How many Ah for my 1974 Commando?

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KNorton said:
Thank you gtiller.

FWIW, the voltage regulator should dump excess voltage not being used as heat. So even though you are using a state of the art charging system, if the bike doesn't use the "extra" power, it gets dissipated in the air stream as waste heat.

Forgive me if I'm incorrect. I'm still learning all I can about this bike and I'm certainly open to any and all useful ideas!
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That's exactly what happens with a Zener diode. Whether it happens with the various voltage regulators is not clear since I don't have the schematics. It is certainly an easy way to make a voltage regulator.

Another way is to vary the input AC voltage. This can be switching it off and on or limiting it. While some heat is generated in any electronics, much less is created that way.

Another value in switching the input is that you could easily eliminate or greatly reduce the leakage current that exists with the bike turned off.
 
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Madnorton said:
For those that have not tried yet, the Tri Spark Mosfet R/R will produce 14.39V at tickover and holds it there nicely as the revs rise, this is using a BSM and single phase stator. I am thinking about a Lithium battery but not happy with the way the cell balancing works. I am not sure, but would like each cell control system fused so in the event of failure it fails open and battery dies, and not overcharges and ignites. Nearly convinced on this Lithium technology, but not quite.
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As I have posted, I am and have been totally convinced of the Lithium technology (as used in the Shorai battery) BUT I can't see how a Trispark Mosfet R/R can RAISE the voltage to 14+ at idle...does it use a voltage converter and trade off amps for volts? Or have all voltage regulating systems up to now been so inefficient? Or is the alternator you are using so much more efficient than the typical ones used in our Nortons? OR...are you idling at 2500 RPM? :)

I thought my system was doing pretty well producing 13v at 1000 RPM!
 
MexicoMike said:
As I have posted, I am and have been totally convinced of the Lithium technology (as used in the Shorai battery) BUT I can't see how a Trispark Mosfet R/R can RAISE the voltage to 14+ at idle...does it use a voltage converter and trade off amps for volts? Or have all voltage regulating systems up to now been so inefficient? Or is the alternator you are using so much more efficient than the typical ones used in our Nortons? OR...are you idling at 2500 RPM? :)

I thought my system was doing pretty well producing 13v at 1000 RPM!
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I have no idea about your questions but here are somethings to consider.

The alternator puts out AC that is much more than 15 volts and it increases with speed. That AC is rectified into DC and then regulated to the charging voltage if the regulator is able.

Many factors are involved. For one, the battery both does the final smoothing of the voltage and also limits the voltage if not fully charged. Assuming a bridge rectifier (original or in a voltage regulator), losses occur across each diode.

All discussions of voltage, at whatever speed, would be more accurate with a good capacitor and no battery in the circuit. A battery needing charge will (within reason) take all the current it can get and will hold the voltage to a little above the batteries current voltage until it is fully charged.
 
@MexicoMike what do you mean raise the voltage?

The no load AC output of our alternators is about 60 volts.
With rectification this doesn’t equate to the 14.3 volts DC you see on your multimeter at this RPM.
There are a lot of variables in this equation, but assume at 3,000rpm our standard single phase alternator stator with a decent rotor that is going through a bridge rectifier is putting out around 38 volts DC.

As I say, it is more complex than that because output is lessened as the load increases, but the rule of thumb to give you a ballpark idea for no load conversion as I remember it from my college days is: average out in DC is 0.637 of the AC input.

I am sure @dynodave will be along to confuse me with complex calculations and terminology that I don't understand but this hopefully at least gives you an idea that voltage is not being raised!!!
 
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OK, so the standard regulators we see (Podtronics, Lucas OEM, whatever) all limit the voltage to 'normal' lead/acid charging voltage.

Then, if I'm understanding, that Mosfet RR being described allows a higher voltage output, better for optimum charging of a Shorai?

SO...the Mosfet RR allows the voltage at idle to be 14+ whereas using a Podtronics, OEM Lucas, etc will produce maybe 13 with the same alternator, No change other than the RR?
 
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The actual output voltage is a function of the regulator design, it's component tolerances, and the input voltage from the alternator. Can't get any more out than you put in. Design nominal would typically be 14.2 - 14.4 volts. That works for any type battery technology. As Dave has noted, even the stock zener was in that range nominally.

There are design tolerances, however, in any system. You can't categorically state that any one design of R/R will have higher output than another. Maybe an expensive one uses Schottky diodes, which have less than half the forward voltage drop of silicon. MOSFET vs SCR vs series vs shunt - you can't say one will be higher output than another.
 
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MexicoMike said:
As I have posted, I am and have been totally convinced of the Lithium technology (as used in the Shorai battery) BUT I can't see how a Trispark Mosfet R/R can RAISE the voltage to 14+ at idle...does it use a voltage converter and trade off amps for volts? Or have all voltage regulating systems up to now been so inefficient? Or is the alternator you are using so much more efficient than the typical ones used in our Nortons? OR...are you idling at 2500 RPM? :)

I thought my system was doing pretty well producing 13v at 1000 RPM!
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The stator output is fed directly to the rectifier. In use the rectifier does not get warm as it is rated at 20 amps. I have a video clip of it doing, so which I can email if need be.
 
gtiller said:
@MexicoMike
As I say, it is more complex than that because output is lessened as the load increases, but the rule of thumb to give you a ballpark idea for no load conversion as I remember it from my college days is: average out in DC is 0.637 of the AC input.
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The "voltage" of a full-wave rectified output is it's RMS (root mean square) value which is the mean value of the AC voltage (Vrms=Vmean / square root of 2) and then you eliminate the approximate 1.2v loss for the two diodes conducting at any given time.

The "DC" coming from the bridge rectifier is approximately 20.01 volts with a 30 volt RMS input. Knowing whether your meter's AC ranges are reading RMS or Peak-to-Peak is helpful. In the US, if reading about 120v from a wall socket, it is reading RMS if it's around 177v, it's Peak-To-Peak (most are RMS). If you read an open circuit bridge rectifier, you're not getting an accurate DC reading since there is nothing to smooth out the voltage bumps.

See post 44 by cosmos here: https://www.accessnorton.com/NortonCommando/capacitor.29600/page-3 especially the attachment at the bottoms to see what the DC actually looks like when no battery or capacitor is connected.
 
I was reading on https://www.roadstercycle.com/index.htm that the Shindengen units dump excess just like the zener diode. It is the opinion of that particular vendor that beefing up the charging system and then moving to LED lights and other low amperage features will shorten the life of the regulator unit due to the excess heat.


From the above site:

"What is a balanced charging system?

A balanced charging system is when the manufacturer designs lets say 25 amp charging system and the bike uses 20 to 22 amps of it to run the bike and charge the battery. The R/R only needs to get rid of 3 or so amps, so it is happy. Now if you take that same bike and run led taillights and marker lights and maybe some led headlights now your making the R/R get rid of lets say 10 amps, now its working hard and getting hot. Although it seems like your doing your bike a favor by thinking it's going to charge your battery better your actually slowly killing your R/R. Not to mention if you unplug your headlights for track days. Wow!!!!"
 
This one ain't gonna burn out on a Commando:

30 amps, 10 gauge wires -

How many Ah for my 1974 Commando?


https://www.ebay.com/itm/SHINDENGEN...rentrq:253f2ccd1700a9e53843c811ffe32427|iid:1
 
Gotta be careful on those Shindengen units as there are many listings that are knock offs. Do some research and review the ways to determine knock off vs authentics. Usually a hint is a price point about half that of authentic.
 
KNorton said:
That was my point previously.
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Which is exactly why I posted the information I found. I came across that web site because the vendor does a video on YouTube explaining how to tell an authentic unit from a knock-off. There is a lot of good information there. While it may not shed light on why some lithium batteries survive and some don't, it seemed pertinent to at least some of the conversation here.
 
I appreciate the concept of the higher tech regulators BUT in the reality of running a stock Norton I don't see any actual advantage in operation UNLESS they provide higher voltage at low/idle speed. As far as reliability, my Norton had the OEM charging system from 1973 until 2012 with nary a hiccup. ;) I replaced the regulator/rectifier with Podtronics when I installed the Alton E-start/Alton Alternator because I thought I should. But there was no "improvement" in charging/maintaining the battery at low/idle RPM.

I had always thought it was the alternator that limited low speed charging, not the regulator...
 
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MexicoMike said:
I had always thought it was the alternator that limited low speed charging, not the regulator...
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Yes, though the regulator circuitry can certainly introduce losses. For single phase nothing beats a zener at low rpm.
 
Interesting and it would explain why the Lucas ref/rect/Zener actually produced almost .2 volt more at idle than the Podtronics did with the same alternator. But I still went ahead with the Pod because...well because it's modern and an "upgrade." Like many modern "upgrades" for these bikes, performance-wise, it isn't. It's just a more convenient package. ;)
 
Tornado said:
Gotta be careful on those Shindengen units as there are many listings that are knock offs. Do some research and review the ways to determine knock off vs authentics. Usually a hint is a price point about half that of authentic.
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The one I linked is the real deal. The 3 key points are the round bosses cast into the fins, the Shindengen logo and part number on the back, and a stainless bottom plate. Knock offs only show a top view, not the back and bottom.
 
MexicoMike said:
Interesting and it would explain why the Lucas ref/rect/Zener actually produced almost .2 volt more at idle than the Podtronics did with the same alternator. But I still went ahead with the Pod because...well because it's modern and an "upgrade." Like many modern "upgrades" for these bikes, performance-wise, it isn't. It's just a more convenient package. ;)
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Seems to me that leaving the charging system stock but moving to LED lights is a viable option. Not many years ago LED lights were expensive but not so much these days. The items needed for DYI are also readily available now. My 5 Ah AGM battery (getting back to the original question in this thread) is happy now on the stock charging system. But admittedly I run a low wattage headlight. This is where the LED would shine!
 
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