Charging issues? or has the battery had it?

Hi all,

I'm currently trying to diagnose a charging problem that's been made apparent by conking out in the dark at 8pm the other night! Fortunately I was only 1/2 mile from home so did the last bit without lights.

As the ride went on she started to run rough, I have Boyer Bransden electronic ignition & a BB Power Box, which I know don't like a weak spark, so I knew something was amiss.

I also spotted that my charging light goes out instantly when I kick her over. I've got a SparkBright battery monitor on its way which will tell me a bit more.

I realised that I'd doubled up on zener diodes as I'd connected the one on the z-plate. The Power Box has one built in, so I've removed the original one but left the earth there. I don't think it would've done any harm but it's ruled it out.

Battery is an Exide AGM YT12A-BS 12V 9.5Ah. Not the foggiest when it was bought & fitted.

I've done a few (limited with my knowledge) tests this morning & this is what I found.

- Battery just off trickle charge: 13.54V
- Idle/no ancillaries: 12.82V
- ~3KRPM/no ancillaries: 12.10V
- ~3KRPM/ancillaries: 12.10V

- There's continuity between the alternator leads
- At ~3kRPM there's 34VAC from the alternator (measured between 1 lead & yellow to the Power Box)

Charging issue. Even (most) a failed battery will come up while charging.

Sounds like your power box may be playing up. you should be seeing around 14V at the battery at 3000 revs without headlights on.
If you still have your zener on the Z plate why not replace the power box with an inexpensive bridge rectifier and re connect the zener.
Some times the old technology can be more reliable.

Oh no! I thought we'd got this one fixed?

It's worth following through the diagram i made you all those months ago, and making sure everything is in the right place.

Custom Norton Commando Wiring Diagram – Luke Turner

I think we discussed on your Facebook post back then the importance of not have the original zener connected or the original assimilator.
If the factory zener leaks to ground before the trigger point of your Boyer Bransden Power Box, then the Power Box won't get enough juice to do it's job. It sounds like that's what's been happening with you.
Boyer call out in their documentation, that the factory assimilator must be disconnected - that because it takes a feed on the AC side (ie from the alternator) which can adversely affect how their Regulator/Rectifier operates.

• The fact your AGM battery is at 13.54v after a charge is good - it probably means your battery is not kaput. AGM batteries usually recover well from a full discharge.
• Your 12.8v at idle is as expected, so nothing to worry about there - with a single phase alternator, you will be typically taking out more than you're putting back at idle.
• Your 34v AC at 3,000rpm is good too - says to me that your alternator stator and rotor are working well.
• But the 12.1v DC at 3,000rpm is cause for concern - that says nothing is getting to the battery from your Boyer Power Box.

When you say you have removed the zener, but left the earth there, what do you mean?
The earth is the diode screwed into the z-plate.
You need to disconnect the Brown/Blue that goes to the zener, and make sure it's securely taped up so it can't touch your frame (if it does, you'll blow the fuse).

As i said before - make sure the original assimilaor it disconnected - there are three pins
Brown/White which you have already re-routed for your warning light
The earth (ie +ve to the frame)
The Green/Yellow to the alternator (this is the most important one to disconnect)


I would be inclined to test your Power Box and make sure it's not kaput - i remember this is your second one?



To test the rectifier side (the part inside the Power Box that converts AC from the Alternator to DC which charges the battery:

Set your multimeter to continuity or resistance (when you cross the positive and negative leads, your meter will beep or read zero)

Test One

• Attach your red multimeter lead to the red lead of the regulator/rectifier
• Attach the black multimeter lead to one of the yellow leads of the regulator/rectifier
• Your multimeter should not beep, or give any reading
• Do the same for the second yellow lead

Test Two

• Attach your black multimeter lead to the red lead of the regulator/rectifier
• Attach the red multimeter lead to one of the yellow leads of the regulator/rectifier
• Your multimeter should beep, or give a reading - write down the value on a piece of paper
• Do the same for the second yellow lead - write down the value each time

Test Three

• Attach your black multimeter lead to the black lead of the regulator/rectifier
• Attach the red multimeter lead to one of the yellow leads of the regulator/rectifier
• Your multimeter should not beep, or give any reading
• Do the same for the second yellow lead

Test Four

• Attach your red multimeter lead to the black lead of the regulator/rectifier
• Attach the black multimeter lead to one of the yellow leads of the regulator/rectifier
• Your multimeter should beep, or give a reading - write down the value on a piece of paper
• Do the same for the second yellow lead - write down the value each time

All of the values above zero that you have written down should be more or less the same.

If there are any wildly different numbers, it signifies a fault with one of the diodes. This is not serviceable, so the unit must be thrown away - don't put it in a box in the garage, as in twenty years time you may pick it up and put it on a bike.

I have a similar problem, even down to same make of battery. Thanks gtiller I have been putting off fixing this cause the bike (Pazon ignition) has been running fine these long summer days. I also have a led battery charge indicator and powerbox

@Steves the Pazon Sure-Fire isn’t quite as fussy as the Boyer Bransden electronic ignition.

It will work at 10 volts quite happily.

Shout if you get stuck

gtiller said:

When you say you have removed the zener, but left the earth there, what do you mean?

Click to expand...

I expect it's the (double) red wire that attaches to the inside of the Z-plate adjacent to the Zener which under normal circumstances would be the actual Zener earth.

gtiller said:

The earth is the diode screwed into the z-plate.

Click to expand...

Not exactly, the Z-plate is only intermediate as the red wire is the Zener earth.

gtiller said:

The earth (ie +ve to the frame)

Click to expand...

''Earth' is the system of red wires running throughout the harness and ultimately connects to the battery positive terminal.

You can't have too many earths on these bikes!

...unless you've got an electric start of course, but that's a whole different story!

gtiller said:

@Steves the Pazon Sure-Fire isn’t quite as fussy as the Boyer Bransden electronic ignition.

It will work at 10 volts quite happily.

Shout if you get stuck

Click to expand...

Probably why I have been running around quite happily all summer with a poor alternator . More pressing problems on another bike at the moment. Thanks for the offer almost certain to get in touch for advice.

gtiller said:

Oh no! I thought we'd got this one fixed?

Click to expand...

We did, for a short while!

gtiller said:

I think we discussed on your Facebook post back then the importance of not have the original zener connected or the original assimilator.

If the factory zener leaks to ground before the trigger point of your Boyer Bransden Power Box, then the Power Box won't get enough juice to do it's job. It sounds like that's what's been happening with you.

Boyer call out in their documentation, that the factory assimilator must be disconnected - that because it takes a feed on the AC side (ie from the alternator) which can adversely affect how their Regulator/Rectifier operates.

Click to expand...

I think you're right. I can't see any lose/dodgy connections and as you've confirmed, all my tests give out promising readings, apart from the 12.1v DC at 3k RPM..

gtiller said:

When you say you have removed the zener, but left the earth there, what do you mean?
The earth is the diode screwed into the z-plate.
You need to disconnect the Brown/Blue that goes to the zener, and make sure it's securely taped up so it can't touch your frame (if it does, you'll blow the fuse).

As i said before - make sure the original assimilator it disconnected - there are three pins
Brown/White which you have already re-routed for your warning light
The earth (ie +ve to the frame)
The Green/Yellow to the alternator (this is the most important one to disconnect.

Click to expand...

L.A.B. cleared that up in his reply, it's the double red wire that would be the original zener earth. I've taped up the brown/blue & I shall double check the terminations of those other cables listed, although I'm fairly confident they're all used/safe.

gtiller said:

I would be inclined to test your Power Box and make sure it's not kaput - i remember this is your second one?

Click to expand...

Yes it is! I'll get in the garage tomorrow night & run those tests. I hopefully won't need a 3rd!

Cheers Grant. It's hugely appreciated.

Fitted a SparkBright Eclipse battery voltage monitor which will tell me a bit more about the charging system. It cycles red/amber/green on start up & then goes to steady amber, which whilst the engine isn't running, shows "normal battery, charged and in good health".

gtiller said:

Test One

• Attach your red multimeter lead to the red lead of the regulator/rectifier
• Attach the black multimeter lead to one of the yellow leads of the regulator/rectifier
• Your multimeter should not beep, or give any reading
• Do the same for the second yellow lead

Click to expand...

No continuity ✔

gtiller said:

Test Two

• Attach your black multimeter lead to the red lead of the regulator/rectifier
• Attach the red multimeter lead to one of the yellow leads of the regulator/rectifier
• Your multimeter should beep, or give a reading - write down the value on a piece of paper
• Do the same for the second yellow lead - write down the value each time

Click to expand...

No continuity ✘

gtiller said:

Test Three

• Attach your black multimeter lead to the black lead of the regulator/rectifier
• Attach the red multimeter lead to one of the yellow leads of the regulator/rectifier
• Your multimeter should not beep, or give any reading
• Do the same for the second yellow lead

Click to expand...

No continuity ✔

gtiller said:

Test Four

• Attach your red multimeter lead to the black lead of the regulator/rectifier
• Attach the black multimeter lead to one of the yellow leads of the regulator/rectifier
• Your multimeter should beep, or give a reading - write down the value on a piece of paper
• Do the same for the second yellow lead - write down the value each time

Click to expand...

No continuity ✘

Destination: bin?

Luke Turner said:

Fitted a SparkBright Eclipse battery voltage monitor which will tell me a bit more about the charging system. It cycles red/amber/green on start up & then goes to steady amber, which whilst the engine isn't running, shows "normal battery, charged and in good health".

Click to expand...

What does it do when the engine is running?

You already had posted voltage readings....
No news here.

maylar said:

What does it do when the engine is running?

Click to expand...

Engine off, key 1st pos: Green steady
Engine off, key 2nd pos: Amber steady
Engine running @ idle: Amber steady, then red slow flashing, then red 2 flashes, then red 3 flashes, then red 4 flashes
Engine running @ ~3k rpm: Same as above

I also dug the old alternator stator out of the cupboard & it's got 9 poles, so 3-phase.

I stuck a new single-phase in as I didn't give it a second thought. Seeing as it's died a death, I'm tempted to put a 3-phase (Wassell) back in along with the appropriate Power Box.

https://www.rgmnorton.co.uk/buy/boy...rectifier-for-three-phase-alternator_1885.htm

Am I right in saying I don't need the one with the charging light control as I've fitted a SparkBright? The 3-phase BB Power Box with charging light control is neg earth only. The one without is pos earth.

Do I need to uprate anything else if sticking a 3-phase alternator in?

You might want to consider the much better sh775 reg rec as it does not switch current back into the stator coils when charging volts are exceeded. This should be better for stator longevity esp if you've upgraded to high output and or three phase.
See the informative thread by jeandr on how the pod and bb reg rec work vs the polaris sh775.

That said I 've just bought a more traditional Tympanium reg rec for my otherwise stock stator and rotor. My zener seems to not be holding charge volts under 15.2 v and my sparkbright is giving overcharge warning at 2 or 3k rpm. My battery my now be fried.
Went with this setup as I feel the better reg rec may be overkill for the low output two phase I'm keeping for now added bonus is its a very small footprint compared to others so will be easy to mount also low price point 47 USD from CBS.

Got my 120w Pod. R/R from Walridge motors in Ontario for $49 CAD last week .... sometimes pays to shop around ... nice and small hung via pipe strap from main beam just behind and above battery .... some gorilla tape on beam for scratch protection and good to mount ...

Craig said:

Got my 120w Pod. R/R from Walridge motors in Ontario for $49 CAD last week .... sometimes pays to shop around ... nice and small hung via pipe strap from main beam just behind and above battery .... some gorilla tape on beam for scratch protection and good to mount ...

Click to expand...

That's a good price esp if it's CDN. The tympanium is 200W rating and supposedly put together in USA if that is a benefit?
Shipping was free as long as I used my US mailbox. So needed a jaunt cross border but weather is nice right now.



Thinking to place it where original rec is currently occupying. Does need to be on a flat metal surface for best heat dissipation.

Tornado said :
"Thinking to place it where original rec is currently occupying. Does need to be on a flat metal surface for best heat dissipation"

A flat surface would be best to heat sink it. One can also use a heat sinking "grease" to reduce thermal resistance.

Slick

The oem rec position can work but does require some fettling to use existing holes in the frame cross web. The mudguard bracket interferes enough to either space bracket off the web more with washers so the rr can slip an edge between bracket and web or I'll need to cut a 1/4" thick slab of alloy plate to space the rr off the web and over the guard bracket. Could put it on battery box side of same web but then the side cover bracket would not work.
Now I'm thinking there's good space at left side battery box panel, forward corner. Just needs some rubber padding trimmed away. Another thought is the rear airbox plate battery side (this is the MKII bike with metal ham can not plastic box). Just a couple of small bolts through the plate. Good cooling flow to forward side there. No spacing issues.
Am I correct assuming the old rec connections just need taping up and not connecting to anything else? I can connect new rr direct to stator two wires and then direct to batt positive and through fuse to negative.

Tornado said:

Am I correct assuming the old rec connections just need taping up and not connecting to anything else? I can connect new rr direct to stator two wires and then direct to batt positive and through fuse to negative.

Click to expand...

I am not familiar with the Commando. That said, I would think your existing wires in the harness can be used, if they will reach your intended mounting spot. If they do not reach, why not install some bullets, and lengthen as needed? That is how I mounted my Podtronics RR on my Atlas. I made a flat plate to take out the irregularity of the surface, then connected the RR wires with bullets to my existing harness. Using what is there makes for a cleaner installation, rather than taping up and abandoning.

You will not need the Zener. You can remove the Zener and tape up the wires and leave disconnected, or fold the taped wires back into the harness.

Slick