it at 1 A and put a small heatsink on it(touching the stock heatsink), and after 30 seconds.. if you want the imprint of the heatsink on your hand, just touch it. I left the heatsink on for good measure and dropped the current to 350mA.

I guess with pictures please write your comments on which one you think is brighter in the day, and at night. I am not trying to say that all LED bulbs suck, you might have found the good ones, but I just want to warn you about brightness. Good luck! 

That's good information. Thanks.

I have to figure out another problem with my bike before I go down the LED path (priorities, priorities). But when I do I'll be sure to provide a good review of them.

 edited

Maybe we should move this topic to a new thread on LED's . . . the reason for originating this thread seems to have disappeared for now.