Biting the bullet on charging system

I haven't been riding much this year due to needing to charge my battery after or before a ride, and now that's not enough since the battery is worn out --- it's embarrassing pushing it off the road and frantically kicking it after dying at busy traffic lights! (one of those times its good to have a helmet on) I last replaced the rotor way back when I was just out of high school, say about 42 years ago, so that clearly is overdue, "my bad". (Headlight on, I'm discharging until above about 2500-3000 rpm)

Is it likely that my low output stator is on borrowed time as well? The bike has only about 22,000 miles, having been stored in my garage for about 35 years. My Commando is kick start only, boyer ignition w/twin 6 volt coils, and original lighting. It seems to me that if I replace the rotor and replace my lights with LEDs (perhaps Paul Goff's), add a modern regulator (e.g boyer or podtronics), and get a decent AGM battery, then the original feeble 140W output might be fine (or would it?). I have lots of traffic lights before I get to either countryside or highways. On the other hand, if the stator will still be anemic even with the other changes, OR if it's likely to be near its end of life anyway, then I'll upgrade the stator as well while I'm at it. In that case, high output single phase or three phase???

I just want a trouble free system that has some margin for degradation, and I don't want to fuss with nursing it along to keep the spark-o-matic firing. I want it to be at least power neutral at idle, lights on (if replaced with LEDs). Is that beyond a 140W stator capability??

Thanks for experienced thoughts!

Ted

I put very little demand on my charging system.That said, I have a reverse philosophy to most on this site. I prefer to run the biggest battery with the most amp hours possible in the space provided. With the new fiberglass mat technology, I just replaced my lead acid battery (a 16 I believe)with one that has even more capacity (an 18 I believe). I checked my records but it did not specify what I bought. Anyway, just a thought. Take measurements of you battery space and get the highest capacity battery that will fit in the space. Such a battery will handle the slow speed discharge and catch back up once underway.

I have an early Commando stator in my Atlas, probably no more than 140W. With a 12 V sealed beam headlight and a 1056 dual element stop/tail lamp, i had to exceed 3K rpm to get the ammeter on the positive side.

I changed to a Paul Geoff LED H4 main lamp, a LED stop/tail, and a 9mm bayonet base LED in each clock. Now the ammeter goes positive at 2K rpm.

I would change over to LED's before giving up on your rotor and stator. My rotor and stator are both approaching 50 years in age, and I have not detected any drop in performance.

Installing a Podtronics or other modern rectifier/regulator would be a definite plus.

Slick

you might have some electrical loses in bad wiring connections.

Start with a new rotor (the magnets do weaken with age, and you have already identified it as a potential issue).
Also treat yourself to a decent new battery (I suggest the Motobatt AGM - as this will excel at occasional use, winter lay-up and trickle charging).
Then see how you get on.

The stator, zener and rectifier don’t go bad (degrade) - they’ll just fail (stop working), so leave them where they are for now.

Put a multimeter across your new battery once it’s on the bike and see what you’ve got at idle and at revs - that will determine if you need to dig deeper and spend more.

I've recently been through a similar conundrum. I have the RGM LED charge warning light and I was at 4000 rpm before it was going out with headlamp (H4 60/55W) on. I bit the bullet and went for a three phase kit.

But, when I fitted it I checked the magnetism of the rotor against the new one - how much weight could it hold - I couldn't see a difference between new and old. So I fitted the new stator and rectifier and left the old rotor on. The old rotor is stamped 1973.

I'd suggest you change the battery and do some wiring checks, plus consider LED bulbs before you spend the money on new rotors, stators etc.

Having said that I'm happy with the 3 phase as mine is now charging fine. Bought mine from Andover.

I wouldn't mess with anything at all until you install a new battery/check all connections to ensure no bad/corroded ones, and then do some voltage checks at various RPM to see what the readings are. Proceed from that point.

I run the original single phase alt., bridge rectifier, and zener. Halogen headlight (that is on at ALL TIMES) (45W/45W) and AGM battery, Boyer ignition. The electrical system performs perfectly.

Have you replaced all the female snap (bullet) connectors?

Get the voltmeter, get some readings, report back.

Test, don’t guess.

It depends on what kind of riding you do.

My buddy runs a stock system too, but doesn't do much night riding and doesn't use lights during the day.

My stock system worked OK until I installed a 60/65 watt H4 halogen headlight, which would dim at idle. I upgraded to a 210 watt 3 phase charging system and that problem went away. I also installed a 20 watt halogen pilot lamp that I used for daytime running light.

Recently I installed an e-start kit and Li battery. Most of my riding is under 3000 rpm and I'm finding that the battery goes flat after a week in the garage unless I keep it on a maintenance charger. Will be switching to all LED's this weekend and installing a voltmeter to keep an eye on it before making any further decisions.

Three things that will screw up your charging ability. Corrosion, loose connections and shorts. All of them require patience and a good examination of the wiring loom. Maybe some new wrap on the loom while you are at it, if its original the tape is probably brittle and a hindrance. The keyed ignition switch can be a corroded mess inside and cause a loss of voltage. Checking voltage before and after the switch will help identify this.

My 74 850 has original charging system. I'm running the BPF format led headlight ($35) led pilot light and led light board brake/taillight.
I have a Sparkbright charge indicator led in the old assimilator lamp place. No assimilator and wassel EI
Battery charge state has not been an issue on a standard sealed lead acid. Sparkbright shows low volts up to around 2K. At 3 to 4K or more, it shows a high voltage warning which means 15+v even with lamp on. Might be the zener can't handle the extra power due to lower consumption rate from leds. So far this hasn't affected battery but it's only a year old. Why is it the mkiii bikes run two zeners? Is it to better handle over voltage?

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

maylar said:

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

Click to expand...

So if running lower consumption lights like LEDs would the single zener be doing excessively high dumping to ground to deal with the unused power?

Best thing to do is go through the whole wiring system, remember our Norton's are getting old wiring gets brittle, connectors get corroded, wires break, then open up your primary case and look at what state your rota and stator are in, make sure the leads from the stator are still in good condition as the wires go hard and brittle from the heat, pull the stator off and make sure the windings are still all good, a good multie meter is your best friend, test your battery when running to see if its charging at different revs you need to have at lease 13.5 volts to keep the battery charged as well get your battery load tested, even near new batteries can fail.
I run a Joe Hunt Maggie on my Norton and don't need power to run my bike, I don't use my head light during the day and I no longer ride my Norton at night but I do run my lights off a very small battery when I do need to use them, I was running my bike through a battery elimiator before putting the small battery in just for my brake light, I have very min. wiring system on my bike, less wiring mean less troubles.
Test things before replacing everything, the stock system will work well if its in good condition, but as our bikes age things do play up and things do need to be replaced, maintenance is very important and your wiring and charging system should be part of your annual maintenance, not just a oil change.

Ashley

Looks like I need to do some of the above. Went out on long ride today. First kick starting as is the norm for my bike. After a fuel up, no start. Then discovered no lights. No electrics at all. Fuse good (I have modern mini fuse with a holder that has a warning led when it blows). Could not see any disconnects and gave ignition switch and other major connections a good wiggle. Power came back. Bike started and after a bit of riding around block looked solid. Off I went on long ride. All good. Hours later after coffee stop again no electrics. More poking about and wiggle I found the fuse lead crimp to the brown blue harness lead pulled out. So absolutely no battery. Curiously I did have my sparkbright and pilot lights working in this state must be the good old 2 MC capacitor still doing its best. jammed the disconnected wire. Back into the crimp and hoped it would get me home, but found still no lights. battery must be dead. Tried to kick her and she fired second try. So now I know the wassell ei can start sans battery. Using non led turn signals caused the pilot to blink dim so I knew volts were marginal.

Got it home ok. Battery shows no more than 12v. Soldered the bad connection. Now charging on the trickle. I inspected the battery and there may be some bloating on the side panels, possibly from over heating from a poorly working zener. I'll see what next few days brings.

Tornado said:

So if running lower consumption lights like LEDs would the single zener be doing excessively high dumping to ground to deal with the unused power?

Click to expand...

No worse than no lights at all. It's sized for that.

Ted here's what I did 32,000 miles ago after going through the same thought process as you.
1) I ditched the 40+ year old bullet connectors and soldered all of the wires together. I know that many disagree with this fix reasoning that the joints are too rigid and will ultimately break. On my bike the area with all of the solder joints is secured to the frame with cable ties to prevent flexing. 5 1/2 years and no issues with the wires.
2) I ran many new extra ground wires.
3) I cleaned all of the contacts in my ignition switch and put a light coating of dielectric grease on them. I did the same with the handlebar switches.
4) A new OEM size AGM Motobatt battery with a new fuse holder.
I run an older Boyer ignition (40K+ miles on it), a 50/55W sealed beam headlight, OEM style tail light, Podtronics voltage regulator, and the 1973 original stator and rotor. I've had absolutely zero charging problems with these changes. I've also never had to cut any of my solder joints for repairs which was one of my main concerns about the solder joint.
The Norton charging system is very simple and fairly reliable so there's no need to over think it. Good luck

Tornado said:

So if running lower consumption lights like LEDs would the single zener be doing excessively high dumping to ground to deal with the unused power?

Click to expand...

The power output of the alternator has to go somewhere ..... If not to the demands of the lights, then the Zener must sink it. If the excess power exceeds the Zener's capacity to sink it, the battery must absorb any "overflow" power, in which case, the battery and lighting life will be shortened, due to high voltage (over 15v).

Thus, it is unwise to retro fit an alternator with significantly greater power than originally fitted, unless one has retro fitted additional electrical loads.

Most rectifier/regulators like the Podtronics, for example, sink excess power, so such regulators do not get around the problem. There are regulators that pass only the power required by turning the stator on and off (like a switching power supply). Do a search on regulators with the author "jeandr". He did a very nice treatise on regulators.

Slick

Tornado said:

So if running lower consumption lights like LEDs would the single zener be doing excessively high dumping to ground to deal with the unused power?

Click to expand...

The Mk 3 alternator system uses a half-wave rectifier rather than the full-wave rectifier of the earlier systems, so it splits the load of each set of (3) coils and uses a zener diode to regulate the output of each of the two sets of coils.

Thanks for all the responses! To be fully honest, I haven't fully checked connections, since I have pretty much always had what I considered insufficient output since I bought the bike in about '74. Just that now it's consistently worse. So connections do deserve to be checked, but I suspect bad connections are at most a contributor, not root cause, based on the fact that many of the responses are based on not running lights or compensating for shortfalls with extra battery capacity. So I doubt the original system with incandescent lights will ever reach my desired goal of being able to idle long term with minimal discharge. (By the way, the very first "real" motorcycle I owned --I suppose some purists might debate the term "real"-- was a '68 Suzuki 200cc twin road bike. That bike could idle all day, headlight on, and never go dead as I recall. I think I put about 25k miles on that little squawker)

So, my order of business will be, check connections and install a new battery (since that is known to be shot). Take some voltage data at various rpms for baseline. IF no smoking gun is found on connections, replace rotor. Take comparison data. Replace lights with LEDs and see how it does with LEDs. I suspect that might be enough to be workable for me, if not ideal. If not good enough, I'll probably go to the three phase with upgraded regulator, since I don't want to replace anything twice, and the 3 phase plus regulator is not "that" much more than the upgraded single phase, unless somebody can definitively say the single phase output is more at idle.

Incidently, I sent an email to Boyer and asked if their regulator is a "switching type" to control voltage, rather than a "dump to ground" type like our old zeners. Without a lot of detail, they said it electronically switches off for control. (Slick--I'll also look back at the "jeandr" posts to see how the other brands function.) Thus, it's more efficient and wouldn't generate as much heat as a zener. Now, whether it clips the waveform (which would be the way I would expect), or "cycles" on and off quickly (possible but probably unlikely) they didn't say. However, either way would only allow the needed current to flow. I would think this form of regulation would be more precise (longer battery life) and also result in a little longer rotor life, since there would be less net opposing magnetic field set up in the stator. (???) It would certainly also use a little less shaft horsepower, but that's hardly worth the mention.

It'll be a while before I report back, since I'll need to buy some stuff.

Thanks again.

Ted