More charging info

@ggryder I think you are getting some of your terminology wrong.


Your rectifier is clearly doing plenty from your pic!

Rectification is where the AC output is converted to DC.


Without rectification, you output would be looking like this:




Half wave rectification would look like this:




Full wave rectification (which is what we have on our bikes whether it be standard or aftermarket), and is what you show in your pic is where that missing output (from below the line) is moved up top.
So a much smoother, less choppy output, than the half wave rectifier counterpart.

(sorry for hacking your pics by the way, but I hope it helps)



The regulation part is what you are showing in your second part - this is where the output is clipped when it gets to a certain point (between 14 and 16 volts in your case).
You can see it dropping down to 3 volts, because the circuit is cutting out then switching back on again.

You can tell this is the older (but perfectly good) SCR style, as the output is quite choppy.

The newer MOSFET ones cut out and back in much faster, so the output curves look a lot smoother.


I did the same research as you are doing when I had charging troubles, and it's all very fascinating - there is a lot of good info out there.

Thanks gforce. A slip of the keyboard on my part, "in this case the rectifier isn’t doing anything" should have been "in this case the regulator isn’t doing anything".
I spotted it after my opportunity to edit had passed. LAB has offered to make the edit for me, so that should remove at least one point of confusion.
It's good to hear that you came to a similar understanding about the way this works in detail. It's unfortunate that the SCRs, once they are triggered, shut down the alternator output for the rest of the cycle, but like you say these system's seem to work anyway. I do have charging system problems, but I don't think the normal operation of the SCR is the cause.

Cheers! ~ Gary

worntorn said:

If I understand Grant Tillers info correctly, the Trispark MOSFET reg and the Shindengen MOSFET reg are shorting type regs like the Podtronics. They regulate by shorting the two AC alt legs. This makes the stator quite warm.
The Shindengen SCR Type 775 and 847 are series type, they switch the AC output off. The stator runs cooler with this type.

Glen

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Spot on I ripped out the trispark mosfet as on a long ride at 70 miles a hr it cooked my stator ...now have in a SH775 ...fixed ...note i have a Motorbatt battery in ...

Anyone have a source for a genuine Shindengen SH775 regulator here in the states?The best price I could find was $245.00.
Thanks,Mike

John Kranz said:

Spot on I ripped out the trispark mosfet as on a long ride at 70 miles a hr it cooked my stator ...now have in a SH775 ...fixed ...note i have a Motorbatt battery in ...

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After I wrote that I tested the Podtronics shorting reg and rm23 stator on the MK3 for heat build up.

After a 30 mile ride the heat build up in the stator was exactly the same when the regulator was doing nothing (battery discharged, lights and heated vest on) as with full regulation ( battery charged to full overnight, ignition electrical load only)
The Podtronics warmed up a little with the second scenario but nothing to worry about. The stator temp was also nothing to worry about.
My conclusion was that the stator doesn't mind the Podtronics shorting reg at all. It's been in place for a few years now and has done a few long trips in summer heat without a problem.

 Glen

John Kranz said:

Spot on I ripped out the trispark mosfet as on a long ride at 70 miles a hr it cooked my stator ...now have in a SH775 ...fixed ...note i have a Motorbatt battery in ...

Click to expand...

If this was a problem then we'd all be having similar failures all the time. The shunt type regs are in wide spread use across many bike and car makes for decades.

worntorn said:

If I understand Grant Tillers info correctly, the Trispark MOSFET reg and the Shindengen MOSFET reg are shorting type regs like the Podtronics. They regulate by shorting the two AC alt legs. This makes the stator quite warm.
The Shindengen SCR Type 775 and 847 are series type, they switch the AC output off. The stator runs cooler with this type.

Glen

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Are there any downsides to this type of regulator?

robs ss said:

Are there any downsides to this type of regulator?

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1. Availability to purchase known genuine parts.

2. Price

3. Fitting; they’re big so finding space for neat mounting can be a challenge.

However, I’m not aware of any potential downsides in operation ?

robs ss said:

Are there any downsides to this type of regulator?

Click to expand...

I expect they are more complicated, which may or may not matter.

Way to many apples and oranges in the OP and the rest. The rotor and stator have little to do with the question. It's a matter of the output voltage of the regulator at whatever current is being drawn at whatever rpm. Air cooled bikes should not be idled for any length of time related to the discussion. Commandos should not be lugged. So, the real question is the output voltage of the charging system within the safe range for a LiFePo4 battery with the bike operated properly?

I can answer yes if running a Tri-Spark VR-0030 regulator with any Lucas stator and I'm sure there are other regulators that are OK - I would not use the original system but it, in good condition, has been use successfully with them. PM if you want to understand why.

All that said, I recommend a 10.5 amp 3-phase Lucas stator with the Tri-Spark VR-0030 because the output is better at lower rpms. I do not recommend the 16 am 3-phase or any of the high output single phase stators unless you have additional equipment on the bike requiring more current. And then, only if you have updated at least your ground and Brown/Blue wires. Different discussion - PM is you want to understand better.

marshg246 said:

"Way to many apples and oranges in the OP and the rest. The rotor and stator have little to do with the question. It's a matter of the output voltage of the regulator at whatever current is being drawn at whatever rpm. "

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That information was in the very first Apples and Oranges post-

"If you don’t want to swap system with a regulator , then best would be to stick with lead-acid / gel batteries. They can tolerate the voltage swings, from the stock alternator

Glen

worntorn said:

That information was in the very first Apples and Oranges post-

"If you don’t want to swap system with a regulator , then best would be to stick with lead-acid / gel batteries. They can tolerate the voltage swings, from the stock alternator

Glen

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Part of what you said in post #1: "I used numbers for my RM23 since I have those. A high output 3 phase RM24 is stronger at low rpm, but I have not been able to find voltage data for it. My guess from the original Lucas chart is that the RM24 hits 13.1 v at about 2800 rpm."

The words you quoted above do not appear in post #1 of this thread.

Apples, Oranges, Misunderstandings and Errors:

There are no appreciable voltage swings with the battery in the circuit. As long as the battery voltage says in the safe range for all batteries all it well. A batter is charging is there is ANY voltage higher than its current internal voltage applied to is. If the charging system is not at a high voltage than the battery it is simply doing nothing and for the moment hurting nothing. Obviously long-term the battery is discharging and can get to low if the charging system is not at a higher voltage.

High output 3-phase and low output 3-phase both make more usable power at low RPMs than any output single-phase.

Stators put out AC voltage and 13.1 VAC will not come close to even 11 volts DC so I have no idea where you got a number like 13.1 v at 2800 RPM unless it is quoted in a complete bridge, Zener, and battery and it is 13.1 vdc.

All of the stators on a VAC meter will produce around 30 vac at higher RPMs.

At low RPMs a single-phase stators produce a sine wave. Three-phase status produce three sine waves 120 degrees apart. Therefore, once through the bridge, there are two positive voltages per revolution for single phase and six for three phase. Obviously, the root mean square (effective) voltage is three times higher in three phase - hence the better performance at lower RPMs.

Watts and watts capability mean next to nothing if comparing stators on a given bike. Power (watts) = Current * Voltage. If the voltage is stable (it's from a battery so basically is) and the current requirement doesn't change (same bike so it doesn't with the same things turned on) then the watts required/used do not change. A single-phase 16-amp stator will add NOTHING to a bike that only needs a single-phase 10-amp stator! A 14.5-amp three-phase also will add NOTHING to a bike that only needs a 10.5-amp three-phase stator.

The only thing higher capacity stators do when not needed is cause the Zener or regulator to be hotter.

marshg246 said:

Part of what you said in post #1: "I used numbers for my RM23 since I have those. A high output 3 phase RM24 is stronger at low rpm, but I have not been able to find voltage data for it. My guess from the original Lucas chart is that the RM24 hits 13.1 v at about 2800 rpm."

The words you quoted above do not appear in post #1 of this thread

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Yes those words (re regulation) do appear, but you would need to read the entire post to see them.

My inquiry at Shorai was about my particular charging system on the MK3, as it was.
After a tutorial from a Fireman friend this summer, I'm no longer considering lifepo batteries for the bikes. I do have some for power tools and have shifted those and the chargers out to the pump house.

Nonetheless, your information will be helpful to others who are using or considering switching to Lifepo batteries.

Glen

worntorn said:

Yes those words (re regulation) do appear, but you would need to read the entire post to see them.

My inquiry at Shorai was about my particular charging system on the MK3, as it was.

Glen

Click to expand...

worntorn said:

Yes those words (re regulation) do appear, but you would need to read the entire post to see them.

My inquiry at Shorai was about my particular charging system on the MK3, as it was.

Glen

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Yes, the last sentence of the answer from Shorai does say that. Which is an opinion of someone with limited info. I didn't quote your post on purpose. You asked a question and provided some info you found: "Lucas chart is that the RM24 hits 13.1 v at about 2800 rpm." That is ridiculous unless you're talking about after rectification and regulation but you didn't say that. Unloaded Lucas stators are in the 30 vac range at 2800 rpm.

Then there's the 200+ posts that are all over the place talking about a bunch of stuff that has little to nothing to do with the original question. I quoted none of it because it is all over the place. Several did say that they've been using LiFePo4 batteries for a long time without problems. We have had many other threads saying the same things and almost always people popping up with this and that study that have little to nothing to do with the issue. Full on fruit salad!

Just to be clear. Every Lucas stator and rotor meant for a 12-volt battery ignition in good condition can provide all the AC current and high enough ac voltage required run a properly used stock Norton Commando. With a the right rectifier/regulator, the "perfect" LiFePo4 charging current is no problem. IMHO the Tri-Spark VR-0030 is close enough. If you want perfection find a modern regulator meant for LiFePo4 and a 3-phase alternator and install a 10.5 amp Lucas 3-phase stator. If you do that, do not switch to AGM or Lead/Acid after installing them. A Zener in the middle to high side of tolerance is OK as well, one on the low side is iffy for charging. The thing I don't like about Zeners with LiFePo4 is that when they fail they tend to fail open which allows the charge voltage and thereby current to go way too high and that's real bad with a LiFePo4 battery between your legs.


Here's a write-up you'll find in several places. This form was on the JRC Website:



Here's a video of a guy testing a replacement Zener after his failed open - he was getting 25-30 volts across the battery with the failed Zener:

The replacement Zener is on the high side of tolerance, or his meter is not right.

worntorn said:

The other thread melted down from high voltage without ever answering the basic question-
Are any of the Lucas or Lucas type alternators suitable for running Lithium batteries in our old Nortons?
I thought it best to go right to the horse , Shorai.
I used numbers for my RM23 since I have those. A high output 3 phase RM24 is stronger at low rpm, but I have not been able to find voltage data for it. My guess from the original Lucas chart is that the RM24 hits 13.1 v at about 2800 rpm.

My question to Shorai-

" I would like to use a Shorai battery in my 1975 Norton Commando MK3.
The idle charging output is below the 13.1 called for by Shorai. Idle (1000 rpm) voltage output of the alternator is around 8 volts. At approximately 3500 rpm it reaches 13.1 v, according to testing done with a 100watt load.
If I maintain the battery voltage above the minimum 12.86 v by avoiding prolonged idling, will the Shorai LFX18 work well in the Norton?


Shorai' answer

Hi Glenn,



I wouldn’t recommend it. You would be discharging the battery when idling, and at 13.1V you would barely be charging the battery.



Ideally you would want to see about 13.3V at idle, and max 14.2V at higher RPM. 13.3-138V is pretty normal for a modern bike with a regulator, but I know your bike is not modern



If you want to run ANY lithium battery, it would be good to see the ranges mentioned above.



If you don’t want to swap system with a regulator, then best would be to stick with lead-acid / gel batteries. They can tolerate the voltage swings, from the stock alternator.

Click to expand...

Yes, use RM23 with a Tri Spark Mosfet rectifier / regulator with all the AC fed directly to it and you have enough voltage to charge a lithium battery. I sure I have in the past posted photos of this setup with 14.3V at tickover. Most Lithium batteries will accept up to 14.5V these days.