More battery/electrical drama

This is about a 1993 CBR600 F2.

So after putting in a new battery and riding the bike around for the last
week or so, I invested in a battery charger. I actually bought a tender,
but the stupid seller sent me the wrong, bigass charger with clamps, etc.

I hooked up the charger up to my old, dead battery. It charged up real
quick and was stated to be full fast. Surface charge, I guess. I ran it
down with a turn signal connected to the battery. Reconnect the charger.
This time it takes a long time to charge back up. Good. I set it aside and
go to the bike, get to the new battery, and top off the charge. I notice a
loose quick-connector (yay!) and squeeze it closed. So I'm wondering how
the old battery would do.... I throw it in the bike, turn the kill switch to
on, and crank it up to see how well it cranks for 10 cycles or so.

It cranks up strong with the old, recharged battery... lights look strong.
I turn the kill switch off and start up the bike. I stare at the neutral
light... no flickering, good. Next, I bring down the laptop with the Honda
PDF. I do the current leak test. 0.00amps. Then I check the voltage at
the battery across the RPM range. It looks like at <1300rpm the voltage
drops below battery voltage (12.7V). At >1700, the voltages stay within
specced range (13.3V-15.5V). So regulator/rectifier should be okay, right?

I find the RR and check the continuity where it should be. However, I check
the red/white and ground voltage, which should match battery voltage, and it
doesn't work. I get 0V. Not sure if this is okay, but the RR does have the
words CBR 95 chalked on it. I'm wondering if this was a replaced RR because
the original one went bad.

So all in all, I gave myself an electrics lesson and was able to check some
electrics on the bike. Any thoughts on what I've revealed?

 

Yeah, you've revealed that you know a lot more about
it than me.

Gary

 

Sounds like everything's fine with the bike. Put the new battery in
there and enjoy it.

btw, I found the designation of my instrument lamps (off a '94 VFR750F),
in case you or someone else needs it. They use: T3 1/4 miniature lamp,
658 (158 or 194 would also probably work). The 'T3 1/4' designates the
lamp shape and size. The 3-digit numbers designate lamp wattage. The 658
is closest to what I've got, but I think that I've got one 194 in the
bike right now and it works fine.

--
Later,
John



'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.

 

Yeah, well the strategy of the new "smart" chargers seems to be to sell
the charger to somebody who knows *nothing* about batteries and
chargers. The so called "smart" charger will shut off if it senses that
the battery isn't charging or if it's sending to much current to the
battery and might damage itself.

What you really need to charge a dead battery is a *variable voltage*
charger that you can crank up to about 20 to 25 volts and observe an
ammeter for a minute. That definitely wakes up a dead battery.

I told you before once that you could take two car batteries and hook
them in series to get 24 volts to wake up a dead battery. Just put a 1
amp amp in series with the two batteries and wait five minutes to see
if the fuse blows. If it does, you can start charging the dead battery
with a real charger that has a big rheostat on the box.

If it starts charging within a minute or two, you then reduce the
voltage to 16 or 17 volts and monitor the charge rate. After a few
minutes, you can adjust the voltage to charge the battery slowly, at
about 1 amp for 6 to 8 hours.

Yeah, well, you just *deep-cycled* the battery. Lead-acid batteries do
not like to be deep cycled any more than they like to be quick charged.
They shed lead from the plates and they sulfate if you don't recharge
the battery.

Yup.I've seen that happen many times. It's amazing how riders won't
check out the simplest possible problems, like loose connection.

Bzzzzt! The starter isn't designed to keep starting the engine over and
over and over.
Although it only dissipates about 500 watts, that 500 watts is trapped
inside the starter and it takes a while to dissipate the heat. You can
burn up a very expensive starter if you overheat it. You should only
crank the engine for about 5 seconds, give the starter about 20 seconds
to cool and then try again for 5 seconds.

A better way to do a capacity test on a battery is to disconnect it
from the motorcycle and hook a known wattage light bulb across the
terminals and observe the battery voltage. An 8 ampere hour battery
will supply 8 amperes for 1 hour without the voltage dropping below 12
volts. If it only takes half an hour for the voltage to decay below 12
volts, the battery is approximately half used up.

I dunno. The question you should ask is *does the regulator CYCLE
voltage*, from high to low when you increase the engine RPM past 3000
RPM to 5000 or 6000, and does it CYCLE back to high voltage when you
decrease the RPM back to around 3000 RPM

There are two basic types of alternators, excited field and permanent
magnet.

The excited field type of alternator will take power from the battery
and run it through a transistor with a voltage sensing circuit. When
the battery voltage rises too high
the transistor will shut off the excitation current to the alternator
field and you will see a sharp voltage drop as the transistor stops
conducting.

But that type of regulator CYCLES from high to low and back.

The other type of alternator is a permanent magnet type. When the
voltage rises too high, the voltage sensor causes a silicon control
rectifier to *shunt* excess voltage to ground, burning the excess power
up by changing it to heat.

Again, the question is, *does the regulator CYCLE from high to low and
back, over and over and over?"

It's entirely possible for the voltage sensing circuit to fail and the
regulator never cycles, it just allows the voltage to stay too high and
the wiring harness connectors eventually melt.

In the realm of shunt type regulators for permanent magnet alternators,
there are FIVE wire regulators that take three AC phases and convert
them to DC, and there are SIX wire regulators that have an extra wire
that senses battery voltage at a remote location.

The six wire regulator is known for causing charging system problems.

So, count your wires, and if you have a sixth, sensing wire, relocate
to so it senses battery voltage, not the voltage drop across the wire
harness.

 

I've actually left the old one in to experiment... I'm curious to know if
the charge was all that was needed.

Thanks very much! I'll look into it and see what I can find.

 

This is the thing... I believe that this charger might actually have some
real function (Schumacher SC-6000A) because it seems to put the battery
under load for a couple of seconds to measure some current/voltage drop, and
then from there determines a percentage capacity rating. Then it takes off
the load and begins charging.

Hmm... When I turned it to the 10-30A range on the charger, the voltage
bumped up to around 16V. I only did it for a couple of seconds, though.

You mean like the 10/30A charging function that's on the charger?

Hmm... I tended to leave it on 2A because that's what the manual said. I
figured I'd rather not acidify or blow up things.

Oops, I didn't put enough detail. I ran the battery down a couple of volts
in several minutes with just one 18W turn signal. The charger manual said
to turn on some accessories to burn off the surface charge so that real
charging could occur. It seems to have worked.

Oops, I didn't mean 10 cycles as in 10 starting cycles. I meant 10 cycles
as in 10 crank revolutions. With the kill switch engaged.

Yes, yes... it would have been just dumb to run a starter that long.

Interesting... I always forget the simple math in electrics.

Yep, that's exactly what I saw. At around 2500, the voltage dropped.

I think this is what the CBR is. I mean, it's called a regulator/rectifier.

No connectors looked burnt or yellowed or browned or brittle...

Hmm... just three yellows, one red/white, one green ground.

This is what I don't get. If the frame is ground, how come the frame
doesn't build up excess charge and statically shock me from time to time?
Or if I'm connected to the frame, and I touch the ground, isn't the frame
ground and earth ground not at the same voltage since the tires insulate?

Thanks for the details and charging lessons!

 

Well, be careful with that thing, when you're charging a motorcycle
battery. It's like using a sledge hammer when you really need a tack
hammer. Your battery is probably has 8 or 10 ampere hour capacity and
car batteries often have 50 to 60 ampere hour capacity.

The charger tries to keep the current the same throughout the charging
cycle. It probably has a multiple tap transformer inside it that steps
120 volts AC down to 14,
16, and 18 volts, with a voltage sensing circuit that changes from the
highest voltage
tap to the lowest voltage tap, but it has no way of knowing that the
battery it's charging isn't a car battery.

So heat can build up very quickly, warping the battery's plates and
causing them to shed lead. Another possibilty is that hydrogen gas
pressure can build up too quickly in the case of an unvented battery.

Charging your battery at 10 amps is still about 3 times as much current
as you want to put into that battery, and, when you think about the
HEAT you're putting into it, that's a function of the *square* of the
current.

So, charging a battery at the correct 3.5 amp rate would be putting
about 12 watts into the battery, but charging at the 10 amp rate would
be like putting 100 watts into it.

You know you can't hold your hand on a 100 watt light bulb that's lit,
what's a little battery supposed to do with 100 watts going into it?
All it can do is boil the electrolyte.

That's still twice the recommended trickle charge rate. Watch for heat
buildup and excessive gassing. Boiling electrolyte is bad news.

Heat causes the death of motorcycle batteries. They live in a terribly
hostile environment under the seat, taking all that trapped heat from
the engine. And, if you put too much heat into a battery so the
temperature inside it gets up around 130 degrees, it's going to die in
short order.

The three yellows are the three AC phases coming from the allternator.
The red/white is probably the positive DC wire to the battery. You
should be able to measure 12 to 16 volts DC on that wire when the
engine is running. The green wire is probably a ground wire.

The function of the chassis ground has nothing to do with static
electricity. But, if you wash your motorcycle and touch the positive
battery terminal with a wet hand, while standing barefoot in the puddle
of water your motorcycle is parked in, you might feel a slight tickle
of electrical current passing through your body.

The term "ground" or "earth" refers to the use of the frame as a
"return" circuit to reduce the number of wires needed to complete a
circuit.

The convention is that current flows from the positve terminal of the
battery, through the electrical loads, to the chassis and back to the
negative terminal of the battery.

Physicists will claim that the flow of current is actually exactly
opposite, and that the chassis ground makes a large reservoir of
available electrons, reducing the total circuit resistance, compared to
a circuit that needs both power and return wires.

You may have noticed that electrical power cords on household
appliances get hot. That's because of the tiny resistance of the copper
wires.

Electrical engineers have standards for how much current a wire of any
given size can safely carry in free air, and the current is reduced if
the wires are bundled together in a harness.

If your motorcycle didn't use a chassis ground, the extra return wires
would double the size of the wire harness and there would be twice as
much heat radiated from all the wires.

 

Sound advice, on both counts.

 

My roommate explained it to me right after I posted.

Ah, it all makes sense now... it's like the vena cava.