Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board Podtronics Rec/Reg

I think the whole earth thing has added confusion to you.

Try think of it more as a simple circuit. One your bike the frame acts as part of the circuit on the return side to the battery (electron flows negative to positive) so whether it be the reg rec or the battery tender lead, the red always goes to red at the battery and the black always goes to the negative. Depending on whether you have an ammeter or not determines on whether your regrec can connect directly to the battery or the other side of the ammeter to the battery.

I’ve tried starting bikes up when they are on an opti-mate before now, usually the optimate just cuts out until you unplug and plug it back in again. It hasn’t damaged the optimate, the battery or the reg/rec. what I have had is where the battery has been fitted the wrong way around and this has blown the fuse when the revs have picked up. (But because of the fuse saving the day it hasn’t caused further problems)

I'm never had issues with my battery tender. It charges like all other vehicles, shuts off when complete, doesn't harm anything.

The only gotcha is the little plastic cap over the battery Tender connector that's hooked to my battery. The exposed pin is Bat Neg which isn't an issue on a negative ground vehicle. On the BSA however, I always make sure I replace that cap when I disconnect the tender, lest it should touch the frame.

I should have put the 'normally goes to frame[' in brackets mate. I was just stating that the batt+ is normally connected to frame.
Not to actually connect the reg + there.

Nick

No.

Well got the Podtronics installed ready to go.

Turns out my alternator stator is toast.

Ordered this one-

https://www.feked.com/alternator-stator-genuine-lucas-47239-single-phase-12v-high-output.html

Any comments?

Thank you,
SteveG

How did you determine the stator has an issue? Was the Podtronic fine all along? And what about your battery that is "toast"? How did you get that?

That stator will work fine. It’s a shame you didn’t know this before, you could have bought a 3 phase high output stator and regrec and never had another battery issue again. The nice thing with the 3 phase kit is you reach max output at 2000-3000 revs, with single phase I believe max output is something like 5000+ so unless your giving it some you don’t always meet max charging capacity. However you should still be fine with the RM23 which you’ve linked there. It’s still better than stock.

I believe I said the stator was "toast" not the battery. Small misunderstanding- No worries.

Installed the new Pod. and the battery is still not receiving any charge.

Pulled the primary cover and discovered the insulation on the wires deteriorated and bare wires were touching..

In the beginning, I thought the stator was good because I got a 3 ohm reading from the stator wires. My mistake.

The was reg.was, and probably still is good.

So now I have a new reg. and soon a new stator.
.
Time will tell if these changes solve the charging problem when I receive the stator and install it.

Will post the results

Thank you.

SteveG.

Seeing as you ask, the stators sold as “genuine Lucas” are said not to be the best ones.

Can you not just re-insulate them?

Hi Steve,
Nope, no different. Electrons go the same way 'round any DC circuit; "ground" is an imaginary concept, nothing to do with Physics.

The only reason you'd experience difficulty is if you didn't connect the battery Tender leads to the actual battery terminals, you were connecting either BT -ve or +ve lead to somewhere else on the bike.

Curious ... suggests the alternator was working and the BT doesn't have any protection against being connected the wrong way 'round (which is effectively what starting the bike's engine/alternator did)?

+1; protection against being connected the wrong way 'round.

Perhaps better asking for comments before you ordered it? Since you asked:-

. Several previous posts from people who bought and fitted them say they don't give any more power at low rpm than standard RM21.

. Those particular Wassell pattern stators are available in the US, curious why you'd order from GB?

. Otoh, available from another British dealer are original Lucas RM23 stators, that do make more power than RM21 at all rpm, for less money than Feked have relieved you of.

Not so.

All alternators generate more with increasing rotor rpm just, at higher rpm, for the same given rpm increase, the Amps increase is less.

5,000 rpm was just a comparison point 'original Lucas' happened to choose. Afaik, Wassell Lucas haven't ever published rpm/Amps plots for any of their pattern stators.

'Original Lucas' rated both the aforementioned RM23 and the RM24 high-output 3-phase for 14.5A @ 5,000 rpm, but the 3-phase's output increases faster at lower rpm - 'original Lucas' advertised 75% of rated @ 2,400 rpm for a single-phase like the RM23, but 85% of rated @ 2,400 rpm for a RM24 3-phase; i.e. a gnat's under 11A from the RM23 but over 12A from the RM24.

Hth.

Regards,

Hi Nick,
I suspected that was what you meant, more making sure Steve was clear as well.

Regards,

Stuart:
“. Several previous posts from people who bought and fitted them say they don't give any more power at low rpm than standard RM21.”

I was wondering if you have anything more rigorous than anecdotal evidence for this comment?

The power curve at low rpm between an RM21 and original RM23 will only differ very slightly. It would require accurate measuring instruments and good experimental method to graph this small difference, and also to show any difference with the “genuine” Lucas RM23 at this low rpm part of the curve.

I very much doubt that anyone without such equipment/technique could convincingly discern the difference between any of the above mentioned stators at low rpm.
The differences will of course be much more obvious at high rpm with ordinary ammeter/voltmeter.

If low rpm performance is of importance, which I think it is for ordinary road-bike bigger twin users, the best (Lucas) answer I agree is the high output RM24.

Some years ago i was asked to provide a regulator for PM alternators the application
was for small wind turbines. I had been making a couple of different units for bikes for
awhile and word gets around etc. The stator winding for these devices was really nicely
wound and had an air gap of around 2.5 thou, these were very efficient devices, they
would give around 25a @ 48v for large battery charging. When i first agreed to take on
the project i didn't realise the overall complexity of what was required and the job grew
considerably. The use of shunt style unit on these was not really so straightforward as
when the unit was shunted to control output the coupling on the stator was so good that
the braking effect would shear the drive gear system. The original unit ended up with
several stages of control and worked out at around 3 times the predicted price, consequently
i only ever built a few.
It's a digression i know, sorry. I also worked with a guy who repaired and rebuilt alternators
here, he wanted to reproduce a package to replace the Lucas rm 19-21-23-24 with his new
setup. He had a great reputation for mag/dyn/alternator winding and had done a lot of work
on the project already. He had heaps of test notes regarding windings wire gauge etc on
Lucas and his version of stators. The project was never pursued as the higher output of his
upgrade forced the use of a regulator and many customers would not want to pay the extra.
This was around 18 years ago now and since then the chap has died. Shame, but at that
time we had a very good setup that would provide a comfortable 15a @ 3500 RPM. We just
needed orders for 200 at a time for it to be worth while.

Hi Dave,
Nope:-
... 'original Lucas' rated the RM21 for 10.5A @ 5,000 rpm and, as I say, the RM23 for 14.5A @ 5,000 rpm; 75% is 7.875 Amps and 10.875 Amps respectively, an extra 3A at low rpm is a bit more than "differ very slightly" on these old heaps.

Hth.

Regards,

Interesting stuff NickL Was it gonna be a potted stator? Presumably using an existing (std Lucas rotor?)
The [email protected] rpm seems like it may have been a bit more powerful than the RM24. Was it 3-phase?

Its a very interesting digression, and one worth knowing about! Thanks, I'm glad folk do this sort of stuff.

Hi Stuart -

You said - ". Otoh, available from another British dealer are original Lucas RM23 stators, that do make more power than RM21 at all rpm, for less money than Feked have relieved you of."

I checked around for the Lucas RM-23 at other dealers and found them even more expensive. The cost with 2 grommets and freight to the US. came to $116 with Feked.
I could not find any dealer, in any country, less expensive, but I only checked about 6 places.

I receive great service from all the dealers I have dealt with, but this time I went with the lowest price, with the same product available. Old Brit parts is a very competitive market, as you know.

So, with all help I've been given, I'll wait 'till I receive the stator and see how everything works out.

Thank you all,
SteveG

Hi Stuart,
I concur with your statement:
“... 'original Lucas' rated the RM21 for 10.5A @ 5,000 rpm and, as I say, the RM23 for 14.5A @ 5,000 rpm; 75% is 7.875 Amps and 10.875 Amps respectively, an extra 3A at low rpm is a bit more than "differ very slightly" on these old heaps.”

You are however, placing much faith in the advertised figures. I agree that is all we have to go on, till we know better.
Promotional ads from Lucas in ~1980 did suggest that the 3-phase system would solve all my issues (which it did).

My situation was a pre-unit with failed magneto. Mistral mag replacement system with Rita sorted that for 30 years. But the new installed RM21 I found inadequate for the demands. So I went to the high output RM24 with 2 Zeners kit from Mistral. I ran this for several years with the Rita and no battery with no problem (no capacitor). It went to Morocco and back like that in 1984.

Since then I have run a battery, and have changed to Boyer IV. It works well (Boyer III it worked well too).

Never known of these low voltage issues, but I also make high quality bespoke harnesses, as yourself.

Used Lucas rotor, stator was going to be potted test/trial unit wasn't. A '6 phase' arrangement as i remember.

" A '6 phase' arrangement as i remember."
Blimey, how does that happen? 6 pole rotor (normal) presumably the stator will have 6 wires and require 2 3-phase reg/recs?
Or have I lost the thread?

Not as complicated as you think really, just look at it as 2 x 3 phase setups common output.
The stator was staggered with 2 x 3 phase sets of windings. It was a bit larger.
As we used decent winding wire the regulator was a combination of series and shunt. We didn't have
the problem of insulation breakdown associated with series setups and windings going open circuit
generating huge spikes.

I believe the RM24 uses 9 poles, as opposed to 6 for the single-phase stators.
It would be interesting to build a test rig, similar to the one used to test Zener diodes, to compare current and voltage output at different RPM.
My only comparison came when I installed an RM24 on my A65. The voltage measured at the battery goes to 14V at a little over 2000RPM. I no longer need to ride five miles after a short trip to the store just to recharge the battery.

Not if you sathese wires!
Bare going into the sator.

Holy cow. Did I write that!
Let me translate:

Not if you saw these wires!
Bare going into stator

That's somewhat better......

SteveG
.

I thought you were typing with a Yorkshire dialect

Liquid tape is perfect for these areas