Shindengen R/R update; S4 fitting annoyances and lithium battery info

[Mr Gazza]

Frickin' good article Spuggy!
I did a bunch of searching and I believe this is the video that you referred to? https://youtu.be/TYxtCC330Xg
I couldn't get your link to work.

I would agree about the alternator taking a lot of power. Many years ago I was fiddling with a Honda or Yamaha and I disconnected the alternator cables whilst it was running. To my amazement the tickover raced up by about 2000rpm and then the alternator dragged it back down to normal when I touched the cables back together. Whatever bike it was would have probably been sub 20bhp but I think the alternator would have been sapping a few of those.
This makes a mockery of those who say that it doesn't cost any more to have the lights on, as clearly more current demand puts more load on the engine and therefore burns more fuel... I'm into fitting one of those R/Rs that only draws what it needs.

[spuggy]

Originally Posted by Mr Gazza

Frickin' good article Spuggy!

Thanks Mr Gazza!

Yeh, I spent about 20 hours googling/reading this time around so I didn't embarrass myself on the internet



thought I'd take the time to share; I still owe you guys lots, overall

Originally Posted by Mr Gazza

I did a bunch of searching and I believe this is the video that you referred to? https://youtu.be/TYxtCC330Xg
I couldn't get your link to work.

Yup, that's the one - since edited the embedded link to the same URL, as the board software doesn't like embedded links. Or it's disabled or summat..

Originally Posted by Mr Gazza

This makes a mockery of those who say that it doesn't cost any more to have the lights on, as clearly more current demand puts more load on the engine and therefore burns more fuel... I'm into fitting one of those R/Rs that only draws what it needs.

Heh. With a shunt, the only difference it makes having the lights on or off, is whether the power you generate is converted into light/heat in the bulbs, or heat in the shunt... Makes no odds to the motor, because the alternator is chucking out everything it can anyway

Those of y'all who tried to save battery money on your push bikes by using the dynamo-on-the-tire approach will have a pretty good idea how much drag it takes to generate even a pitiful couple of watts...

One of the forum pages, they measured power draw in the alternator leads, to check whether a specific R/R was a shunt or series type; basically, as soon as you switch off the load on a series R/R, the amps in the wires drops off to almost nothing. That's gotta make a difference.


All seemed kind of academic until I realized I had to replace the regulator anyway. And wasn't exactly brimming with confidence with the battery.

[Mr Gazza]

So will the series R/R meter power demand from the alternator and release more to the engine? Like when I disconnected the cables on my teeny bike? Or does the alternator still sap the engine whatever?

[spuggy]

Originally Posted by Mr Gazza

So will the series R/R meter power demand from the alternator and release more to the engine? Like when I disconnected the cables on my teeny bike? Or does the alternator still sap the engine whatever?

A shunt takes full power from the alternator all the time. It maintains voltage/current to what you want by bypassing (shunting) the excess away.

An SCR shunt gets damned hot doing this. A MOSFET shunt doesn't get so hot - but is still doing exactly the same 1960's thing, just with updated semiconductors that make it more efficient/turn less power into heat.

Any drag on the motor due to the alternator will be identical with both types of shunt; the alternator is running 100% output, 100% of the time.

I thought this was a pretty clear, readable explanation, of the difference between shunt/series R/Rs from triumphrat https://www.triumphrat.net/threads/c...upgrade.104504 - they're talking about the SH775 here:

It does NOT appear to be suited for the high rpm 4-cylinder Triumph 600-4's (TT600, Speed4, Daytona 600/650) - at high rpm it loses regulation on those bikes.
(However see further down this thread for details on the SH847 Series R/R which has been proven successful on those models)

It is made by Shindengen and has the exact same Form Factor as the FH012/020 series MOSFET Rectifier/Regulator that has enjoyed great acclaim & success.
A couple of things to note - it has lower current spec than the FH012/020, however still plenty adequate for the Twins (the FHO12/020 is actually way overkiil re current rating requirement anyway for the Twins); it is not MOSFET but SCR.

Wait I hear you cry - "you have been espousing the benefits of MOSFET regarding the reliability of these units, why are you now suggesting a replacement SCR type?"

Here is the SIGNIFICANT difference - this new R/R is SERIES - not SHUNT!!

Why is that of benefit?
The difference between Series & Shunt is that:

Shunt - the Stator always has to apply maximum generated current - when the R/R is in regulation it shorts across the winding to 'shunt' current away from the load directly back to the stator. In an SCR (OEM) Shunt Regulator the SCRs get extremely hot and they ultimately burn out if that heat is not adequately cooled - that is why OEM needs to up front directly in the cooling path.
Because of the way it operates, if you reduce the system load (e.g. turn off the lights) the R/R will actually have to shunt MORE current and will run hotter - but the stator load is the same regardless of whether the current is going to the load, or back through the SCR's.

Series - this is fundamentally different in that in a Series design, instead of diverting (shunting) excess current back to the stator to control the output voltage, the regulation works by interrupting the current path to the load. This means that the Regulator ONLY supplies current demanded by the load itself, and no excess current parallel path through a shunt. So the net result is that this type of Regulator is MUCH kinder on the stator because the stator is always supplying much less current! So the stator does not get so hot and its reliability increases significantly.
The fact that it has SCR's is not quite so problematic as in the Shunt application, because they are flowing less current and for a shorter duration. So they will not get as hot as when used in shunt mode.

This particular unit is a Shindengen SH775 regulator and is used on Polaris models.
It is VERY inexpensive - brand new -
e.g. $73 shipped!!!! ($60 & change plus shipping)
http://polarisparts123.com/partnumber-search/ (enter 4012941)

Polaris REGULATOR-3PH,35A,SERIES,105C for 2011 Polaris R11HR76AG/AR RANGER 6X6 800 EFI 4012941