mystery electrical glitch

[brucealmighty]

1982 XJ1100.
The battery is dead when I go to start it. No big deal. I have a charger. Bring it back up to full charge and it's fine, but I'm wondering why it went dead. Good batterys don't just lose their charge for no reason. My charger has an alternator check function. So, letting the bike idle it says that the alternator is bad, not charging. I test again while holding the engine at a steady 2,000rpms and now it says the alternator is good. I don't think that's unusual. From what I've read, the charging system isn't really charging until a certain rpm is maintained. As a rule, I keep it above 3,000 while driving. I'm wondering if this is related to the recent addition of a set of fog lights. I mounted a set of lights and put them on their own circuit directly to the battery. When the engine is running and I turn on the fog lights, I can hear the engine labor down slightly. Even a little tells me that those lights are putting quite a heavy load on the charging system. As to why the battery lost it's charge, and now it seems to be fine, I think it's because I ran the fog lights while driving in traffic, causing the engine to be idling a lot, and not producing enough charge for the battery. Is this to be expected, or should I be looking for a problem with the charging system? I see plenty of bikes with three headlights. Either they have two batteries or two alternators or the charging system on my bike is just not what it should be. What to think?

[petejw]

i reckon u just answered ur own question. :-)
wat are the wattages for the fog lamps?
did u fit a relay?
have u ridden the bike since and not used the fog lights?
have u got an on off switch for the fog lights
orhave u wired to cum on when the lights cum on?
it doesnt take much to drain the electrical system
on these bikes.

[prometheus578]

"A battery of questions..."

We have a weak charging system.
Not really weak... but, it was designed to handle the electrical devices on the bike, but little more.
Foglights will really suck away the juice. There really isn't that much available.
Newer bikes have stronger charging systems so they can run all sorts of accessories.
Turning on your foglights takes voltage away... leaving less to run the ignition system.
Years ago... I had some corroded connections in the system, etc. I put on a travel trunk that had four lights on it. I had to disconnect the thing as when I used a turn signal, the bike would die.
Cleaned up the bad connections, and switched all bulbs to LEDs, no more problems.
Had foglights, too at one time. No problem running at highway speeds, but at idle, battery voltage dropped to 11v or lower and the engine started to stumble.

[brucealmighty]

[QUOTEhave u ridden the bike since and not used the fog lights?
have u got an on off switch for the fog lights
orhave u wired to cum on when the lights cum on?
it doesnt take much to drain the electrical system
on these bikes. [/B][/QUOTE]

I don't know the wattage of the fog lights. I took them off a parts bike. I ran a separate circuit for them directly to the battery, rather than tapping into an existing circuit. I gave the circuit a fuse and a push/pull switch. The big drawback there is remembering to turn them off when I park the bike. I have driven the bike since the incident of the dead battery and everything seems fine. That's why I suspect the fog lights as the culprit. I haven't used them since.

"Cleaned up the bad connections, and switched all bulbs to LEDs, no more problems."

What are LED's?

[Jerry]

What are LED's?

Light Emitting Diodes

LED lights draw less power and are brighter than incandescent (filament style) bulbs. Drawback is that the light is more directional, generally less light to the sides of the bulb. If you look at LEDs marketed as auto bulb replacements you will see a few different styles of 'wrap-around' bulbs designed to have excellent side lighting as well.

The standard flasher designed to work with filament bulbs depends on heat (curent) to opearate. LEDs take less current, so in most cases you need to put in an electronic flasher that does not depent on current draw to operate, or add a load somewhere in the system, which negates the advantage of less current draw.

Do a search on "generator output' and you will see numerous threads on the topic of running additional lights on you XS or XJ.

On the XJ...the alternator is a brush-style design vs the brushless design of the XS. Yamaha recommends changing the brushes about every 10K miles. (Very conservative!) If your brushes are badly worn you may not be getting full current output. Yamaha has the brushes, but a better price can be had:

(Courtesy of TC.)
Partsnmore has brushes for only $5.00ea, you'll need 2,
see below:


quote:
--------------------------------------------------------------------------------

ALTERNATOR BRUSH
For 3-phase alternator systems Must reuse old terminals Fits XJ1100


$5.00US EA.

Part#24-2050
--------------------------------------------------------------------------------


BikeBandit has them close to Yamarobber's prices :

quote:
--------------------------------------------------------------------------------

5: BRUSH 1 43649-001 $29.03
6: BRUSH 2 47357-001 $29.03
--------------------------------------------------------------------------------

When you run your bike at below about 2,500 RPM you are running on battery juice; 2.5K is about the break-even point with stock lighting. If you add more lights the break-even point goes much higher. My guess is that you are draining your battery by running 55w lamps (110w total) which is to much of a load to keep the battery charged.

[brucealmighty]

Thanks for the information, Jerry. I'm doing away with the fog lights. A nice extra, I figured, but hardly necessary. I'll also look into replacing the brushes.

[79XS11F]

addition lighting is a good thing but as has been pointed out don't use it in stop and go traffic. I have additional lighting on my bike as well but only use it when on the highway at highway speeds and higher RPMs. I alway keep my RPMs in the 5k area. This is where the engine likes it and the charging system will do a pretty good job in that range and above.
Rob

[petejw]

if you really wanted to keep the lights
you could try wireing in a relay, there cheap enuff
from an auto parts store.
You should never really run any lights direct
from a battery with out one.
just curious how have u mounted them?

[oseaghdha]

Only thing a relay does is keep you from burning up switches.

[petejw]

it does that 2,
but doesnt it also prevents voltage drop?

[brucealmighty]

I'm not sure what you mean by "relay". I'm not familiar with that. I'll certainly try it, if you think that would help. I did put a fuse in the circuit. I added the fog lights because I figured that anything that helps you to be more visible is a good idea, so I would like to keep them. I'll replace the alternator brushes (may need some guidance there). Also, I'll relocate the switch. Right now it's down by where I think the tool kit would be if I had one. I'll mount them on the handlebars where I can turn them on for highway cruising and off for heavy traffic.

[mro]

mean by "relay"

Only thing a relay does is keep you from burning up switches.

but doesnt it also prevents voltage drop?

Relays/selinoids are but an electrically activated switch.


mro

[Jerry]

I'm not sure what you mean by "relay". I'm not familiar with that.

A relay consists of 2 circuits. One handles the heavy current load of lights or whatever accessories you want to power up. The other circuit is an electomagnet; when you flip a switch or push a button the electomagnet energizes and makes a connection for the heavy-current contacts to flow your power.

Relays then have 2 advantages: you can run shorter lenghts of heavier wire from the battery to the relay and from the relay to the load, and a much lighter wire from the switch to the relay, which makes routing wires easier and you loose less power by having less resistance in the 'load' wires. An additional benefit is that your switches handle only the lighter switching current, not the much greater load current, so you swiches can be smaller, lighter and last longer.

Classic example is the starting solenoid in your car; you don't see battery cable running to your ignition switch. The ignition kicks in a relay (solenoid) that is active as long as the key is in the start position. The solenoid, which does have battery cable running to it, switches the battery juice into the starter. When you release the key the solenoid turns off so the starter does not continue to run.

A solenoid and relay do the same thing; difference is that a solenoid tends to be a temporary contact, like a starter, and a relay is used for longer-term operation, like turning on the AC in your car. This is a simplification, of course, but you get the idea. Both items are an electric switch that uses 2 circuts: 1 powers the load, and the other makes or releases the contact for the load by use of a 2nd, lighter duty circuit. A good many circuits in your average car run through relays or solenoids, including horns, AC, headlight hi-low beam, heater fan, power windows, and other items. Solenoids tend to power really heavy curent applications like a starter, relays are good for up to around 15 - 20 amps max.

Relays can be purchased at any auto store, and the circuit diagram to make them work is generally imprinted on the outside of the case. They generally mount into a matching socket which makes them easy to replace.

[xsilerating]

Additional Lighting

I had the same problem after installing a set of driving lights, relay and all. They simply draw too much load for the electrical system to keep up. Even at highway speeds, the longer they're on they will use more juice than the charging system will produce. I installed a 12volt power alert which monitors the battery and charging system. As long as the system is putting out in excess of approx. 12.8 volts, it won't have a negative effect on the battery. However, at 12.4 the charge is at approx. 75%; 12.2 approx. 50%; 12.0 approx. 25%; 11.8 - 0%. At 12 volts, the battery will have approx. 1 hour of run time left. In my case, once the charge drops below 12.8, I'll shut the driving lights off and give the electrical system a chance to recharge itself. As previously mentioned, you can't use them in stop and go city driving. You'll end up running on the battery itself. As a side to this, to demonstrate the power these lights use, when the system is running at a 14.8 charge and I turn the lights on, it immediately drops to approx. 13.2 and if the revs aren't maintained in the 4K + range, the charge will slowly drop to the 12.6 to 12.8 range. Borderline for keeping the battery in check.
Best answer is to obtain a set of LED lights which, so far, I have been unable to find.
Hope this helps.
Ron

[brucealmighty]

Thanks for all the very useful info. Looks like I won't be keeping the running lights. No big deal. Or maybe I'll just leave them mounted on the bike because they look cool.