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synch
Nomad
Posts: 316
Registered: 9-14-2004
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Mood: wandering...
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Great story corky!
On a vacation to San Fran, I once parked on a steep hill where my Toyota truck had a lot of lean due to the hill's sideways angle. We ate dinner and
went to hit the road but the car wouldn't start. I then noticed that the interior courtesy lights hadn't come on and there appeared to be no
electricity. I got out, opened up the hood, then examined the battery "color" indicators which looked good. Stepping back in, the interior lights
came on, and the truck started.
I later checked the battery fluid level and it was a bit low. When parked on that steeply angled hill, it was possible that the battery plates were
touching enough fluid.
Strangest thing I ever saw....
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Hook
Elite Nomad
Posts: 9006
Registered: 3-13-2004
Location: Sonora
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Mood: Inquisitive
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Diver
Where and how did you manage to shoehorn another battery into the engine compartment of a Ford diesel truck?
Also, have you ever used one of those little emergency jumpstarters you described on your diesel. I have always doubted whether they have the CCA for
it.
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Neal Johns
Super Nomad
Posts: 1687
Registered: 10-31-2002
Location: Lytle Creek, CA
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Mood: In love!
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The gismo that disconnects everything when the battery is low (and when reset, still has enough juice to start the engine) is the Battery Brain,
available at RV stores or from:
www.batterybrain.com/
$40 - $70 depending on the model. I have the $40 one and it works great when you leave the fridge on 12v in the camper or the lights on! Please don't
ask me how I know.
My motto:
Never let a Dragon pass by without pulling its tail!
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El Camote
Senior Nomad
Posts: 514
Registered: 9-7-2003
Location: Above the clouds
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Mood: y Blues
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Aux. batt. questions
Took the fam damily to the beach in the camper last night to watch the almost full moon. Coming home I noticed the dash lights and headlights were
very dim. Stopped for a fill-up and it wouldn't turn over when we went to leave. Got out the cables and did the hermaphroditic thing: Jumped myself
using the fully charged camper battery.
Went out this morning with the voltmeter to check it out. Had to jump it again. Now here's the rub, the aux. batt. is getting a nice fat charge when
the engine is running. The starting batt. is actually discharging at the same time. Even if the starting batt. were caca, wouldn't it show a charge
going in with the engine running? Isn't the way a dual battery system supposed to work is the starting battery gets charged first then the aux.
battery? Could it be possible for one battery to receive a charge without the other? There's no electronics running down the batt., this is a '76
Toyota.
Any ideas???
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bajalou
Ultra Nomad
Posts: 4459
Registered: 3-11-2004
Location: South of the broder
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Do you have a isolater for the camper battery? You should and if you do, it might have failed. (The isolator is to keep the camper from discharging
the truck battery, connecting up only when the alternator is producing.)
No Bad Days
\"Never argue with an idiot. People watching may not be able to tell the difference\"
\"The trouble with doing nothing is - how do I know when I\'m done?\"
Nomad Baja Interactive map
And in the San Felipe area - check out Valle Chico area |
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Sharksbaja
Elite Nomad
Posts: 5814
Registered: 9-7-2004
Location: Newport, Mulege B.C.S.
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Before you get all carried away troubleshooting perhaps you should switch the batts and see if the dead one will charge up. If not, pretty simple
solution, new batt. You may have a warped plate or open in the dead batt.
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thebajarunner
Ultra Nomad
Posts: 3687
Registered: 9-8-2003
Location: Arizona....."Free at last from crumbling Cali
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A little battery trivia
I was standing with Norm Miller (Interstate Batteries chief) on a zero degree day in Indiana in January. I remarked that he would probably sell a lot
of batteries in that cold weather.
He smiled and remarked, "Actually, this cold weather will really deep freeze the batteries but not kill them. The first 100 degree day in July is
when all of these frozen batteries will heat up and die."
He further remarked that the milder the winter, the less summer batteries that self destruct, and vice versa...
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Sharksbaja
Elite Nomad
Posts: 5814
Registered: 9-7-2004
Location: Newport, Mulege B.C.S.
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hmmmmmmmmm! I better consult my old book. Seems to me batteries have a shotened life in the cold if not continually charged.
If a battery sits uncharged in temps lower than 20?F the electrolye will freeze. THen you will need to thaw it first before charging
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thebajarunner
Ultra Nomad
Posts: 3687
Registered: 9-8-2003
Location: Arizona....."Free at last from crumbling Cali
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No disagreement with that Sharks,
just that what triggers the ultimate demise is generally a really hot day, following cold times in winter.
(if you can't thaw it, you can't crank it, obviously)
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Geronimo
Junior Nomad
Posts: 91
Registered: 6-12-2005
Location: Salome Arizona/San Felipe BC Mex
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I did a little research (asked my boss:cool about this bat switching thing that
started this thread. On older non computerized cars it is doable, but you are removing the regulation from the system (in most cases, internally
regulated alts are the exception, do you know what you have?) your alt jumps up to 18v or more, rev the motor and you could see 110v. On a post 96'
(OBDII) cars I would expect catastrophic computer failure. OBDII cars use 5v reference volts to all sensors on the motor, send 12 volts down those
wires and a tow to the border and a huge repair bill are in order. We need to be careful with modern cars, we are using them outside of what they
were designed to do (go to the mall?) and are constantly risking getting stranded. I bought a box; carry charged Optima with me. Oh and remember,
especially on GM vehicles, if you have the bat disconnected your system will have to relearn it parameters and could run bad for 50 miles or so, could
be bad if you have a rocky climb out of camp.
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Sharksbaja
Elite Nomad
Posts: 5814
Registered: 9-7-2004
Location: Newport, Mulege B.C.S.
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I confess!
I guess being an old school mechanic I was lucky I never tried my technique on the wrong vehicle. After reading a couple replies I was ever so
curious. Here is a good overview of a cars voltage generating system.
Taught me a few things:
Generators and Charging Systems
Part 1 of 3
By Vince Fischelli
In the old days, an alternator replaced the old-style generator, which was used primarily to keep a battery charged enough to crank an engine and
keep the headlights bright enough to see at night. The alternator proved to be quite an improvement over the old-style generator, which needed new
brushes every 15,000 to 20,000 miles. Generator repair was such a significant market that shops whose only business was to rebuild generators and
starter motors flourished. The real reason behind their success in the past was that the average auto ?mechanic? was less than competent at diagnosing
?electrical? problems and preferred to leave that to ?experts? while they focused primarily on mechanical repairs and tuneups. Many mechanical guys
seemed to be unable to fathom that ?electrical stuff.?
I'll never forget this old-timer who had worked on cars since he was old enough to pick up a wrench. He had never been to school and he worked
barefoot on his dirt-floor, one-stall, wood-frame garage next to his house. The cars were lined up every day because he was good at it and he was
honest. Sometimes he even took pies in payment if the customer didn't have enough money. We kids used to stop by his house and listen to him bang and
grunt as he worked away. It was a mysterious place to kids, with the dirtiest dirt I ever saw. It was a mixture of oil, grease and discarded chewing
tobacco drippings. We knew not to walk close to the big tree next to his garage because our feet would sink into the ground and come out all black and
covered with smelly engine oil. I always waited for him to grind some metal on his grinder. The beautiful yellow/orange spray of glowing sparks always
fascinated me. It still does to this day.
Occasionally he would engage us kids in conversation as if to confirm his diagnosis with someone else who wouldn't tell him he was wrong. One day I
watched him check a ?newfangled gadget? that replaced the generator by holding a screwdriver next to it. He explained that if the alternator pulled in
on the screwdriver the alternator was ?puttin' out.? I was quite impressed with his knowledge but I was only 11. Then again, if the alternator pulled
in on a screwdriver, kept the battery from going dead and made the headlights bright enough, what other test did you need?
Have times changed now! The alternator not only keeps a battery charged and the headlights bright at night but now it powers onboard computers. What
would that old-timer think about that? The complications of today's vehicle electrical systems demand more advanced testing than using a screwdriver
to check the strength of a magnetic field. No longer can we leave electrical diagnosis and repair to others. No longer can we expect cars to be
repaired by mechanics with no education. Times have changed a lot of things in the automotive and truck repair industries.
Let's see what we can learn about alternators in this three-part series. The term ?alternator? to describe what we have been calling an alternator is
now obsolete. We are now (since the 1996 model year) to call them GENERATORS. The name change more accurately describes what an alternator (oops - a
generator) - does. (Sorry, old habits are hard to break.)
It is customary to identify a voltage source by the type of voltage it provides, AC or DC, and not by the way the output voltage is developed. A true
alternator produces AC voltage at its output, whose frequency is dependent on speed of rotation of an electrically charged coil inside a stationary
coil. Well, that kind of sounds like an alternator doesn't it? What's the problem? What we get from what we used to call an ?alternator? is DC
voltage, not AC. The term ?alternator? doesn't fit. How could we have been so careless all these years? It should have been called a generator all
along. Well, frankly I couldn't ?care-less? what we called it as long as I could repair it. Yes, but we have all erred and caused great confusion
within the industry ... lo, all these many years, say the ?experts.? We must change ... and yes ... we will. It is a GENERATOR. 'Nuff said? Let's get
serious about generators with this three-part series of articles: How they work (Part 1), how to test generators and the charging system correctly
(Part 2), and how NOT to test a generator and the charging system (Part 3).
How Diodes Work
Generators need solid-state diodes to do their job. We know that a diode lets current flow in one direction but not the other. But, how does a diode
respond to voltage? Let's look at both current and voltage with respect to the diode symbol shown in Figure 1.
Fig 1
The diode lets electrons pass through in the opposite direction the diode's arrow is pointing. For this to happen, a diode must be forward biased.
That means the diode anode is more positive than the diode cathode. Forward bias allows electrons to flow through the diode. Without forward bias
there is no diode current. If a diode gets reverse bias at its two leads, the opposite polarity of forward bias, the diode is cut off and electrons
cannot pass through. This explains how current flows through a diode, which is necessary to understand how a diode in a generator makes it ?generate?
DC voltage and current. Without diodes, generators could not generate electricity. Let's talk about a generator. It's quite a story.
Generators
A generator contains several major components. The voltage regulator controls the amount of electrical energy produced. The rotor is a large spinning
coil inside the generator. The outer ring around the spinning rotor contains at least three stationary coils called stator windings. When three stator
coils are present the generator is a three-phase system. Some manufacturers use four stator windings and they are four-phase systems. The more phases
in the generator, the more efficient it is and also, the more costly to build. Three-phase generator systems are the most common.
For a generator to generate electricity it must be electrically excited. It needs a battery to get going. Fortunately, every vehicle has a cranking
battery. Battery energy is used to kick off the generator once the engine begins to run. Some techs have tried to take a weak or dead battery and
place it in a car with the engine running to recharge the battery. Good luck because you will probably need it. First of all, NEVER - I say, NEVER - I
say again, NEVER - disconnect a battery cable while the engine is running. The battery acts as a voltage stabilizer to help the generator keep its
head. Take the battery away by simply disconnecting one of the battery cables and the generator loses its best friend. It then may go crazy and
produce voltage spikes and a major energy dump into the generator and the electrical system, destroying the generator and a lot of electronics in the
car. 'Nuff said? The other problem with putting a dead battery in a running engine (if you don't fry the generator and the car's electronics) is that
the generator is looking for a little energy from the battery to get started charging. Dead batteries are notorious for having no ?juice.? You can't
start off a generator with nothing. It'll just sit there and spin (oh well, we try, don't we?). It is true, however, that some of the first
?alternators? were able to charge a partially discharged battery because they were well built and could take the abuse. That is not true of today's
generators.
Let's take a walk through the alternator (oops, there I go again; it's a generator, dummy). We'll look at how the component parts of an alt? ... err,
a generator ... work together to charge the battery ... and ... electrically power the vehicle. That's right! The generator has two functions in a
vehicle. The generator provides the electrical energy to operate the vehicle when the engine is running besides charging the battery at the same time.
This makes the generator's performance during engine run very important. It ensures that the computer-controlled engine gets the power it needs to
function properly to maximize fuel economy and minimize pollution. The battery is actually ?off-line? when the generator is generating. If the
generator cannot generate electricity, the battery takes over and runs the vehicle until the battery runs down. Then you are walking.
Figure 2 shows the rotor and stator windings in schematic diagram form. The stator winding is a delta connection because the three windings are
connected in series to form a triangle like the Greek letter delta. Another stator winding configuration is called a ?Y? (wye) winding because the
three stator coils are connected to a central connection point. The name for this stator configuration looks like the letter Y.
Fig 2
Transistor Q1 is a power transistor located in the voltage regulator to control rotor winding current. Current flows up through the generator ground,
through Q1 (emitter to collector) and through the rotor winding to B+. If you ever held a screwdriver next to a running generator you have felt the
screwdriver being attracted by the intense electromagnet of the rotor inside the generator.
The rotor rotates within the delta stator winding to induce energy into the stator windings, using the principle of electromagnetic induction. The
induced energy in the stator winding is a traditional AC sine wave with both a positive peak and a negative peak occurring each 360-degree cycle. The
sine wave describes the voltage change and the current change in the stator winding. Sine wave stator voltage constantly changes amplitude going
through a positive peak down through zero volts to a negative peak then back up through zero volts to a positive peak, etc., ... over and over again.
The sine wave frequency depends on rotor rpm.
Sine wave stator current periodically changes direction. Stator current follows behind the stator voltage peaks because the inductance of the rotor
coil opposes changes in current. That's what a coil normally does. During the positive current peak, the (+ alternation) portion of the sine wave,
stator current flows in one direction to a peak. Then, it falls to zero and reverses direction during the negative, or - alternation, rising to
maximum in the opposite direction at the negative peak. Then stator current falls to zero again, momentarily stopping and reversing direction. Current
rises to a maximum peak current in the opposite direction during the + alternation, etc. ... over and over again. The question to be answered is: What
does the stator do with all the sine wave energy induced into it?
The sine waves are presented to the positive and negative diode assembly or diode bridge shown in Figure 3. There are three so-called positive diodes
because they connect to the positive terminal of the battery (B+). There are three so-called negative diodes because they are connected to ground,
which is also the negative terminal of the battery (B-). The positive and negative diodes actually are the same type of diodes but are named after the
battery terminal to which they are connected. A positive and a negative diode forms a series circuit network between B+ and B-.
At the common connection point between the two diodes is a wire from one of the stator windings. The stator's sine wave energy is connected to the
common connection point between the two diodes. The job of the positive and negative diodes is to rectify the AC. Rectify means to change the AC to DC
(direct current). The DC is then used to charge the battery and provide a DC energy source to power all vehicle electrical circuits. All the voltage
energy put into the diode bridge drives the current through the vehicle electrical system. All DC current that runs the vehicle passes through the
diode bridge. The diode bridge generates a lot of heat from all the hard work it must perform. If the heat is not dissipated adequately, the diode
bridge will burn up and the generator dies - no charging voltage, no charging current.
Here is where diode knowledge comes in handy. The positive and negative diodes convert the stator AC to DC. Let's focus on only one phase or one
positive and negative diode network for this explanation. When the stator voltage sine wave swings positive, the positive diode turns ON (forward
biased) and the negative diode turns OFF (reversed biased). Refer to Figure 1 again for the polarity of voltage that forward biases a diode. The
positive energy in the + alternation of the sine wave pulls electrons out of the positive terminal of the battery and through the positive diode
flowing against the arrow. During this time the negative diode is reversed biased. Then the negative energy in the - alternation of the sine wave
swings to a negative peak, pushing electrons into the negative terminal of the battery and through the negative diode flowing against the arrow.
During this time the positive diode is reversed biased.
Each positive and negative diode network ?alternately? rectifies its sine wave from its stator winding following a rotating order of 1, 2, 3 then 1,
2, 3, etc. A continuous stream of sine waves are rectified so that the current produced by the sine waves is a constant pulsating DC. Figure 4 shows
the resultant ?ripple? pattern riding on the DC charging voltage. Energy is directed by the diode bridge in the correct polarity to charge the battery
in a continuously charging current through the battery being propelled by the charging voltage (also rectified by the diode bridge). The energy in the
+ alternation is directed to the positive post and the energy in the - alternation is directed to the negative post.
Electrons are pushed out of the generator's negative terminal and sucked into the generator's positive terminal in a continuous motion. At no time
does any diode network stop contributing its share of electrical energy to charge the battery or provide energy to the vehicle. Each phase of the
generator simply ?peaks? in numerical order as long as the rotor is energized and turning. The end result is a pulsating DC voltage and current source
at the generator terminals.
The purpose of the diode trio
The diode trio has a unique function in the generator. Notice that the three cathodes in the diode trio are tied together and go to the rotor
winding's B+ side. The three anodes are connected to one of the three diode networks where the stator sine wave is applied. What's the reason? This is
especially interesting since some generators do not use a diode trio; therefore, a diode trio isn't always necessary for a generator to generate.
The advantage of using a diode trio is most evident when the diode trio fails. The generator light comes ON at idle and goes OFF when rpm increases at
acceleration. The purpose of the diode trio is to increase generator output at idle since at low rpms a generator may not turn fast enough to produce
the energy needed to charge the battery and operate the electrical system. Increased generator output at idle is accomplished by the diode trio taking
some of the stator sine wave energy, rectifying it to DC and sending it to the rotor winding for increased excitation during low rpm (idle)
conditions. By applying an increased amount of B+ to the voltage side of the rotor winding, more current is drawn through the rotor to increase
excitation. During times of high rpm the diode trio isn't needed but continues to contribute to the overall generating efficiency of the generator.
I'm still not convinced however bout switchin' but it seems the older the
better in this case
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The squarecircle
Nomad
Posts: 173
Registered: 11-28-2004
Location: El Cajon
Member Is Offline
Mood: 'Baja Feeling'
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Greetings Sharky: >>>>>> Nice find and read, dude!!!! Now, I will closely scrutinize the following 2 parts of this 3 part
script to observe the verisimilitude of this wisdom yet to come. This information will surely help extract me from a tight jam when (i.e. flat
battery) a FIELD FIX is required out in the middle of no-where and some where else deep in Baja. >>>> Kindest Regards, sq.
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Spyderman
Nomad
Posts: 111
Registered: 10-12-2005
Member Is Offline
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Great story, Corky
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Spyderman
Nomad
Posts: 111
Registered: 10-12-2005
Member Is Offline
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There is one other thing about jump starting or switching batteries. Always be careful, fan the top of the battery a bit because the gases from the
battery can explode and all it takes is a little spark.
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