Biting the bullet on charging system

The Boyer PowerBox are just like the popular Podtronics units in that they are short-type regulator/rectifiers.

They are no more precise than the original rectifier - they use the same package of four diodes that is on the bike from new.

The original zener is great, as it dumps current to your z-plate - a perfect heat sink.

Whereas the short-type regulator/rectifier closes (shorts out) the AC side, resulting in the alternator stator getting hot.

1. a new regulator/rectifier is double insulated so it can be used on positive and negative earth bikes, so it can’t dump load like the zener does.
   No current is transferred through the casing - only heat is transferred.
   So the zener inside can only dump through the connection wires.
   
   
2. the manufacturers don’t want these units getting too hot, they are all encapsulated in resin which means too much heat will give premature failure, hence their idea of shorting the AC side to keep some of the load (and therefore heat) away.

I remain convinced this is the reason we continue to see more and more failed, cracked and melted alternators on our bikes.

If you are going to look at a modern regulator/rectifier please do look at the series-type unit like the Shindengen SH775 or their newer replacement SH847.

These are series-type units, and differ in their functionality in that they open the AC side when charge to the battery is not required (taking the load off the stator)

They are used on Yamaha motorcycles and Polaris ATV/Jetski/Snowmobiles.

As mentioned already, forum member @Jeandr has researched this extensively and I have bored many about this topic on several threads - it’s something I’m vocal about as I do believe that on this occasion the biggest brand (Podtronics) is not necessarily the best route to take.

The 6V (and 12V Indian Enfield) alternators ran with coils short-circuited, when the lights were off. On some bikes that meant every day for years.

I've also just "bit the bullet" and am moving to replace my dodgy Zener voltage control. Since I feel my existing oem stator & rotor are doing fine, and the 2 MC capacitor is obviously working well enough to start/run the bike without a good battery, no need to replace it, I'm only replacing the Zener and rectifier with a Typanium reg/rec. Nothing fancy, single phase, but does handle up to 200 W (should I upgrade to a higher output single phase stator one day) and it's a nice small size for easier/discreet mounting. $47 USD from Classic British Spares.

I had considered going with the SH775 reg/rec after reading all the posts in the Jeandr thread. It certainly is the right way to go if needing higher output, best possible wave form, best charging for lithium cells, and protection for the alternator winding power feedback etc. But maybe this is all overkill for the lowly oem stator output...which had been serving the bikes needs well up to this point. The Zener +ve earth supplies seem to have dried up as it is shown out of stock at quite a few retailers. Might have gone with renewing it had they been available but since I'm running low consumption LED lighting and my SparkBright warning lamp is showing over 15.2 volts at 2-3K+ rpm with headlight on, the Zener may be struggling to cope.

This is NOT an isolated incident.
Replace them all.
Before they cause trouble.
Cheap as chips.

concours said:

This is NOT an isolated incident.
Replace them all.
Before they cause trouble.
Cheap as chips.
View attachment 12405 View attachment 12406

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Yup, mine are done.

Wow. Slick, Gtiller, ...and of course Jeandr --- Thanks! I had no idea that a modern regulator would dump to ground via SCRs. I could hardly believe it. What a perfectly ROTTEN way to "regulate"! Jeandrs information (and posts related to voltage vs rpm by Jaydee) is sufficient that besides the other diagnostics,

1) I will certainly buy the Shindengren SH775 (or equivalent) "series type" regulator and never look back. It's the only way to get the positive value of any upgrade in output without stressing the alternator.
2) I will contribute to the forum after finishing this post.

Ted

maylar said:

MKIII alternator is 180 watts, the extra zener is to handle the increased output current.

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Also requires the uprated Podtronics reg/rec if you go that route. The one for the lower-output systems will fry on a Mk III alternator. Don't ask me how I know.

Ted Lang said:

Wow. Slick, Gtiller, ...and of course Jeandr --- Thanks! I had no idea that a modern regulator would dump to ground via SCRs. I could hardly believe it. What a perfectly ROTTEN way to "regulate"! Jeandrs information (and posts related to voltage vs rpm by Jaydee) is sufficient that besides the other diagnostics,

1) I will certainly buy the Shindengren SH775 (or equivalent) "series type" regulator and never look back. It's the only way to get the positive value of any upgrade in output without stressing the alternator.
2) I will contribute to the forum after finishing this post.

Ted

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I’m an electrical Luddite, but I read the the words of those guys above and spoke with Gtiller and went with the Shindegen on my recent build. Certainly no regrets thus far.

I had the Shindengen SH775 on my shelf waiting to replace the Podtronics unit when on a whim I sold the bike. I've put a number of these Polaris sourced units on different brands of bikes for friends of mine. Norton, Triumph, Honda, Yamaha, and Suzuki. All have been trouble free and are a better design than the Podtronics.

I just bought an SH775 off eBay - gonna see if it'll charge my Shorai any better than the Sparx SCR controller I've been using.

maylar said:

I just bought an SH775 off eBay - gonna see if it'll charge my Shorai any better than the Sparx SCR controller I've been using.

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Did you ensure the unit is genuine? Lots of rip off types out there.

eskasteve said:

I had the Shindengen SH775 on my shelf waiting to replace the Podtronics unit when on a whim I sold the bike. I've put a number of these Polaris sourced units on different brands of bikes for friends of mine. Norton, Triumph, Honda, Yamaha, and Suzuki. All have been trouble free and are a better design than the Podtronics.

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Eskasteve: If it's still on your shelf, do you have the connectors and do you want a buyer? The only new units I'm seeing are SH847 -- as was said, basically a slightly upgraded SH775, but also quite a bit larger. I'd rather have the SH775 if its a real one (PM me about price)

Ted

Ted Lang said:

Eskasteve: If it's still on your shelf, do you have the connectors and do you want a buyer? The only new units I'm seeing are SH847 -- as was said, basically a slightly upgraded SH775, but also quite a bit larger. I'd rather have the SH775 if its a real one (PM me about price)

Ted

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https://www.partzilla.com/product/polaris/4012941#


Pretty sure this is the 775. I believe I still have the part number home if you need me to check. Price on this is actually $167.00

Just to summarize posts and differentiate between old zener system and the shunt regulators (i.e. podtronics and Boyer), the shunt regulators are essentially the same as the original Zener in that they both run excess current to ground. Sure, that's fine for voltage regulation on the DC side. But Jeandr's point is that it's not the same at all from the poor alternator's standpoint. Consider in our humble old system that the zener diode is always holding its reference voltage before it conducts, so if that's say, 14 volts or so, the net voltage drop to move current is the alternator emf, minus the zener voltage, minus the forward bias voltage of the bridge rectifier (about 1.4 volts if silicon), and minus the I*R losses of all the resistances. Thus, the zener current and the stator current, is not all that much. However, when the shunt type regulator SCRs fire, the SCR resistance is VERY low, as is the alternator coil resistance, and this is only thing holding back stator current except inherent magnetic limitations of the stator itself (the alternator magnetism saturates and it is physically limited that way). But the net alternator current is at its absolute maximum and is very high. I would think the opposing magnetic field set up in the stator, working against the rotor magnetism, would also tend to demagnetize the rotor faster than necessary. Like when in school we used to magnetize or demagnetize an iron rod by rubbing it with a stronger magnet. By contrast, the series type (i.e. SH775), monitor DC voltage and just block alternator current from flowing at all, except as needed to hold DC side voltage at target.

So, the conclusion is that the original zener system is OK for the alternator, and OK (not great) for DC voltage regulation. Shunt regulators are very hard on the rotor and stator, (ironically especially when lights are off) but provide very good DC regulation. The so called "series" regulators (e.g. SH775) are always easy on the rotor and stator AND provide very good regulation. No Brainer to me, except for cost to change.

Ted

Nice summary Ted.
Even the cost to change is easier to swallow once you’ve worked out you’re gonna save money on new stators, and possibly rotors, in the longer run.

Ted Lang said:

Just to summarize posts... The so called "series" regulators (e.g. SH775) are always easy on the rotor and stator AND provide very good regulation. No Brainer to me, except for cost to change.

Ted

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Ted - thanks for your explanation... but I don't have a great electrical mind.
Does the Pazon RR12-3 fit into the "series" regulators you recommend?
Cheers
Rob

Rob-- I don't know about that specific model, but it should be easy to find out. (I'll see what I can find in the morning, or perhaps others know off hand.) The type of regulation is no secret, just not an advertising point. Boyer told me directly via their tech support when I asked. Outside my preference, there are certainly folks that use the shunt type very successfully; actually the majority. But I would say they regulate the DC side very well... based on the grace of robust alternator design. Don't forget that even Shindengren's other models are the shunt type. I just personally find the idea of shorting out the alternator to control its voltage sort of barbaric.

I understand the explanation regarding why the SH 775 is a superior regulator design to the Lucas OEM and especially the Podtronics. BUT...is this difference of any practical advantage in operation? I had a Lucas 3 phase system on the bike for years and it worked perfectly. I installed a Podtronics when I installed the Alton E-start (single phase alternator) and it has also worked fine with no failed alternators due to overheating.

So, although SH775 may be a better design, does the 'better design' provide any functional/operational improvement over the Lucas or Podtronics in our application?

MexicoMike said:

So, although SH775 may be a better design, does the 'better design' provide any functional/operational improvement over the Lucas or Podtronics in our application?

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No.

Tornado said:

Did you ensure the unit is genuine? Lots of rip off types out there.

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The seller says it is...

https://www.ebay.com/itm/380704480069