Charging System Upgrade

Snakeoil · Post by **Snakeoil** » Tue Jan 04, 2011 9:50 pm

I've done a search and read all the threads that talk about charging system upgrade, specifically the stator and regulator/rectifier upgrade from Rick's Motorsports. What I could not find is a definitive answer if this upgrade is truly needed.

Some have taken measurements that show a 2 to 4 amp drain on the battery (lights on/off) at speed. Others have indicated that they show positive voltage above the battery voltage and have never drained their battery.

My bike is a 1967 CL77. I understand that the system is an unregulated system that runs at a low power with lights off and full power with lights on. But I am led to believe it is not sufficient to charge the battery while running at speed with the lights on.

I need to study the system, so I may be asking these prematurely, but I'll ask them anyway.

Here are my questions.

Can the existing system be modified to run full power all the time and a regulator added to prevent overcharging the battery? Has anyone tried this?

Are the problems some have with dying batteries due to a tired system (weak magnets or worn/damaged stator windings)?

Has anyone tried rewinding and OEM stator for more output?

One post indicated that the power from the system is a function of the amount of copper in the windings and the strength of the magnets (flux) in the rotor. I see there is an old rotor from a CL72 that has stronger magnets but aparently was discontinued because it overcharged batteries. Has anyone used that rotor and added a regulator to provide adequate charging?

Thanks,
Rob

Wilf · Post by **Wilf** » Wed Jan 05, 2011 9:29 am

Rob,

I think Rick's conversion runs full power all the time with a regulator.

Some of the problems with dying batteries are a result of poor connections and aging selenium rectifiers. Stator windings can vibrate against each other if the tape is gone. That could lead to shorted turns and less voltage. Weak magnets will reduce the power output.

Rewinding the stator has limitations: to get a higher voltage you need more turns in each coil and that means using smaller gauge wire which increases the coil resistance and that reduces the current ouput. What you gain in voltage you must lose in current.

Simple voltage regulators need a higher initial voltage and dump (shunt) current to ground to bring the voltage down to the regulated level. You need more to start with because it robs the system.

Three things can be easily done to optimize the stock system: clean all terminals; use a modern silicon rectifier; convert brake/stop light, winkers and neutral light to led's.

Wilf

Snakeoil · Post by **Snakeoil** » Wed Jan 05, 2011 10:31 am

Thanks Wilf. After posting my inquiry, I read the charging system portion of Bill Silver's book and he pretty much says the same thing. I guess if you let the bike idle in the driveway with the lights on all day, you'll kill your battery.

I did the rectifier mod on my S90 last year so I'm familiar with that mod. I actually bought a little better rectifier of the same physical size as the Radio Shack unit from a the same guy I got my Ohmite rheostat from last week. I'll have to go get another. I'd been meaning to do that mod and will definitely do it this winter.

I have a spare stator and rotor from a '65 engine I got with my bike. I guess I should take a look to see if it has an L on the rotor.

NYS requires headlights on at all times. Although you can probably get away with running a vintage bike with the headlight off. I know I forget to turn the Bonnie light on almost as often as I forget to shut it off.

No winkers so LED tail/stop light will go on the TO-DO list along with the rectifier.

Thanks and regards,
Rob

e3steve · Post by **e3steve** » Wed Jan 05, 2011 12:08 pm

With no e-starter, you should have only a 4Ah battery on a CL I believe, Rob. This may demand the lo-output rotor stamped CB72(L). Have you ever managed to flatten the battery low enough to stop the bike from starting easily? If not then I'd leave well alone, aside from replacing the rectifier.

A simple health check on your system requires just a Digital MultiMeter; at the battery terminals you should be able to observe between 13.5 & 14ish VDC, engine running 'n' revving (4000+ rpm), lights off/lights on.

The big problems with the old selenium recs is heat and/or diode breakdown. The latter will flatten a battery and/or cause a bit of a smoky burnout with the rec's wiring.

Spargett · Post by **Spargett** » Sat Jan 29, 2011 2:37 am

I installed Rick's aftermarket stator, and I already had a new rectifier installed. I did so mostly so I could run a stronger H4 headlight (55w/60w). The other nice thing is that his charging system is a single phase solid state unit.

That's saved me before when my battery died on me deep in the Tahoe National Forest. The cause was due to a combination of old worn out (poorly performing carbs), low oxygen altitude, steep hill climb, all that left me in a low RPM purgatory between gears for the majority of the climb up the mountain with my headlight on. I hadn't really realized it until I pulled over for a second to take a break and the bike wouldn't start again. After a number of desperate kicks, it was enough to start again (single phase) and I was off. By the time I got to the destination in South Lake Tahoe, the battery was charged again.

I've covered thousands of miles on this bike, across every kind of terrain all throughout the seasons. And I have to say, for all the quirks and and annoyances that come up here and there, she's never left me stranded. Not once. Always made it "home".

So to summarize, it's a great upgrade if you really plan on riding your bike and can afford the investment. ($225). If you've already got the rectifier, the stator is only around $100.

brewsky · Post by **brewsky** » Sat Jan 29, 2011 5:31 am

The Dream owners manual actually says you can charge the battery by running lights on and dimmer switch in neutral position. Don't know about CB or CL manuals.

Problem is, not all switches have the middle neutral position available.

The parts book shows a superceeded number, but no vin break.

I even took mine apart looking for it, thinking it was gummed up with crud, but it wasn't there.

An extra spring did fall out however, which obviously didn't belong....wonder where it is supposed to be?

cyclon36 · Post by **cyclon36** » Wed Mar 09, 2011 10:59 pm

in case anybody is interested, a high output rotor is on ebay at the moment for a decent buy it now price: http://cgi.ebay.com/ebaymotors/Alternat ... 902wt_1165