Topic: Charging and Urban Myths

[edbikerii]

As for rejuvenating auto/motorcycle batteries vs. giant train batteries, I did some research, and it seems that there are physical differences both within the batteries and the charging systems.

Once an automotive battery will no longer pass a load test, it is a goner, and cannot be rejuvenated.

[csendker]

But doesn't the rectifier act as kind of a check valve?  I understand that if the charging voltage is less then the battery voltage there would be a depletion (but didn't know that charged is 12.6V, thanks...), but if there's a 'check valve', that would effectively stop it.  I didn't think a rectifier could work backwards, but then again, I don't know how the thing really works either.

The bike's electrical system never really 'sees' the 14.5V, does it?  I would think only the battery would get that voltage, and feed the bike with whatever the terminal voltage is.  However, the 'in' and 'out' are both fed to the same terminal post, so maybe it does?  If so, then couldn't you see the regulator kick back & forth between charging and maintenance by watching the headlight fluctuate between 14.5 & 12.whatever?  Or is the incoming charge overwhelmed by the battery capacity, in effect acting as a dampening chamber?

Or is it that little backfeed to the field coil sucking up the juice?

[csendker]

auto/motorcycle batteries vs. giant train batteries

Yes, but I would still like to see a 300# battery strapped to a bike sometime.   

[edbikerii]

That darned GoldWing battery weighs nearly 20 lbs., I'd say.  I guess that's not good enough.  I'm quite sure the luggage on that bike could hold a 300lb. battery no problem.

auto/motorcycle batteries vs. giant train batteries

Yes, but I would still like to see a 300# battery strapped to a bike sometime.   

[Partsbiker]

Funny story and not altogether too unrelated.
A few years ago I was helping a buddy of mine rebuild a mitsu eclipse engine.
I had my car parked next to the mitsu with my hood open.
Now I'm a fairly smart person and when I buy batteries I dont go for dimensions, I select my new battery based on amperage ratings. So that leaves me with the ability to get a dual post type battery, side and top mount, for versatility. My car uses side mounts for the stock electrical system but since I had a few extra goodies like new head unit for stereo and a few lighted gauges on the inside I decided to just slap a couple of top-mount battery ends on the battery and run a seperate hot and ground 16gauge wire circuit inside my car.

Well my buddy walks over to my car and sees the top mounts and DOESNT see the sides and yells " Johnson...!!! " (my last name) and just points at the top mounts. I told him i had a special battery made that puts out 10,000 VDC so i can start the car on 16gauge starter cables. Had him going on that for about 3 months 

[TwoTired]

But doesn't the rectifier act as kind of a check valve?  

Yes, it is a check valve for current.
Back up.

The battery is a DC (Direct Current) creature.  It likes to take in current in a constant fashion, and it doles it out the same way.
  The current in an alternator is constantly changing direction (Alternating Current) depending on which magnetic pole it is associated with at a given moment moment, and this changes several times in a rotation.

The rectifier blocks battery current from depleting into the stator coils.  More importantly, when the alternator makes more voltage than the battery has, the rectifier allows only the current polarity acceptable to the battery, to pass through it.

Voltage is the potential to do work.  Current is what happens when it its working.

12.6 V is a charged and resting voltage for a good battery.  Depeletion (or on its way to depletion) is below that voltage.  A battery that is accepting a charge can and should be above that voltage.

Would it confuse you to know that a battery doesn't actually store electricity?  It converts electricity into a chemical reaction.  This then produces electricity when the chemical reaction is reversed.

The bike's electrical system CAN see 14.5V only when the battery has been charged to that level.  The electrical voltage level of the bike IS the battery voltage.  The battery is normally slow to change it's level, and the charging system can only persuade it to reverse the chemical reaction.  It cannot demand it.  There is much more conversion power in the battery than the alternator can ever hope to make in an instantaneous time period.
 If the voltage regulator is doing its job, it monitors the battery for signs of overcharge.  When this occurs, the regulator tells the alternator to not make as much power (lowers the Field voltage).  The alternator output is then usually below the usage level of the bike electricals, so the battery depletes and the voltage falls.  The Regulator sees this and say's "OH my GOD the battery isn't full" and applies the whip to the alternator in the form of more voltage to the Alternator field coil.  The cycle continues at a frequency governed by the electrical load, the power or rotational speed of the alternator rotor, and the conversion capacity of the battery.

You can never see this with the naked eye.  Tools must be used to interpret voltage levels.  These tools are not absolute.  Some average, some sample, some have display update frequencies that beat against the Voltage Reg reaction frequencies.  Few of us have oscilloscopes to monitor the goings on visually.  But, that's okay. You can get the gist of what is going on with simple DMM and VOM measurements.  And a good battery should act as a huge capacitor to filter/iron out rapid voltage oscillations at the battery.  This is why the alternator connection should be made as close to the battery terminals as it possible.

 If so, then couldn't you see the regulator kick back & forth between charging and maintenance by watching the headlight fluctuate between 14.5 & 12.whatever?  Or is the incoming charge overwhelmed by the battery capacity, in effect acting as a dampening chamber?

That's a descent enough conceptual description.  But, you probably shouldn't teach that way.  
You can see the effect of the regulator working on the White wires from the regulator, provided the frequency it is operating at is within the display range of your instrumentation.  There may also be some small ripple currents wandering about the bike wiring, too, if you know what to look for.

Hope this helps,

[333]

But doesn't the rectifier act as kind of a check valve?  I understand that if the charging voltage is less then the battery voltage there would be a depletion (but didn't know that charged is 12.6V, thanks...), but if there's a 'check valve', that would effectively stop it.  I didn't think a rectifier could work backwards, but then again, I don't know how the thing really works either.

The bike's electrical system never really 'sees' the 14.5V, does it?  I would think only the battery would get that voltage, and feed the bike with whatever the terminal voltage is.  However, the 'in' and 'out' are both fed to the same terminal post, so maybe it does?  If so, then couldn't you see the regulator kick back & forth between charging and maintenance by watching the headlight fluctuate between 14.5 & 12.whatever?  Or is the incoming charge overwhelmed by the battery capacity, in effect acting as a dampening chamber?

Or is it that little backfeed to the field coil sucking up the juice?

The rectifier just converts AC to DC.  The alternator produces AC, you need DC to charge.  The regulator is the check valve.  Technically speaking, your light bulbs would last longer if they received AC, but there is no simple way of supplying half you bike with AC and the other half with DC.

[csendker]

Would it confuse you to know that a battery doesn't actually store electricity?  It converts electricity into a chemical reaction.  This then produces electricity when the chemical reaction is reversed.

Ok, I never thought about batteries this way, but I get it and it does make sense.  Better batteries likely have much more efficient conversion rates rather than larger 'storage' capacities.

The battery is normally slow to change it's level, and the charging system can only persuade it to reverse the chemical reaction.  It cannot demand it.  There is much more conversion power in the battery than the alternator can ever hope to make in an instantaneous time period.

So if the bike is primarily powered by the battery (chemical reacting to produce electricity) then how does it simultaneously get charged (electricity incoming causing a reverse chemical reaction)?  Or, does the power produced by the alternator pass BY the battery on it's way to power the bike, while the potential at the battery terminal determines if the battery is charging or discharging?  I suppose this would be the case if the battery potential (V) overwhelms the alternator potential (V), making it the dominent voltage decision maker.

The rectifier just converts AC to DC.  The alternator produces AC, you need DC to charge.  The regulator is the check valve.

Confusion strikes.      In the mechanical world that I live, those little arrow symbols in the rectifier are check valves of sorts.  I thought they were basically switches that only allow the current to pass in one direction, thus converting alternating (two directions) to direct (one direction).  In any event, the power can't go backwards through the rectifier and discharge in the alternator.  On the other hand, if the voltage gets too high, then the regulator senses this and switches, thus pumping power into the field coil which effectively reduces the alternator output.  The main power to the bike doesn't really pass through the regulator, but BY the regulator.  It regulates the voltage supplied by the alternator.

Dragging this potential thread hijack (a voltage hijack??) back to the original issue, I run my bike w/a halogen headlight on all the time.  If I don't, Mr. Officer will have a chat with me, something about a law being broken.  At the risk of bad luck, I don't have to charge my battery at all during the season, and I don't seem to have any degredation that's noticible.  So it's possible that I'm slowly killing my battery and just haven't noticed it yet, or maybe I'm just making it with the power management.  I'm slooooooly cleaning up all the terminals and connectors to help reduce the harness resistance (resistance = lower voltage...)  I also swapped my taillight out to a LED unit.  It's on full time, so that's a real savings (as opposed to say indicator lights).  I would occassionaly (rarely) blow my main fuse before the taillight swap, so I must have been right on the line, or slightly over.  It seems OK since the switch, so I'm guessing I may have stepped back from the line.

[nickjtc]

D'ohhhhhhhh. My brain hurts. Think I'll step over to the boob thread for some light relief.

[edbikerii]

if the voltage gets too high, then the regulator senses this and switches, thus pumping power into the field coil which effectively reduces the alternator output

You've got it right on, except for the statement above.  It is exactly the opposite.  The alternator has no magnetic field until the regulator pumps power into the field coils (hence their name).  When there is power on the field coils, they become an electromagnet, thus causing current to be generated in the stator and produce output from the alternator.  In this system power only goes to the field coils when the regulator senses that the current is low, so no excess voltage is created.

Permanent magnet alternator systems are very different.  I'm not too familiar with their internal workings, but I assume that their regulators either dissipate the excess voltage as heat (shunt it into a big resistor?), or disconnect the stator circuit when more voltage is not needed.

[TwoTired]

So if the bike is primarily powered by the battery (chemical reacting to produce electricity) then how does it simultaneously get charged (electricity incoming causing a reverse chemical reaction)?  Or, does the power produced by the alternator pass BY the battery on it's way to power the bike, while the potential at the battery terminal determines if the battery is charging or discharging?  I suppose this would be the case if the battery potential (V) overwhelms the alternator potential (V), making it the dominent voltage decision maker.

You can think of the battery as a reservoir and the bike electricals as the discharge pipe at the bottom.  The alternator is all the snow in the mountains, and the Voltage regulator controls how much of the snow melts.  The Vreg makes its decisions based on the level of the reservoir.  At engine idle the snow melt is sparse and the reservoir depletes.  Rev the engine and it's like fresh snow melt in the mountains.

The battery accepts power whenever it is presented a current source with a voltage potential higher than it's present state.  If the load presented by the bike exceeds the delivery capacity of the charging system, the bike drains the battery.  When the charging system makes more power available than the bike uses, the excess goes to refilling the battery, unless the battery is full, which is when the Vreg should force the alternator to make less power.  The bike presents more or less a fixed load (barring high beam selection selection changes, turn signals, horn) whenever it is running.

Cheers,

[neil young]

D'ohhhhhhhh. My brain hurts. Think I'll step over to the boob thread for some light relief.

no kidding.i think i will join you

[csendker]

The alternator has no magnetic field until the regulator pumps power into the field coils (hence their name).

Ah-ha! The light bulb goes on. The field coil gets the alternator working, much like a permanent magnet would if these had them.  Thus the "you need a battery to get these started, even with the kicker" concept.  So the regulator senses the voltage and adjusts the field coil power DOWN to LOWER the alternator output.

I can't recall where the heck I got that diagram, but I noticed it's "Mode 1 - Low Battery Charge", insinuating there's others out there with different power flow arrows for different scenarios.  I'll have to look for the rest.

D'ohhhhhhhh. My brain hurts. Think I'll step over to the boob thread for some light relief.

Either that or we need to set up a fund just to make sure seaweb NEVER stops buying stuff from morons.  The Bounty Hunter threads are worth their weight in gold just for the pure entertainment value alone.  I never want to piss off any of these guys.

[bryanj]

That diagram, plus the other two are on the site somewhere 'cos i sent em in. They explain the 3 states of regulator working as i put in earlier.
 i still have the scans and will email them on request, form an orderly queue now, but you will need broadband as they aint small, and if i shrink em they dont come out good.

[CrisPDuk]

You can think of the battery as a reservoir and the bike electricals as the discharge pipe at the bottom.  The alternator is all the snow in the mountains, and the Voltage regulator controls how much of the snow melts.  The Vreg makes its decisions based on the level of the reservoir.  At engine idle the snow melt is sparse and the reservoir depletes.  Rev the engine and it's like fresh snow melt in the mountains.

That is one of the best analogies for an automotive charging system I've ever seen

Are you a teacher TT?

[NH_CB550F]

Remember how all old vehicles used Generators and how we now use only alternators ?

 Generators only created power for half the crank rotation. Since the magnets repulse on the turn of the crank.

The Alternator capitalizes on this by flipping the opposite pole power by using a Rectifier or Diode.
 Since the advent of the diode, which only allows current to flow in one direction we can now utilize both halfs or 360 degrees of the rotation into power.

That's what all those triangular looking things are in your circuit diagram. In fact the point is oriented in the direction of current flow. Its called a diode bridge, our rectifier

The Alternator rotates 360 degrees creating "alternating" pulses of energy positive and negative or Alternating Current which is self cancelling as far as a battery is concerned. The diode bridge or "Rectifier" rectifies it into DC so the battery now likes it.

The regulator "regulates" the amount of juice flowing into the battery by providing a constant voltage across the battery as the alternator generates more/less energy as the crank speed changes.

In other words...
Ohms law V = RI requires higher voltage to the battery in order for current to flow into it and charge. The regulator does this by regulating the voltage coming from the alternator and it's resulting current flowing into the battery, Hence the term "Regulator", .

The battery resistance is a constant so by increasing and regulating the input voltage we increase the current flowing into the battery.
The regulator limits this to 14.4V to limit the amount of current flowing into the battery in order to not damage it.

So as far as the battery is concerned, the regulator looks like another battery but at 14.4 volts.

Since voltage, like water flows downhill, a higher voltage 14.4V will flow current to the lower 12 volts of the battery and charge it.

I hope this makes sense.

Todd

[TwoTired]

The regulator "regulates" the amount of juice flowing into the battery by providing a constant voltage across the battery as the alternator generates more/less energy as the crank speed changes.

In other words...
Ohms law V = RI requires higher voltage to the battery in order for current to flow into it and charge. The regulator does this by regulating the voltage coming from the alternator and it's resulting current flowing into the battery, Hence the term "Regulator", .

The battery resistance is a constant so by increasing and regulating the input voltage we increase the current flowing into the battery.
The regulator limits this to 14.4V to limit the amount of current flowing into the battery in order to not damage it.

So as far as the battery is concerned, the regulator looks like another battery but at 14.4 volts.

Since voltage, like water flows downhill, a higher voltage 14.4V will flow current to the lower 12 volts of the battery and charge it.

I hope this makes sense.

Todd

While it makes sense, Todd, the SOHC4 regulator does not work the way an electronic regulator might.

The so called regulator on the SOHC4 is more aptly termed a battery voltage limiter, as it senses the battery voltage and then diminishes the alternator power output to keep it from over charging the battery. The control output levels are full on, about half power, and off.  The battery dominates the system voltage and slowly changes level depending on system load and alternator output.  The regulator can switch states rapidly between full output and half, for example.  The battery capacitance smooths these rapid state changes into an average value at the battery terminals.

I expect that there are battery charge systems where the regulator works as you describe.  It's just that the SOHC4 isn't one of them.

Cheers,

[Pinhead]

And thus converting to an electronic regulator is a HUGE upgrade from the "battery voltage limiter" which will make your battery last much longer and your total electrical system much more efficient.

Check the link in my sig.

[GammaFlat]

Here's a multi-part series that covers batteries and charging pretty well.  A lot of it is overlap of what has been contributed here but it is great reference and I found it helpful from a theoretical standpoint (even though it's from a Goldwing site.... well, it's a Honda isn't it?)

http://www.wingworldmag.com/archives/may2001/magazine/article/electricity.html

[HondaMan]

Is it true that the alternator is switched to provide more power when the lights are on?

I've often wondered as my 500 seems to go slowely flat when I run it during daylight with the headlight on. With every other bike on the road running like this I often tell myself that "these old bikes were never meant to be run with the lights on 24/7"

Should I keep charging overnight once per week or is there something else wrong with my charging system? (Battery is new - everything else is 32 years old!)

Steve:
If you have a stock headlight and stock ignition coils, the CB500 should keep up fine. Check for poor battery connections, especially at the main battery ground, and the auxilliary ground, often found near the regulator/fuse assembly (it goes to the frame). These often get corroded over time and cause poor performance. The regulator on these bikes is in FULL CHARGE mode when battery power releases the little relay inside of the regulator: this happens at low battery voltage. When the voltage goes HIGH (usually over 13.8 volts or so), the relay pulls IN, which reduces the field current and the alternator current drops to 50% or so. This activity is constant ON-OFF-ON while you ride, usually ON below 2500 RPM on a 500.

The stock headlight was only 45/55W, though. Most halogens are at least 50/60W, and many are higher than that. If yours is up in the higher range, switch it to a 50/60W bulb and the problem will likely just go away. This was the "fix" I applied to both my 500 and my brother's, because the laws of Missouri and Illinois required LIGHTS ON always. Oh, and I switched the tail lamp bulb to the 1034 type (original spec bulbs) because the 1157, while it fits and is more popular, draws nearly 50% more current, too. 

[TwoTired]

And thus converting to an electronic regulator is a HUGE upgrade from the "battery voltage limiter" which will make your battery last much longer and your total electrical system much more efficient.

I don't know why you would say such a thing?  As long as the electronic "regulator" controls the alternator field coil, it is still a battery voltage limiter.  The electronic one likely has more steps in the control than the stock mechanical one.  But, it still monitors the battery voltage and adjusts alternator output to keep from overcharging the battery.

A regulator such as the one Todd was describing, would be inserted in the path between alternator's rectified output and battery.  I think the permanent magnet type alternators employ this type of regulator.

Cheers,

[SteveD CB500F]

 I switched the tail lamp bulb to the 1034 type (original spec bulbs) because the 1157, while it fits and is more popular, draws nearly 50% more current, too.

I started this thread a long time ago and (under the tutelage of TT and Bryan) have a much better understanding now. I even fix up other people's bikes!

Now, about this rear bulb.  Surely the standard tail light is a 21/5W (?) Why do you say that they draw 50% more power than the original? Was the original only 12/3W?

[HondaMan]

 I switched the tail lamp bulb to the 1034 type (original spec bulbs) because the 1157, while it fits and is more popular, draws nearly 50% more current, too.

I started this thread a long time ago and (under the tutelage of TT and Bryan) have a much better understanding now. I even fix up other people's bikes!

Now, about this rear bulb.  Surely the standard tail light is a 21/5W (?) Why do you say that they draw 50% more power than the original? Was the original only 12/3W?

In the 1960s, the 1157 bulb was the 18w/5w combination, and the 1034 was 12/3w. During the 1980s, though, manufacturers of the 1157 seemed to abandon the "old standard", and the 1157 migrated upward to be (actual measurements, here) 26/12w (as measured at the time, 1981). I came across this problem because I was servicing the sequence-flash taillight kits for the old Ford Cougars and the like: they were originally set up for the old 1157 bulbs, and the "new" ones were burning them out. I have a collection of 1157 bulbs in my "tech history" bench, and they are dated by decade: the one I bought last year from Checker Auto (Sylvania brand) measures 28/12w at 12.0 volts. It came in a 2-pack: I put one in my Fairmont, and it has now melted the bulb socket. I think the Chinese builders are just making this problem even worse now.

[SteveD CB500F]

Well I'll be ***$$&&***

28/12W for a stop/tail...

There are two of those in the back of my Triumph - my wife still bought me a hi-vis jacket afetr following me down the motorway one drizzley morning. She said that, compared to most of the cars, I was almost invisible in the spray and poor light.

Did you do a straight VI measurement?

I might try that.

On a similar thread, if headlamp bulbs are built to a similar standard, who's to say that I'm not trying to light a 100W lighthouse with my puny 500/4 alternator... (?)

[TwoTired]

I've been looking at a few bulb specs and they seem to have a wattage rating based on 12.8 V, which is closer to a systems operating voltage than 12V. 

But, it's not hard to believe mfgs don't meet, exactly, their specifications.  Further, the spec may be written to require >at least< the wattage rating.  Which means they may manufacture on a bias to exceed rated spec. and to avoid rejected parts fallout that may go along with some variability on non-precision parts.

Cheers,