VFR is overcharging, tried two regulators

I have a '96 Honda VR750. If you don't know, these things eat
regulator/rectifiers like candy.

I upgraded my regulator as preventative maintenance, because I plan to
run 150 watts of heated clothing, plus extra lighting, and I had no
doubt the stock regulator would burn up, probably when I'm far from
home on the interstate in the rain.

I replaced it with a Suzuki GSXR regulator, which several other VFR
owners had said they used sucessfully. My problem is that the bike
frequently runs around 15v, sometimes as much as 15.3v, even after just
starting it. It won't do this at idle, of course, but at crusing RPM.

I thought my first regulator must be bad, so I replaced it with another
GSXR regulator, and it still did the exact same thing.

Any ideas on why this is happening? I also upgraded the positive and
negative wiring coming out of the regulator when I put the first
regulator on. The stock wiring was showing signs of extreme heat, as
is common on this bike.

Another GSXR regulator user said his VFR goes up to 14.9 with the new
one in. Ok I think I just figured it out. The GSXR regulator just
puts out 15.3v, thats it. My upgraded wiring has almost zero losses in
the wire, so that voltage makes it to the battery. On most stock bikes
there is an amount of loss in the wiring, and Suzuki make the GSXR
regulator to put out higher voltage to compensate for that. Ya think?

I might have to use a 6 wire regulator, one with a sensing wire.

-Ryan

 

Suzuki doesn't make the regulator, they outsource it from a supplier.

Regulators are being made to accomodate two different types of
batteries now, the maintenance-free (it has acid in it but the acid is
held close to the plates by fibreglass wrapping to assist in reversing
the chemical reaction that separates electrolyte into water and sulfur)
and the traditional flooded-cell battery (where the electrolyte just
sloshes around in the cell and you keep losing a lot of water to
boiling off)...

The maintenance-free battery may require as much as 16 volts to charge
it, and, if the GSXR that your regulator was meant to go on comes with
an OEM maintenance-free battery, you're likely to see higher
voltages...

Is your battery actually overcharging, or is the number you see on a
voltmeter just overloading your brain because the number doesn't match
what's printed in a book?

What kind of battery do you have on the VFR? A flooded cell battery?
Does the electrolyte level keep dropping, due to overcharging?

If the electrolyte level keeps dropping, what are you adding to the
battery, distilled water? It makes no sense to keep adding *distilled
water* to a fully charged battery when the *electrolyte* level is low,
you're supposed to add fresh electrolyte to a fully charged battery
that's low on "water"...

Yeah, yeah, I know. Motorcycle manuals say to never add *acid* to a
battery, and I'm going to get a bunch of guys posting links to battery
maintenance FAQ's. The manufacturers of motorcycles are worried about
product liability lawsuits from people that don't know the difference
between acid and electrolyte. If you pour pure sulfuric acid into
water, you might get splashed by the reaction.
If you pour water into pure sulfuric acid, the water will
instantaneously BOIL and it will throw acid all over the place. Only
trained personnel should be allowed to mix acid and water, but you can
buy 50% electrolyte in an auto parts store and have enough to last a
decade...

And, what kind of alternator are you talking about? Do your VFR and the
GSXR in question both have permanent magnet alternators or are they
both excited field alternators?

In a permanent magnet alternator, the output depends upon the magnetic
flux density of the permanent magnets, the number of coils in the
stator windings, and the impedance (inductive reactance) of the coils,
which changes with RPM, getting higher at higher RPM...

A permanent magnet alternator will put out far more than 15 volts if
you run it open circuit, i.e., disconnected from the battery and
lights. When connected, the permanent magnet alternator's voltage is
"sunk" into the lighting system and the battery, for the most part, the
ignition system takes very little current. The current that can't be
burned up as heat in a shunt type regulator has to go somewhere, it has
to charge the battery, or the voltage will just get too high...

But, if you have an older battery and it's weak, the battery doesn't do
its part to "sink" the excess current and maybe *that's* why you see
voltage that's a little above spec. Or maybe your voltmeter just isn't
calibrated correctly...

Then there is the excited field alternator, which has a rotating
electromagnetic field in the rotor. Battery voltage goes through a
power transistor to the rotor and through the slip rings and then to
ground. When battery voltage reaches a certain level, the sensing
circuit tells the transistor to shut the excitation current off...

If the sensing circuit has a loose wire or otherwise bad connection,
that connection will have high resistance and it will get hot. The
sensing circuit can't tell the transistor to shut off, so the excited
field alternator puts out too much voltage and the loose connection
gets hotter and it's a positive feedback loop, the hotter the
connection gets, the higher the voltage gets, and on and on and on
until wire insulation and plastic connectors melt and terminals in the
connectors turn black from heat...

Bad connections in a permanent magnet system work the same way, the
regulator never knows when to shut off and burns up wiring. VFR owners
have been known to go through the entire wiring harness and replace as
many crimped terminal connections as possible with directly soldered
connections to get rid of high resistance connections...

 

Is your battery actually overcharging, or is the number you see on a

It's a sealed Absorbed Glass Matt battery. About 4 weeks old.

Both have permanent magnet alternators.

Like I said in the first post, it's a 5 wire system with a 5 wire
regulator (no sensing wire). I'm thinking if I used a 6-wire regulator,
one with a sensing wire, I might have better results?

Correct. I've already replaced some connectors with soldiered
connections, and replaced some crimped connectors with new soldiered
ones.

Thanks,
-Ryan

 

So it needs a little more voltage than a flooded cell battery would
need. No problem, except you are worried about a few tenths of a volt
on your meter and it doesn't agree with the book...

A permanent magnet alternator can easily withstand more volts more than
12 to 15 volts. The problem with having loose or burned up connections
is that voltage can rise up to 70 or 100 volts, and that will burn
holes in the enamel insulation on the stator windings. But 15.3 volts
isn't going to hurt the alternator...

I doubt it. The five-wire regulator just senses voltage between two
pairs of diodes in the 3 phase full wave bridge. As long as all the
connectors are making good contact, that voltage cannot get higher than
the voltage that is charging the battery. So you need good battery,
regulator and stator connections for the zener diode inside the RR to
reach avalanche voltage where it triggers the silicon control rectifier
that shunts the excess voltage and current to ground...

Somebody once said that it took half a dozen crimped connections to get
from some point in the charging system to the battery. That's bad news.
Crimped connections and plastic connectors are there to make parts
replacement quick so the mechanic can make a lot of money of your
electrical miseries. I would replace every crimped connection and plug
on a motorcycle if they were giving me problems...

 

I have emailed the company (WestCo), and they told me it should be
charged at 14.4 - 14.6.

I have a 12g wire going directly from the regulator to the positive
battery cable. No problems with crimped connectors there. Then I have
a 12g ground cable going from the regulator to the frame ground.

So you don't think having 15.1v or so on the battery four 10 hours a
day for 6 days in a row would kill the battery?

The AGM batteries cannot boil off water, they are sealed. I think it
has vents that will break open and cannot be re-closed.

-Ryan

 

The weird thing is I can find several people using GSXR regulators in
other bikes, and they don't note the overvoltage problems that I have.
Here's a guy using a GSXR regulator on an SV650:
http://www.svrider.com/tips/cheapregulator.htm

Could a bad ground on the battery, or some other wierd thing be causing
mine to put out 15.3v? I highly doubt *both* regulators are bad.

-Ryan

 

Do you have an analog voltmeter or a digital voltmeter? Have you had
your voltmeter checked against a calibrated power supply? Check with an
instructor at a local junior college. The electronics lab would have a
calibrated supply and they'd probably be more than happy to check your
meter's accuracy...

Excellent website. He says that the 6th wire controls the "charging
coils". That probably means a 6-wire regulator works only with an
excited field alternator...

causing mine to put out 15.3v?

The "voltage" you read across the battery is the "voltage drop" across
the battery posts only. If you think you have a bad ground cable, check
from the positive post on the battery to a clean point on the engine
and a clean point on the frame, while the engine is running. If you see
a few tenths of a volt more than you saw across the battery posts,
clean the battery cable and the engine ground cable and the place where
the rectifier regulator mounts to and any ground wire coming out of the
RR. That should fix that problem, if it exists at all...

OK. Remove all the fuses from the fuse box that go to the lights. Leave
in whatever fuse you need to let the engine run. Start the engine up,
hook up your voltmeter and rev the engine up to 3K, 4K, 5K...

If the voltage rises up to a peak at whatever voltage and sharply falls
back at some certain RPM and you turn the throttle back down and then
up again and you see the voltage rising and sharply falling off, the
zener diode and the silicon control rectifier inside the RR are working
OK...

If the voltage keeps rising and rising, to say 20 volts, the sensing
circuit inside the RR is probably not working...

Riders with RR problems will frequently note that the voltage doesn't
rise above battery voltage, that it actually goes *down* when the
engine is revved up. In that case, the battery is either toast, or you
have blown out diodes in the RR. If you get 2 blown out diodes, the RR
output will be half of normal...

It would be nice if you had an ammeter, you could see what current is
actually going into the battery...

My Yamaha manual says that, under no load conditions as I have
described (battery in place, but no lights burning) my FZR-1000 should
*regulate* at 14.2 to 14.8 volts @ 3K, an FZR-600 should regulate at
14.3 to 15.3 volts...

My first FZR-1000 maintenance free battery lasted *eight years* with
very little attention. I would hook up a wall blob that I scavenged out
of a trash can, and the blob would trickle charge the battery
at 15 volts or so, and I would go ride the bike and then let it sit for
a few months and blob the battery again before the next ride...

Differences between manufacturer's, so far as electric stuff goes?

There's really not that much difference between manufacturer's
specifications. The Japanese manufacturers are getting all their
electrical stuff from just a few manufacturers and they have to
standardize everything in order to sell what they have available...

The only reason for changing spec's in when something that is really a
lot better comes along. Like the maintenance free battery, which needs
more voltage to charge it than the old flooded cell batteries...

My Yamaha has a Yuasa maintenance-free battery. The charging
instructions for such a battery say that a variable current (adjustable
voltage) charger should be set for 16 or 17 volts, if the battery needs
charging.

It's nice to have an accurate ammeter to hook in series with the
charger. Some VOM's do have an ammeter that goes up to 10 amps to check
the battery charging...

If the current is less than what the sticker on the battery's top
recommends for slow charging, as in the case of a rather discharged
battery, the voltage is raised to 20 to 25 volts! and the battery is
monitored for about 5 minutes. If the current gets up to 1.0 amp, the
voltage is reset to 16 to 17 volts and the battery is charged at that
voltage for 5 or 6 hours...

So, if Yuasa recommends 16 to 17 volts for charging their batteries, I
wouldn't worry too much about "overcharging" your battery...

But, if such fears remain, stick all the fuses back in the fuse box,
and start up your engine, ride the bike for several minutes to recharge
the battery then disconnect the battery + cable *while the engine is
running* and hook your 10 Amp ammeter in series with the battery cable
and the + post and see what reading you get...

Don't try to start the engine with your little ammeter hooked in series
with the + cable, you'll blow up the ammeter...

You should be able to charge your maintenance free battery at about 6
amps for 1 hour. If the battery keeps taking 5 or 6 amps constantly,
that's not good for it, it will get hot and cook...

But, if your battery is already fully charged, it's not going to charge
at 6 amps, it will charge at less amperage...

So what's the battery really getting for charging current? Well, you
could pull the lighting fuses back out while the engine is running and
see what the ammeter does. The silicon control rectifier in the RR unit
is supposed to burn up all the excess current as heat, and the RR
should get hot as hell really quickly if you're running the engine with
the light off...

How do you tell what the state of charge or a battery is, if you can't
stick a hydrometer down into the cells?

A fully charged (90% to 100%) maintenance free battery will read over
12.8 volts after it has been off the charger for 30 minutes...

A 75% charged maintenance free battery will read 12.5 volts after it
has been off the charger for 30 minutes...

A 50% charged maintenance free battery will read 12.35 volts after it
has been off the charger for 30 minutes...

A 25% charged maintenance free battery will read 12.15 volts after it
has been off the charger for 30 minutes...

A maintenance free battery that reads 12.0 volts is pretty much
discharged...

 

Excellent point. I wonder how many problems bikes have can be traced to
faulty test equipment.

 

What happens if you put the original regulator back as a test ?
What voltage do you read then ? Always worth a quick sanity
check of this kind.

Also, it's always worth checking your grounds. With the headlight
on and the engine off (if possible), try reading voltage between
battery negative and frame and between battery negative and engine.
A bad ground will show up as a sizeable voltage difference.

 

I hear you man, but I can only report what I know to be the case. ;-)

I just forked over the cash for Honda's upgraded RR and called it good:
no messing with connectors or extra wires, no (additional) worries about
whether it's designed for the application in question. Granted it's
twice what the RR for an R1 or GSXR costs, but that's the trade. I
figure that I'm only going to buy one of these things (knock wood, do
wire/contact maintenance), so it's not that big of a deal. At the time,
the exchange rate to CA was pretty good so I got it for substantially
less than I could have here in the states. It would cost more now,
though. :-(