Topic: A better charging system?

[dustyc]

Is there a way to improve the charging system on our bikes?  I have a '71 CB500, but it seems most SOHCs(or is that all?) are lacking at low revs. 

I'd like the charging system to charge the battery at idle.   

Why did the Honda engineers make the system this way?

[Bodi]

Well, an air cooled engine will overheat quickly if just idling.
Almost all of the time it's running it should be in the "charging" zone above 3000 RPM. If you're cruising at 25mph through school zones in top gear you're abusing the engine. If you don't like the sound of a high revving four cylinder engine, maybe a V-twin is more your ideal engine.
An alternator that will charge at idle is possible, but I don't see it as a design goal for these bikes. One problem is with idling itself. At idle the alternator is putting out all it can, maybe 60 watts or so - about 1/10 horsepower, and it's pretty much continuously at that load when idling as the bike's load is more than 60W with the battery supplying the balance. If it could put out 150 watts, close to 1/4 horsepower, you could idle OK... but when the battery is at full charge the regulator would reduce the alternator power output (and engine load) to compensate and the idle speed would rise immediately. To compensate for that would be complicated - EFI cars have throttle advance motors to keep a constant idle speed regardless of load so the air conditioning compressor or power steering pump don't stall the engine when activated. Older carbureted cars with A/C have a solenoid that bumps the idle up a set amount and you can always hear the engine speed up or lug down slightly when the compressor kicks in. The GL1200 uses a brute force regulator - the alternator always makes full power and "extra" electricity is dumped into heating a resistor. This is partly because of the idle speed issue, knowing that the engine has gobs of power so losing a half horsepower is OK to save the cost of a switching regulator and idle compensator.

[coyotecowboy]

OK, so how would a guy go about getting the charging system to produce more amps at and above 3000 RPM?  I'm thinking enough to run heated grips, maybe a heated jacket liner, a 12 volt jack to run a GPS unit off of....     Any ideas?

[dusterdude]

i would think the stator could be re-wound to put out more amps.

[dustyc]

Almost all of the time it's running it should be in the "charging" zone above 3000 RPM.

Yes, but I find myself sitting in traffic quite a bit which is why I'd like it to charge at idle.

The GL1200 uses a brute force regulator - the alternator always makes full power and "extra" electricity is dumped into heating a resistor. This is partly because of the idle speed issue, knowing that the engine has gobs of power so losing a half horsepower is OK to save the cost of a switching regulator and idle compensator.

That's the kind of system I was thinking about.  I wonder how difficult it would be to modify mine to be like that.

I think I'd be okay with losing half a horsepower if it meant it would cure poor running due to a low battery or worse getting stuck because of a low battery.

[eldar]

Well one option that seems to help is to switch out the mechanical regulator and put in an electronic one. These seem to provide a better range of charging. I am sure the stator can be rewound but it is a delicate operation so you do not mess it up and burn the thing out.

[relative q]

Building an electronic regulator, if you have any soldering experience whatsoever and can read a schematic, is a super cheap and easy thing to do.  The parts cost about $20.

[dustyc]

I've been reading and searching.  I'm going to try what Pinhead has done.

http://www.sohc4.us/forums/index.php?topic=12465.msg119198#msg119198

Any chance you could post pics of the mod on the bike Pinhead?

Thanks for the advice everyone. 

[clarkjh]

There is a electric motor rewinding company here that does stators too.  A lot of GoldWing owners bring their stators to be wound to have higher output for all their lights.  About $100 to $150 Cnd per if I remember right.

James

[coyotecowboy]

About $100 to $150 Cnd

So what's that US, about $20?  kidding, kidding 

There used to be an old feller here in town that would build you an alternator based on what you would be running off of it.  I'll have to look into getting that done.

Thanks for the help guys!!!!

[eldar]

Actually with the crappy mismanagement by Bush and Co. the dollar is worth less than the Canadian dollar now.

[Bodi]

The Canadian dollar is still below the US dollar and has been since about 1963, but they're close to equal now.
An electronic regulator, regardless of marketing claims, can not make more power than the mechanical one. The mechanical type connects the ignition power directly to the field coil through a contact - an electronic regulator can't do any better than that. The magnetic coil in the regulator takes a small amount of power though - an electronic one would potentially make that much more power (insignificant though).
Rewinding the field coil has possibilities, but nobody I know has actually tested it. A coil rewound for more power will necessarily take more power. Will the power output increase be more than the field coil's increased load? Obviously the alternator efficiency drops at low RPM: you might well end up with less net power from the alternator at idle although you're increasing the net power at higher RPM.
Rewinding the output coil for better power production might be possible, I don't know. Again, I've never heard of anyone doing it.

[coyotecowboy]

I've seen aftermarket hi-amp stators for late-model bikes (XR650Rs for dual-sport conversions, that sort of thing) but I don't know why it wouldn't be possible to have one re-wound for an older bike.

[edbikerii]

Is this political crap really necessary in a thread about charging systems?

Actually with the crappy mismanagement by Bush and Co. the dollar is worth less than the Canadian dollar now.

[Gordon]

Is this political crap really necessary in a thread about charging systems?

Actually with the crappy mismanagement by Bush and Co. the dollar is worth less than the Canadian dollar now.

About as necessary as responding to it is, I'd say.

[eurban]

The Canadian dollar is still below the US dollar and has been since about 1963, but they're close to equal now.
An electronic regulator, regardless of marketing claims, can not make more power than the mechanical one. The mechanical type connects the ignition power directly to the field coil through a contact - an electronic regulator can't do any better than that. The magnetic coil in the regulator takes a small amount of power though - an electronic one would potentially make that much more power (insignificant though).
Rewinding the field coil has possibilities, but nobody I know has actually tested it. A coil rewound for more power will necessarily take more power. Will the power output increase be more than the field coil's increased load? Obviously the alternator efficiency drops at low RPM: you might well end up with less net power from the alternator at idle although you're increasing the net power at higher RPM.
Rewinding the output coil for better power production might be possible, I don't know. Again, I've never heard of anyone doing it.

Theory aside the electronic regulator I bought for my 750 from here http://www.oregonmotorcycleparts.com/ allows for well over 13 (in other words is charging the battery) volts at idle RPM.  His claims of 13.5 to 14 volts at idle for this regulator hold true for me. I also have an electronic ignition, 3 ohm coils, and a halogen headlight but this is offset somewhat by and LED tailight and LED turn signals.  I have seen it mentioned in a few places why in theory there is little benefit to a quality electronic regulator but frankly the proof is in the pudding. . . .Overall many issues with our 30+ year old charging systems arise from poor connections in the connectors, fuse box, and switches.  Correct fuses are difficult to find and are sometimes substituted with ones that are too long etc.  Damage to the wires themselves seems also to be common particularly the hidden wiring running underneath the shifter cover (on the 750 anyway).   With a bit of work, there can be alot of "improvement" made to the the SOHCs charging system by putting everything into proper working order.  You can also replace the bulbs for running lights / signals, and tail /brake lights with quality LED units that draw less power.  Heated grips and vest?? Dunno maybe if you installed an on off switch for the headlight and only used the heating during daytime riding??

[edbikerii]

Gordon, please note that I did not respond to it.  If I did, you'd notice some political content in my message.  It is inappropriate to deliberately try to offend innocent readers with political jabs in a thread that has nothing to do with politics.

I'm interested in improving my charging system.  That's why I'm reading, and posting, in this thread, entitled "A better charging system?"

I know of an alternator rebuilding shop that I'm thinking might be able to re-wind a stator, but has anybody confirmed whether there is any room for more windings?  I also wonder whether using a smaller gauge wire would have any positive results?  Perhaps it would be possible to cram wire in more densely if finer wire were used.  Maybe excite more electrons that way?

I would think that, if it were possible and relatively inexpensive, Honda would have increased the windings when headlights became mandatory in the US.  Certainly, the engineers knew that the 550 charging system could barely keep up with the electrical requirements.

About as necessary as responding to it is, I'd say.

[coyotecowboy]

When you are talking charging systems, you need to be more concerned with amps than you do with volts.  Sure, you can up the voltage on your system, and it will make your battery charge faster......but with a battery that is designed to operate in the 12 volt range will it be able to actually do anymore work?  Thats when amperage comes into play.  My shop foreman described it to me as volts being how much volume a system can put out, but amps is more like a pressure reading, if that makes any sense.

And as far as the political stuff goes, Bush isn't the first crappy president we've had, and I think that it's a pretty safe bet that he won't be the last one either.  But ya know what?  We'll get through it!!

[edbikerii]

The voltage regulator will, by definition, stop the alternator from charging when the battery reaches the proper voltage.

When you are talking charging systems, you need to be more concerned with amps than you do with volts.  Sure, you can up the voltage on your system, and it will make your battery charge faster......but with a battery that is designed to operate in the 12 volt range will it be able to actually do anymore work?  Thats when amperage comes into play.  My shop foreman described it to me as volts being how much volume a system can put out, but amps is more like a pressure reading, if that makes any sense.

And as far as the political stuff goes, Bush isn't the first crappy president we've had, and I think that it's a pretty safe bet that he won't be the last one either.  But ya know what?  We'll get through it!!

[eldar]

Actually volts is pressure and amps would be like the total amount.  Winding the alt is touchy in that different wire sizes and the number of winds will affect both volts and amps.   

For example, with a transformer, the first side will be wound a certain way to handle the incoming voltage and amperage.  The second side is would according to the requirement. If you want a lot of volts, you use a finer wire and more turns of wire. This will increase the voltage BUT your amps will fall. Say you start with 120 volts and 10 amps and want to jump to 240 volts, your amps will drop to 5. this is in your basic transformer. 

Main thing is that # of winds and wire gauge will affect both.

The electronic regulators allow the voltage to be kept higher it idle which can then allow the bike to charge when sitting.

Ad for my dollar remark. Well It was not a jab at anyone, other than maybe Bush and maybe we will get lucky and his power will actually be removed and we can stop the useless wire tapping and no-fly lists which keep 7 year olds for getting on planes, crap. But regardless how anyone feels, the fact is that the CND was worth on 68 cents just a few years ago and now the gap is down to 94 cents and the USD is teetering on the edge of being replaced in the global market place by the Euro.  Just checked the exchange rate today on xe.com

[dusterdude]

eldar,as much as i agree with your sentiments,dont think its going to stop when hillary obama gets in office.

[eldar]

Thats why I am hoping for gravel or paul.

[edbikerii]

My experience with a "Rick's Motorcycle Enterprises" electronic voltage regulator was that it did not noticeable improve the low RPM charging.

Certainly, it was not adequate to overcome the drain from the 3 Ohm Dyna coils I installed on my 550 before I knew how wimpy the 550's charging system is.

Also, the device barely lasted a couple of months before it simply failed, leaving me stuck.  I'm pretty sure that premature failure was driven by the excessive draw on the electrical system from those coils, too.

Also, in Rick's defense, that was more than a decade ago, so perhaps his VR technology has improved?

[bistromath]

Keep in mind that if you rewind your alternator to increase output amperage, your bike will be working harder at idle, making it more prone to overheating. You'll probably have to increase idle speed to keep it smooth, too.

Additionally, an electronic regulator will be slightly LESS efficient (I said slightly!) than the OEM Honda mechanical one. Contact resistance in the mechanical reg is lower than the resistance of the switches (FETs or transistors) of the electronic reg. Of course, the electronic one is much more reliable (if well designed) than the relay-driven mechanical. I might be biased, though, I'm an electrical engineer. 

[dustyc]

Keep in mind that if you rewind your alternator to increase output amperage, your bike will be working harder at idle

Why would it work harder?  More magnetic resistance?