Topic: Possible issues for poor charging..

[maxheadflow]

When you see parts of these bullet connector looking dark, you may have issues.

[maxheadflow]

The bullet side was taking heat.

[maxheadflow]

They all got cut off and replaced.  To help with them not becoming Ohmic and heating up I soldered the bullet.  Female sides looked good..

[Deltarider]

Mwah... I don't see much of a problem. They happen to be in a hot spot. What was the issue?

[maxheadflow]

Yes, the engine is a hot spot but the places I identified are getting way hotter.  Motor temp should not ever get above 250F. These connections are getting up to about twice that. You can see where the insulation is melting and the brass has changed color.  Honda does use higher temp insulation on the other side but the heat is coming from the crimp area.

[PeWe]

Good investigation that should due on the company I work for when getting a returned cable/ harness investigating the root cause

1 classic crimping mistake is too short removal of insulation which become part of the crimp where only the strands should be part of the crimped connector. That area not air tight, it will corode and cause resistance.

[Jerry Rxman Griffin aka MuthaF'er]

Those are not that bad IMO but yes, that is always an area of resistance and heat. Have you seen any others!?!

[maxheadflow]

Those are not that bad IMO but yes, that is always an area of resistance and heat. Have you seen any others!?!

Not yet but I'm sure there are others. A common issue I found with these bikes years ago was the rectifier and main motor connectors would have a loose connection. Get a loose connection one of the phases and the rectifier would die. 

[TwoTired]

Those are not that bad IMO but yes, that is always an area of resistance and heat. Have you seen any others!?!

Not yet but I'm sure there are others. A common issue I found with these bikes years ago was the rectifier and main motor connectors would have a loose connection. Get a loose connection one of the phases and the rectifier would die.

A loose connection means poor contact area and higher resistance.  Pass current through a resistance and you get heat.

Soldered connections are worse than crimped in vibration environments, if not supported outside the join.  They can't flex at the join without eventual metal fatigue breakage.  Crimp connections last much longer if you treat the crimp with electrical or silicone grease to block the elements for exposure to air and humidity.  The alternative is to use noble metals, which are expensive.

Cheers,

[maxheadflow]

Those are not that bad IMO but yes, that is always an area of resistance and heat. Have you seen any others!?!

Not yet but I'm sure there are others. A common issue I found with these bikes years ago was the rectifier and main motor connectors would have a loose connection. Get a loose connection one of the phases and the rectifier would die.

A loose connection means poor contact area and higher resistance.  Pass current through a resistance and you get heat.

Soldered connections are worse than crimped in vibration environments, if not supported outside the join.  They can't flex at the join without eventual metal fatigue breakage.  Crimp connections last much longer if you treat the crimp with electrical or silicone grease to block the elements for exposure to air and humidity.  The alternative is to use noble metals, which are expensive.

Cheers,

So how much power do you think was lost to heat that connector up?   3-5 watts each?  Possibly.  Alternator puts out what? 120 watts? (don't know).   

You absolutely correct about solder being an issue in high vibration environments.  If you ever owned a 50/60s brit bike you would know. Pretty much all of their bullets were soldered. No strain relief.   The trick is on these bullet connectors is to solder after the first crimp and do the strain relief/insulation crimp after solder has cooled. Don't let the solder flow up the wire.   In most cases you don't need to solder all of the wires on a bike, mainly the ones that carry high current and the environment allows for moisture to get to the connector.   

[TwoTired]

So how much power do you think was lost to heat that connector up?   3-5 watts each?  Possibly.  Alternator puts out what? 120 watts? (don't know).   

A 550 alternator is rated for 150W at 5000RPM minimum.
The 750 Alternator is rated at 210W  at 5000RPM.  Both put out about 1/3 of rated at idle RPM.  (Specs are from memory, books not in hand.)

The power loss is calculable if you know the voltage drop at a certain current flowing through it, or by knowing the actual resistance and current or voltage drop. P=I²R.

The heat build up depends on the heat removal scheme.  Air cooling the connector with airflow or conducted heat out the wire path.  This is why you have insulation discoloration, the wire conducted the heat to it.   You can only cool if there is a place for the heat to go, otherwise it builds upon itself.  Inside the alternator housing, there is no air flow and no source of cooler air to replace what was heated.  Heat builds, until it gets to just above case temps, whether the case is cooled or not.

The old Easy bake kids ovens would bake at 350 degrees F in an enclosed space, with a 40 watt bulb.  40 watt bulbs in open/circulating air don't get that hot.

You can get some pretty extreme temps with very low wattage inside an evacuated or enclosed space. 

Cheers,

[Deltarider]

Yeah... I just don't agree with this simple applying Ohm's law to just anything anytime and deducting predictions of Watts used or Amps drawn. Let's take the coils. Mines are rated 3 Ω. If you calculate with Ohm's law and then postulate, corrected for dwell, the Watts they will consume or Amps they will draw - whatever - it's just all too simple. The given resistance of the primary of the coils is static. When in use, it's a different story. It has to do with the nature of the coil, in other words what it does dynamically. Now I can go on here for hours about current and induced countercurrent and the curve in saturisation, but hey, I am not a native speaker. Any of you - and I invite you to do this - can put an ammeter in between the killswitch and the coils and measure what current the coils actually draw dynamically. You will be surprised and all these claims about 3 Ω coils taxing the charging system too much, it's just BS. Yes, they draw more than stock coils, but not that much more. How I know? Well, not only have I myself been doing the test not that long ago, also I've been running 3 Ω coils for over 20 years in combination with a 60 Watts halogen, later even added my homebuilt EI that draws another 0.6 A and still I have not met any charging problem whatsoever. Now we can all dish up theoretical exposé after theoretical exposé and show maybe even more impressive pictures representing Ohm's law, but I think most here will be much more helped with results coming from everyday practice. Thank you very much.

[maxheadflow]

So how much power do you think was lost to heat that connector up?   3-5 watts each?  Possibly.  Alternator puts out what? 120 watts? (don't know).   

A 550 alternator is rated for 150W at 5000RPM minimum.
The 750 Alternator is rated at 210W  at 5000RPM.  Both put out about 1/3 of rated at idle RPM.  (Specs are from memory, books not in hand.)

The power loss is calculable if you know the voltage drop at a certain current flowing through it, or by knowing the actual resistance and current or voltage drop. P=I²R.

The heat build up depends on the heat removal scheme.  Air cooling the connector with airflow or conducted heat out the wire path.  This is why you have insulation discoloration, the wire conducted the heat to it.   You can only cool if there is a place for the heat to go, otherwise it builds upon itself.  Inside the alternator housing, there is no air flow and no source of cooler air to replace what was heated.  Heat builds, until it gets to just above case temps, whether the case is cooled or not.

The old Easy bake kids ovens would bake at 350 degrees F in an enclosed space, with a 40 watt bulb.  40 watt bulbs in open/circulating air don't get that hot.

You can get some pretty extreme temps with very low wattage inside an evacuated or enclosed space. 

Cheers,

Know the formulas well.   Retired EE.  Smoked a few resistors in my time.  Have turned a screw into a light. How hot it gets depends on how well the resistance can dump heat.

[maxheadflow]

Yeah... I just don't agree with this simple applying Ohm's law to just anything anytime and deducting it to predictions of Watts used or Amps drawn. Let's take the coils. Mines are rated 3 Ω. If you calculate with Ohm's law and then postulate, corrected for dwell, the Watts they will consume or Amps they will draw, whatever, it's just all too simple. The given resistance of the primary of the coils is static. When in use, it's a different picture. It has to do with the nature of the coil, in other words what it does dynamically. Now I can go on here for hours about current and countercurrent and the curve in saturisation, but hey, I am not a native speaker. Any of you - and I invite you to do this - can put an ammeter in between the killswitch and the coils and measure what current the coils actually draw dynamically. You will be surprised and all these stories about 3 Ω coils taxing the charging system too much, it's just BS. And I can know: not only have I been doing the test not that long ago, also I've been running 3 Ω coils - without even a ballast resistor! - for over 20 years in combination with a 60 Watts halogen, later added my homebuilt EI that draws another 0.6 A and still I have not met any charging problem whatsoever. Now we can all dish up theory after theory and show even more complex pictures of Ohm's law to impress, but I think most here will be helped with results from everyday practice. Thank you very much.

Calculating current draw based on resistance of a coils that are switching is plain wrong.. The whole reason for the resistance definition is to tell you what peak drive capability of the controlling device needs to be.  Remember the coil is nothing but a big inductor coupled to another inductor (transformer).  The resistance is nothing more than the resistance of the primary winding.  Feed the coil switched voltages or even AC and you have to analyze the energy flowing into and out of the coil.  In that case it's more AC / transient circuit analysis and not simply V = IR.   R becomes impedance Z which is complex.   Z = R +jX.  As a result V and I also become complex tho they don't give them another name.

[bryanj]

What it all boils down to with electrickery is that you cant see,smell or hear it but dont it ever bite!!
PLUS you have to feed mor into the battery than you take out or everything stops working.

[PeWe]

Do not forget that the electrical stuff must be properly sealed to keep the smoke inside. If letting it out it will stop working.

Spare smoke possible to order from our friends in UK, Lucas.
I think they have a huge NOS spare warehouse somewhere.

[rotortiller]

Where is Joe Henry when you need him LOL

[Deltarider]

Yeah... I just don't agree with this simple applying Ohm's law to just anything anytime and deducting predictions of Watts used or Amps drawn. Let's take the coils. Mines are rated 3 Ω. If you calculate with Ohm's law and then postulate, corrected for dwell, the Watts they will consume or Amps they will draw - whatever - it's just all too simple. The given resistance of the primary of the coils is static. When in use, it's a different story. It has to do with the nature of the coil, in other words what it does dynamically. Now I can go on here for hours about current and induced countercurrent and the curve in saturisation, but hey, I am not a native speaker. Any of you - and I invite you to do this - can put an ammeter in between the killswitch and the coils and measure what current the coils actually draw dynamically. You will be surprised and all these claims about 3 Ω coils taxing the charging system too much, it's just BS. Yes, they draw more than stock coils, but not that much more. How I know? Well, not only have I myself been doing the test not that long ago, also I've been running 3 Ω coils for over 20 years in combination with a 60 Watts halogen, later even added my homebuilt EI that draws another 0.6 A and still I have not met any charging problem whatsoever. Now we can all dish up theoretical exposé after theoretical exposé and show maybe even more impressive pictures representing Ohm's law, but I think most here will be much more helped with results coming from everyday practice. Thank you very much.

Calculating current draw based on resistance of a coils that are switching is plain wrong.. The whole reason for the resistance definition is to tell you what peak drive capability of the controlling device needs to be.  Remember the coil is nothing but a big inductor coupled to another inductor (transformer).  The resistance is nothing more than the resistance of the primary winding.  Feed the coil switched voltages or even AC and you have to analyze the energy flowing into and out of the coil.  In that case it's more AC / transient circuit analysis and not simply V = IR.   R becomes impedance Z which is complex.   Z = R +jX.  As a result V and I also become complex tho they don't give them another name.

Very right so. That's why not that long ago I performed a test measuring the amps drawn by the coils dynamically. In total I measured around 3A at idle and just a tad over 2A when revved (which makes sense). With 3 Ω coils, mind you! Read: http://forums.sohc4.net/index.php/topic,175144.msg2038035.html#msg2038035 It's such a simple test that I invite anyone to check my findings or - even better - post the results with standard 4,7 Ω coils. Then we'll have the full picture. Pardon my ignorance but who's Joe Henry?

[rotortiller]

https://en.wikipedia.org/wiki/Henry_(unit)

who's Joe Henry?

[Deltarider]

Wow! That's new to me. Thanx! One never finishes learning, do you.

[TwoTired]

If you use an averaging and/or sampling meter to measure the current spikes into an ignition coil, you will likely have an erroneous measurement of true current demand.  You can not normally determine if the sampling period occurs during the inrush spike, part of it or in a period that misses the initial inrush event entirely. 

Most on this forum don't have a clue as to how to measure current in an inductive circuit.  It's a motorcycle forum.  Not one revolving about advanced electronic issues.

The simple equations from ohm's law are more appropriate to this audience, and many are unaware of even those electrical basics.

Who is going to calculate formulas using impedance, inductance, capacitance, frequency, inductive reactance, capacitive reactance, etc?  Those formulas are jibberish, or numbing to most motorcycle enthusiasts. Certainly, the recharge event and its characteristics depends on the previous discharge event particulars and its actual depth of discharge, as well as the magnetic core saturation and permeability.  Many of these factors can change with RPM/frequency, and with coil sample to coil sample.

Presenting other than a simple formula for rudimentary calculations or predictions, is far more apt to be of use (if not accurate to the nth degree) to most on this forum, imo.

Cheers,

[maxheadflow]

You can find DVMs that that will measure RMS currents, but they really won't be that far off from an average current which a cheap amp meter will see.  Average DC current is what the battery wants to see anyway.. The 3 amps at idle / 2 amps at Rs on 2 3 ohm coils makes total sense. At idle the coil becomes more fully saturated due to the points being closed for a longer period than at higher RPMs so it draws more current. Once the coil is saturated, there is no more energy to store, current goes up  and the coil heats. 

You still measure current the same way whether AC or DC.  It's when you want to know the power that it becomes more complex when measuring AC or transient signals.

[TwoTired]

At idle the coil becomes more fully saturated due to the points being closed for a longer period than at higher RPMs so it draws more current. Once the coil is saturated, there is no more energy to store, current goes up  and the coil heats. 

The coil heats because the primary resistance is then pure resistive after the charging impulse, and eats power per ohm's basic law for that portion of time the points are closed.

I've found that DVM's mostly are inaccurate measuring pulse events, particularly fast ones.  Such things are better measured with a scope.  You usually need a fast one to do it, as the rise time has an effective frequency component.  And digital scopes can still give you aliasing, due to sampling rate masking.  Lab quality ($) usually works better than the ones for automotive use in my experience, as the inputs of them convert and display fast rise times better.

Cheers,

[maxheadflow]

At idle the coil becomes more fully saturated due to the points being closed for a longer period than at higher RPMs so it draws more current. Once the coil is saturated, there is no more energy to store, current goes up  and the coil heats. 

The coil heats because the primary resistance is then pure resistive after the charging impulse, and eats power per ohm's basic law for that portion of time the points are closed.

I've found that DVM's mostly are inaccurate measuring pulse events, particularly fast ones.  Such things are better measured with a scope.  You usually need a fast one to do it, as the rise time has an effective frequency component.  And digital scopes can still give you aliasing, due to sampling rate masking.  Lab quality ($) usually works better than the ones for automotive use in my experience, as the inputs of them convert and display fast rise times better.

Cheers,

Well I won't argue with you about resistance as being purely resistive..  I think you mean impedance.. We are saying the same thing.

Second part,  rise time and frequency on scopes are related.  Rise time is roughly 0.35 divided by peak bandwidth.  Most newer digital scopes can sample at 100 mhz without what you call masking.  High speed ram took care of that.  Still you can alias when samping really slow.  Say you want a 10 second sweep, you won't get a 100 mhz sample rate.

[HondaMan]

The CB750's alternator bullets on the K0 and most of the K1 engines were the 3mm size. Honda increased these to 3.5mm in the late New Factory K1 engine and all later ones. In the K7/8 I have even seen some brass ones, but most were zinc-plated steel, and the zinc comes loose after 10 years, making high ohms and heat. The tip-off, if you are looking at yours, is the female jackets on the socket side: if they are hard like plastic, time to replace both ends. Use the modern brass ones and you will also pick up a little extra power (as less losses), too.

Don't overlook the other end of that cable, either: the sockets and blades in the 8-circuit white plug are often grungy, even corroded, and I have seen the alternator circuits melted in this connector shell from it.