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Date:   95-06-03 01:28:25 EDT
From:   jearls@mdhost.cse.TEK.COM

>I'd like to hear more about your home-brew voltage regulator
>when you get the time. I don't think it would work on the old FJ's
>because of different voltage output necessary for the "sealed battery"
>newer bikes. Still like to hear about it. Hmmmm--maybe your bike ain't
>one of the "sealed battery" type.

Nope, mine has a regular old battery.  The output charging voltage is
adjustable anyway.  No big deal.

My regulator is a basic switching regulator using a pulse width modulation
chip driving a big hunking MOSFET.  

I did a write-up for some of the FJ pilots on this list right after I
built it and can dig that up for any that are interested.  I have 
schematics in postscript format floating around somewhere too.

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Subj:   Re: Can you help? 
Date:   95-06-06 10:53:42 EDT
From:   jearls@mdhost.cse.TEK.COM

>I only have one very strange problem with my sled. It eats batteries like 
>Rosanne eats Ho-Ho's! I can't figure it out. I go through a battery every 
>three or four months. I'm anal about checking the water level and only 
>filling it with distilled. When it goes, it goes right now. I'll turn on the

>key, all the dash lights come on, I thumb the switch to on and press the 
>starter, CLICK, out go all the lights and then NOTHING. T

How often are you refilling the water in the battery?  There is a very good
chance that your voltage regulator is dead.  When this happens on an
FJ, the alternator rails high and overcharges the battery leading to 
boiling off the water and short battery life.  Check the charging voltage
on the battery as per the shop manual.




  Jeff Earls                  '81 Suzuki GS650G,   '89 Yamaha FJR1200
  jearls@mdhost.cse.tek.com   '93 Kawasaki KLR650, '95 GT Karakoram 

         DoD - AMA - DNRC - OMRRA - KoSPT           SF 21.88

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Subj:   RE: Can you help?
Date:   95-06-06 14:40:50 EDT
From:   benny@fermi.tamu.edu

Agreed, the regulator sounds like the culprit. But while you're at it, 
check the alternator coil too. If the regulator is bad, it may be putting 
extra load on the stator coil, which may in turn be slowly deteriorating. 
Catching this problem early can save you getting stuck in some pretty 
undesirable parts of the world, without a running bike. Don't ask. Just 
make sure that the stator is healthy...

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Subj:   voltage reg
Date:   95-06-02 13:34:31 EDT
From:   chin@skipper.icd.teradyne.com

Just a thought, but the FJ11/12s use the same voltage regulator (and many
other componnents) as a lot of other Yamaha models.    

Junk yards don't have many FJs, but they do have lots of FZ600s and 
FZR600s, and some FZ750s, Fazers, Radians, and V-maxes and they may sell
parts from these at a lower price.  If I needed a voltage regulator, I'd 
look in junk yards for whatever was available and check the part numbers.
I'm using an FZ750 voltage regulator in my FJ1200 right now (same part 
number, just happened to come from a wrecked FZ750).

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Subj:   Re: FJ battery 
Date:   95-08-23 18:10:58 EDT
From:   jearls@mdhost.cse.TEK.COM

>My experience (12 years) with my 84 is that the battery needs to be checked
>often...........make that **OFTEN**!!! I check mine really often, it will
>always accept at least some water, sometimes quite a lot.

If your FJ is doing this, your regulator is shot.  This is common.  The 
failure mode for FJ regualtors is to overcharge the battery and eventually
boil it dry.

The regulators succum to the engine heat.  Yamaha mounted it in the 
alternator which is directly behind the cylinder block.

A new one will cost you ~$200 through Yamaha (in the U.S.)   

Or you can build a replacement one much cheaper if you're handy with a 
soldering iron and a reasonable electronic parts house is nearby.  I'll 
even give you the schematic I created when I built my new regulator.

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Subj:   Re: FJ battery 
Date:   95-08-23 18:43:10 EDT
From:   jearls@mdhost.cse.TEK.COM

Just ask me for the info in a personal mail (don't clutter the 'list'), I've 
got a script that mails the schematic and connection diagram in Postscript 
and an accompanying text file.

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Subj:   Re: FJ battery 
Date:   95-08-23 19:13:34 EDT
From:   as899@freenet.HSC.Colorado.EDU (Lee Carkenord)

I'm pretty sure that I disagree with ur statement that my volt. reg. is 
bad. Since 1984 it's read about 14.75 volts. Yamaha service people say
"that is fine". My service manual says up to 15.0 volts is OK. I've 
personally checked several other FJ's. They have all read somewhere in the
area of 14.5 to 14.9 volts. It would be interesting if all of our FJ people
would put a digital voltmeter on their battery terminals and measure
voltage with engine spinning at 2500 rpm. Then tell us what they read.
Maybe we all have bad regulators???? I truly wonder..........
                                Lee

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Subj:   Re: FJ battery 
Date:   95-08-23 19:30:15 EDT

Regardless, those numbers are at the upper end of what a 12v lead-acid
battery can handle when charging.  

I measured Kory Gill's FJ's charging voltage when he arrived the night before
our WSB trip last month.  His battery was boiled dry.  After refilling it the
charging voltage stabilized at 13.8 or so.  I attribute the dry battery on
the bike having set for too long unattended.

My regulator runs about that voltage.  I haven't had to add water to
my battery since building my own regulator.

Another friend's regulator went on his ZX11 on the same trip.  (Kawi uses
a similar alternator on the ZX).  His output voltage was in the high 14's,
he boiled the battery dry the first day, and was adding water at every
night's stop.

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Subj:   RE: Batteries...
Date:   95-08-23 22:05:19 EDT
From:   benny@bose.tamu.edu

Jeff wrote:

>14.75 volts?  Your regulator is shot.  That's way too high.  Sorry.

How do you figure? Regulators are supposed to run at about 14.5 volts when
in charging mode. I disagree whole-heartedly with your conclusion. 
The reading may be toward the high end of the acceptable range but it 
is, in my experience, quite normal and indicative of a healthy regulator.

Ben

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Subj:   Re: Batteries... 
Date:   95-08-23 23:57:10 EDT
From:   jearls@mdhost.cse.TEK.COM

Heck, I'm not trying sell you guys regulators.  I'm just pointing out that 
in _my_ experience, a charging voltage of over 14.5 is going to charge the
battery hard enough to cause it to overheat and evaporate the water.

I've been nearly stranded by boiled batteries on a couple of occasions and
decided to deal with the problem.

Yes, I'll agree that the FJ service manual calls for a charging voltage
between 13 and 15 volts.  When I measured my stock regulator it was out of
spec on the high side.  My homebuilt v.reg puts the voltage in the 14 to
14.2v range and I no longer have to add water.  I still check it regularily.

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Subj:   Re: Batteries... 
Date:   95-08-24 00:19:06 EDT
From:   as899@freenet.HSC.Colorado.EDU (Lee Carkenord)

I bought a new Yuasa YB14L-A2 exactly 24 months ago. I have since ridden
24704 miles. I serviced the battery 14 times. Each time, on average, I
added 3/16 inches of distilled water to bring level up to "full".
This battery seems nice and lively still. After "resting" overnite, the
no-load voltage at the terminals is about 12.65. When new, the same
reading under the same condition. So I think the battery is gonna last a
while longer. I also wonder why Yamaha design called for such a high
charging voltage??? Seems like it would be detrimental to battery life,
especially since most people don't check their battery as often as I do.
                                        Lee

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Subj:   Re: Batteries...
Date:   95-08-24 10:26:43 EDT
From:   daveking@yoda.wpafb.af.mil (Dave Kingsland)

I just looked at my service manual.  In the appendix of the '84 manual,
it states that the no load charging voltage should be 14-15V.  In the
electrical section of the manual, it says 13-15V. In the maintenance
specifications of the '86 FJ1200 supplement, it says 14.2-14.8V.
In the supplement for the '89 FJ, it says 12V nominal.  In the supplement
for the '90 FJ, it says 14V nominal.  I think that the spec from the
'86 supplement is most correct.

Here is another data point on FJ regulators:

I have burned out three voltage regulators on my FJ so far. Each one has
put out 14.5V.  All three died after some steady highway riding at 70 mph
or so in hot (90+ deg.) summer weather, where the road temp was much higher.

I certainly believe that sustained high heat kills FJ regulators.  After
burning out, the regulator will normally put out 15V.  However, once it has
burned out, it has a catastrophic failure mode that kicks in after about
30 min. of steady highway riding, where suddenly the voltage will begin to
vary erratically and reach as high as 18V!  I found this out by riding
around with a digital voltmeter attached for a week.  The battery can boil
completely dry in about an hour when this happens.  Otherwise, when the
voltage regulator is working correctly, I lose almost no water.

Question for Jeff Earls:  Jeff, where did you mount your homemade voltage
regulator?  The zener diode needs to have a heat sink, doesn't it?

Dave Kingsland

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Subj:   Re: Batteries... 
Date:   95-08-24 11:10:33 EDT
From:   jearls@mdhost.cse.TEK.COM

>Question for Jeff Earls:  Jeff, where did you mount your
>homemade voltage regulator?  

Under the tailpiece.


>The zener diode needs to have a heat sink, doesn't it?

What zener diode?  The FJ alternator uses an energized field coil in a
feedback loop to control the output current as a function of the load
on the battery.  It's not like many motorcycle _generators_ that just
pump out current as a function of engine RPM.

My regulator uses a PWM (pulse width modulation) chip, a "big hunkin'" 
(engineering term ;-) MOSFET, and a few other assorted components.

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Subj:   Re: Modifications
Date:   95-11-08 11:03:03 EST
From:   daveking@yoda.wpafb.af.mil (Dave Kingsland)

CrobertA@aol.com writes:
 > 
 > PS  Just read the rest of the day's replies to this thread.  Dave K's
 > comment reminds me that the one time that my battery was shot and this
 > happened, it was after an all day ride and the battery had boiled dry.
 > It was old and using water anyway and I may have just been careless about
 > topping if off before leaving.  I'm still on my original regulator and
 > I've felt my battery after a long ride and it's not even very warm, let
 > alone hot.  I don't think overcharging is the fault on my bike even
 > though if it was overcharging it would act more or less the same.

Remember that the battery doesn't have to get hot for you to lose water.
You can ride around indefinately with a mild overcharging problem.  Your
battery will use a little water and won't last as long, but you can keep on
going like this for a long time.

I remember when we discussed overcharging a few months ago that several
people measured their charging voltage at 14.5-15V, and didn't know that was
causing their battery to lose water. (A new FJ regulator puts out 13.8V)

On my bike, the mild overcharging suddenly becomes severe (ie. 17V) in the
middle of a long ride and strands me out on the highway somewhere.  Other FJ
riders never get past the mild overcharging stage.  Since my bike has eaten
three regulators like this, I start to worry when the mild overcharging
problem shows up, knowing that I am living on borrowed time.  It really,
really, REALLY sucks breaking down in the middle of nowhere.  Especially
when the nearest shop doesn't have an FJ regulator in stock.  This time,
as soon as the mild overcharging starts again, I am going to build myself
a Jeff Earls special (thanks again for the schematics).

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Subj:   Re: Why dry ?
Date:   95-12-27 10:08:14 EST
From:   as899@Freenet.UCHSC.EDU (Lee Carkenord)

>
>I did a round trip of 1700 km during the Christmas period and all went well
>except for my one exhaust bolt that came loose about 200 km from home and 
>about 300 km from home I stopped and the motorcycle did not want to start
>- we had to push it. When I got home we discovered that the two outer cells
>of the battery was dry.  I think this was caused by the heat from the engine

>warming up the battery and vaporised the water in the cells.
> 
>Has this ever happened to anyone on a long trip ? 
>Does anyone have an explanation why this happened  and / or  solution for 
>this problem ? 
>


This has happened to several of us, Borne. It *IS NOT* caused by engine
heat. My observation.........It is caused by a combination of 2 things.
It has happened to me. First, most FJ's have a charging system that 
"overcharges". Second, because of that, you have to watch water level
very, very closely. If water level is allowed to drop too much, it
pre-maturely ages the battery. This makes the "overcharge" even worse.
Now you're caught in a vicious circle. Battery uses water more rapidly,
overcharges more........etc. Pretty quick, you can't keep water in it at all.
The solution, which truly has worked for me: Start with new battery, be
religious about pre-installation prep. Then, never, ever, let water level
get too low. 

        Jeff Earls, who is yamahafj member, also has a method of dealing
with this problem. I'm sure you will hear from him, he's studied this problem
pretty closely. 
                                Lee

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Subj:   Re: Why dry ?
Date:   95-12-27 11:04:40 EST
From:   as899@Freenet.UCHSC.EDU (Lee Carkenord)

>
>The battery was pretty warm when I disconected it. Was this because 
>of the overcharging, engine heat or a combination of the two.
>I surely hope  JEFF will be able to help solving this one.
>Borne' Denyschen                  93  '  YAMAHA FJ1200  

Yes, mine was hot, really hot, when it happened to me. But a new battery 
does not even get slightly warm from engine heat. Older/used batteries in
an FJ get hot (in my experience) because:

They are near the end of their life.
They are low on water.
They consequently are being vigorously overcharged.
                                        Lee

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Subj:   Re: Why dry ?
Date:   95-12-28 10:13:05 EST
From:   as899@Freenet.UCHSC.EDU (Lee Carkenord)

>> >Could you remember if it had some kind of insulation in the box where 
>> >the battery are kept ?
>> I think there was some thermal insulation surrounding the battery box,n
>> well, i'm not sure, though...
>
>I am planning on  fitting  some space blanket or foil roof sealer in 
>the box. I will let you know if it make a difference.   


Borne, this is interesting....... Let's think about it.......I have mixed
feelings on your idea. I think I am mostly against it. I am of the opinion
the battery is not being heated by the engine. Let me tell you why.

I install a new battery in my bike. I go riding in 45 degree F. weather.
Immediately after my ride, I pull out my battery. It is *COOL* to my touch.
That tells me the engine does not heat the battery. When an FJ battery
DOES heat up, it's from battery aging/overcharging. If you wrap the battery
in insulation, it will just get hotter.  The heat is coming from an
internal source. A better solution would be to ventilate the battery box.

Give the internally generated heat an easier escape route.  The above 45
degree incident is something I have experienced with my 84 FJ. Also, on
my 84, there is a fairly extensive flexible metal shield just to the rear
of the cylinders. I would imagine this would keep some of the engine heat
away from battery. Not sure if all FJ's have this shield. Actually, when
you look, the battery really is quite isolated from the engine.
Comments???
                                        Lee

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