maylar
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More charging info
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Fast Eddie
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I recall that you chaps seldom saw eye to eye. But as a confirmed ’back of the class’ layman, it seems logical to me.
He covers a lot in the linked article, mind sharing which parts you’re unconvinced by and why?
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You’ve got me Googling.
Staying in the correct voltage range is very important with Lithium
I know this has been discounted by some previously, but the information I have from a Lithium battery manufacter and other sources indicate thermal runaway can occur at either end of the voltage range.
Here is a fairly simple explanation.
One of these reactions forms lithium metal on the anode (instead of storing lithium ions inside the anode). “That can actually cause hotspots. And [the metal] can react with the electrolyte,” Jeevarajan explains. Another reaction releases oxygen gas from the cathode. With heat and a flammable electrolyte, she says, this is “a really good combination to [start] a fire
I know this has been discounted by some previously, but the information I have from a Lithium battery manufacter and other sources indicate thermal runaway can occur at either end of the voltage range.
Here is a fairly simple explanation.
Thermal runaway
A lithium-ion battery can overheat if it has too much or too little charge. Battery designers use a computer chip to control the charge level. When your device’s battery is reading 5 percent, it’s not almost entirely out of juice. But if the battery were to discharge way more, or be charged up too much, dangerous chemical reactions could occur.One of these reactions forms lithium metal on the anode (instead of storing lithium ions inside the anode). “That can actually cause hotspots. And [the metal] can react with the electrolyte,” Jeevarajan explains. Another reaction releases oxygen gas from the cathode. With heat and a flammable electrolyte, she says, this is “a really good combination to [start] a fire
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I'm thinking that 13.8 - 14.6 voltage range is cruise or when the regulator is excited enough to generate that much DC voltage. My little lithium setup is in that voltage range above what I have to assume (no tach, ass out of u and me thinking) is 1200 RPM with the single phase alternator regardless of what the amp chart says. So from now on I'll blip or hold the throttle open a little on occasion if stuck in traffic. As far as I'm concerned, it works. The spec is not that hard to meet on a kick start bike as I see it.
Like most of the disasters reported on the internet the melted stators are more than likely 99.99% user neglect. If it was fact, my stator would be a puddle in my primary by now, and Tri-Spark would be out of business. No?
Like most of the disasters reported on the internet the melted stators are more than likely 99.99% user neglect. If it was fact, my stator would be a puddle in my primary by now, and Tri-Spark would be out of business. No?
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I’d like to take this opportunity to remind everyone that I’m an uneducated idiot.
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And current multiplied by next to no voltage is next to no power, which causes next to no heat.
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I resemble that remark.
Ok ,would you be able to put forward some supporting ac theory ,electomagnetic field analysis, equivalent circuits and formulae for the 'on bike' situation .I have to admit remembering back some 48 years ago to permanent magnet alternators (dynamos) and the effects of shorting output has on the magnetic flux and any change in inductance is a struggle and I will have to do revision.Also the effects that temperature has on the magnets and the resulting change in output.
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If you short the output of the alternator you now have maximum Current and so start to heat the coil windings.For a comprehensive view of the alternators read "High power interior Permanent Magnet Alternator for Automotive Applications " by Chong-Zhi Liaw March 2013 . It is on the net takes a good couple of hours to read , it is a total of 176 Pages and covers just about everything,Pg 45 is the short circuit section.
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Well, all this discussion/science is, uh...interesting, I guess but the reality is that in real life, all the various charging combinations from OEM to whatever the latest advertised component magic seems to work OK. And sometimes it seems to me that the 'science' is proven to be incorrect. For example, there are posts that the OEM-type charging system is not suitable for Lithium (Shorai) batteries. Yet, my Shorai 18AH has been working flawlessly since 2010 with Alton E-start added in 2012. The charging system for the Shorai consisted of the OEM for 2 years and the (unnecessary) installation of a Podtronic concurrent with the installation of the the Alton.
Somebody's science says it won't work; real life experience proves it does. Why is there even a discussion? If the science doesn't fit reality, the 'science' that was used is wrong for the application/purpose.
Somebody's science says it won't work; real life experience proves it does. Why is there even a discussion? If the science doesn't fit reality, the 'science' that was used is wrong for the application/purpose.
Fast Eddie
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Becasue we live in an age whereby the phrase “THE science says….” is supposed to trump all other opinions.
Trouble is, there is no such thing as THE science. There is science, which is the controlled testing of hypothesis based on clear fixed assumptions. And there are scientists, who conduct said experiments.
If THE science was a thing, it would be impossible for scientists to disagree! Whereas it seems to me that scientists are becoming like accountants…
You know the old saying about accountants? Ask 10 accountants a question and you’ll get 11 different answers !
But I’m not trying to poo-poo our attempts here. If someone were to scientifically test a few different alternator / regulator / battery set ups with a focus on voltage, stator temp and regulator temp it would surely be fantastic.
Big job tho…
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I did a small rough and ready static test yesterday, with a digital meter. It was hard to read such a low resistance, but I thought I could discern 0.1 ohm across the Alton single phase permanent magnet dynamo replacement.
Today I think I’ll run the bike with a 0-30 amp A.C. ammeter across the output leads of the alternator, with no load apart from the ammeter, which appears to have less even resistance than the alternator.
Anyone want to predict what I’ll find? I don’t actually know what amps or watts the Alton is rated at.
Fast Eddie
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Which Alton are you playing with TT, a dynamo replacement type, or a Commando e-start type?
I’m also very interested in knowing more about the dynamo replacement type and whether or not they’re compatible with a healthy Li battery relationship.
I believe both types are rated at a max of 150w. But what the volt or watt or amp output is at different rpm I’ve no idea.
I’m also very interested in knowing more about the dynamo replacement type and whether or not they’re compatible with a healthy Li battery relationship.
I believe both types are rated at a max of 150w. But what the volt or watt or amp output is at different rpm I’ve no idea.
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It’s a dynamo replacement, on another make of popular twin cylinder bike.
It’s an old Alton. Not even sure how old.
It’s an old Alton. Not even sure how old.
Yes, obviously this is the case, max current but with very little voltage. Even the research paper you mentions shows this for a far more powerful alternator.
Your theory is correct, but the heat generated when the coils are shorted is very little in the lucas stator, otherwise they would be one ride only devices when used with the Podtronics which has been about for years.
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But I’m not trying to poo-poo our attempts here. If someone were to scientifically test a few different alternator / regulator / battery set ups with a focus on voltage, stator temp and regulator temp it would surely be fantastic.
I suppose - from an "Ain't that interesting?" point of view but what is expected from the work? As someone else pointed out, there is no long list of burned up alternators caused by the various (or a particular) voltage regulators that have been used over the years.
I would suggest that the most important spec from various regulators is the VDC output, ASSUMING the regulator can handle the alternator wattage. Obviously if you have a 200W alternator, you don't want a regulator that can only accept 150W!
But the charging output of the regulator is a critical spec.
FWIW I tested the OEM Lucas vs my Podtronics some years ago and found that the Lucas provided from .1 to .2 VDC greater output than did the Pod at pretty much any engine RPM...
I suppose - from an "Ain't that interesting?" point of view but what is expected from the work? As someone else pointed out, there is no long list of burned up alternators caused by the various (or a particular) voltage regulators that have been used over the years.
I would suggest that the most important spec from various regulators is the VDC output, ASSUMING the regulator can handle the alternator wattage. Obviously if you have a 200W alternator, you don't want a regulator that can only accept 150W!
But the charging output of the regulator is a critical spec.FWIW I tested the OEM Lucas vs my Podtronics some years ago and found that the Lucas provided from .1 to .2 VDC greater output than did the Pod at pretty much any engine RPM...
