Replacing A Motorcycle Battery With A Capacitor
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Your bike is different than mine... It sounds like your ignition circuit doesn't need an external 10-12V through the primary and points like mine does.
I'm *guessing* (anyone more educated on this please fill me in) that you can just treat the secondary wires coming out of the magneto as if it were a secondary on a power transformer.
My bike uses a three-wire three-diode (three phase) rectifier directly out of the stator. It is then smoothed with a big cap, and some models actually have a giant load resistor inline.
It looks a lot like a standard shunted-cap->series-resistor power supply filter, but the regulator in my bike controls the 'exciter' field in the stator only.
I'm sure you can get suitable rectifier/regulator combos online for pretty cheap, or as PRR mentioned (and I've since verified first-hand) the old BSAs and Triumphs used a big zener diode for regulation.
As for providing that initial 12V to the coil primary/points circuit on bikes that do require it, I haven't tried anything yet. I do know that I need that voltage to the primary to get any spark at all.
Preliminary thoughts on this would be to charge a bank of caps with a small battery bank, firing them off when attempting to start akin to a flash circuit on a camera. The tiny bank of Li-Ion batteries that could be used to charge the cap bank would charge once you got it running.
I'm not yet sure of the ramifications of feeding regulated voltage from a stator back into itself to feed its own field coil... I'm sure that the system is designed with the battery acting partially as a capacitor and a load.
I guess I'll actually go back and read this whole post with my new insights.
I'm *guessing* (anyone more educated on this please fill me in) that you can just treat the secondary wires coming out of the magneto as if it were a secondary on a power transformer.
My bike uses a three-wire three-diode (three phase) rectifier directly out of the stator. It is then smoothed with a big cap, and some models actually have a giant load resistor inline.
It looks a lot like a standard shunted-cap->series-resistor power supply filter, but the regulator in my bike controls the 'exciter' field in the stator only.
I'm sure you can get suitable rectifier/regulator combos online for pretty cheap, or as PRR mentioned (and I've since verified first-hand) the old BSAs and Triumphs used a big zener diode for regulation.
As for providing that initial 12V to the coil primary/points circuit on bikes that do require it, I haven't tried anything yet. I do know that I need that voltage to the primary to get any spark at all.
Preliminary thoughts on this would be to charge a bank of caps with a small battery bank, firing them off when attempting to start akin to a flash circuit on a camera. The tiny bank of Li-Ion batteries that could be used to charge the cap bank would charge once you got it running.
I'm not yet sure of the ramifications of feeding regulated voltage from a stator back into itself to feed its own field coil... I'm sure that the system is designed with the battery acting partially as a capacitor and a load.
I guess I'll actually go back and read this whole post with my new insights.
> I want to use a cap on my motorcycle.
Why?
Just take the battery out.
Bulbs will flicker at idle; so what?
The BSA was OK as a daytime dirt-bike. If you are commuting at dusk, I'd think you "need" a battery, Yes, a happy Diesel never fails; but I saw yours in pieces and a fresh put-together leaves the door open for Murphy. There will come a time you need to stand at the side of the road. You don't have BSA's point-trouble, but you might have a resistor-lead hiding in an injector, who knows? You want light for other drivers to aim at, and light to poke your points/filters/whatnot. Yes, carry a flashlight, but why not have a battery too for 15 minutes of grace-light?
Why?
Just take the battery out.
Bulbs will flicker at idle; so what?
The BSA was OK as a daytime dirt-bike. If you are commuting at dusk, I'd think you "need" a battery, Yes, a happy Diesel never fails; but I saw yours in pieces and a fresh put-together leaves the door open for Murphy. There will come a time you need to stand at the side of the road. You don't have BSA's point-trouble, but you might have a resistor-lead hiding in an injector, who knows? You want light for other drivers to aim at, and light to poke your points/filters/whatnot. Yes, carry a flashlight, but why not have a battery too for 15 minutes of grace-light?
sonicmook56
Well-known member
No ignition circuit, or glow plugs at all. The engines compression is high enough that it squeezes the hell out of the fuel until it explodes. The block is small enough not to sink the heat away so it just "goes".
Mine has three wires coming out of the stator as well, I measured them without a load and got 17VAC across one coil and 20VAC across another. Bike was running at a high idle. I originally thought there were diodes inside that gave it some kind of DC? My knowledge on this subject is little.
I like the zener idea. I might do something very simple like this:
THIS
Once I get the lights wired up, I'll figure out the total load. Can someone steer me into the direction of a burley 12v zener that will survive in this application?
sonicmook56
Well-known member
I sketched a basic diagram out on paper. Should be simple.
Ok, good point... I think I'll go with a battery of some sort... Maybe build my own from 1.5v cells as someone else in this thread suggested. I could hide them in one of the side tool boxes and it will look battery-less, while supplying light in an emergency, or a source of power to charge a cell phone.
~B
Ok, good point... I think I'll go with a battery of some sort... Maybe build my own from 1.5v cells as someone else in this thread suggested. I could hide them in one of the side tool boxes and it will look battery-less, while supplying light in an emergency, or a source of power to charge a cell phone.
~B
I have something close to this as a 'three phase' rectifier. I understand it's good to evenly load each winding.
There's some interesting tidbits about the Zener regulator and/or zener as a reference for a regulator here:
http://www.britbike.com/ubb/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=11;t=002848;p=1
There's some interesting tidbits about the Zener regulator and/or zener as a reference for a regulator here:
http://www.britbike.com/ubb/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=11;t=002848;p=1
> burley 12v zener that will survive
Why?
I assume it has provision for a battery. And that this battery, when installed, works. Therefore it IS regulated, at least sorta. If high RPM voltage went over 14.5V the battery would boil (which was an issue on my BSA when the Zener came loose).
Do you have the original electrical diagram?
The Kawa at the top of this thread has a quite strange issue. It does in fact require short-term energy storage to catch dynamo pulses and deliver them as ignition feed. It ASSumes you will ALWAYS have a half-healthy battery. This may be near-valid in Japan and the US, for the people who bought a bike that spiffy/speedy.
Your Diesel doesn't need spark. Moreover, as an India market machine, just as with older tractors and most airplanes, it is unlikely to NEED anything as trouble-prone as a bucket of wet lead/acid. On the farm, or in India, a battery is very nice if you have one. But you must NOT rely on it. A replacement may not be in stock nearby; you may not have cash in hand to buy it. Older tractors CAN hand-start and the magneto WILL spark if simply spun, no battery needed. Quite large piston airplanes, too. India is full of wise men who would build bikes this way. Battery is nice but it can fail (or be removed) and no further harm should happen.
On your plan: normally when you go HI-beam the low-beam is cut-out. And I'm not sure what use an ammeter is if you have no battery to charge.
Motorcycle batteries are CHEAP (in two senses), their ecological impact is small since most Pb gets recycled, I dunno why you don't just stick a battery in.
Why?
I assume it has provision for a battery. And that this battery, when installed, works. Therefore it IS regulated, at least sorta. If high RPM voltage went over 14.5V the battery would boil (which was an issue on my BSA when the Zener came loose).
Do you have the original electrical diagram?
The Kawa at the top of this thread has a quite strange issue. It does in fact require short-term energy storage to catch dynamo pulses and deliver them as ignition feed. It ASSumes you will ALWAYS have a half-healthy battery. This may be near-valid in Japan and the US, for the people who bought a bike that spiffy/speedy.
Your Diesel doesn't need spark. Moreover, as an India market machine, just as with older tractors and most airplanes, it is unlikely to NEED anything as trouble-prone as a bucket of wet lead/acid. On the farm, or in India, a battery is very nice if you have one. But you must NOT rely on it. A replacement may not be in stock nearby; you may not have cash in hand to buy it. Older tractors CAN hand-start and the magneto WILL spark if simply spun, no battery needed. Quite large piston airplanes, too. India is full of wise men who would build bikes this way. Battery is nice but it can fail (or be removed) and no further harm should happen.
On your plan: normally when you go HI-beam the low-beam is cut-out. And I'm not sure what use an ammeter is if you have no battery to charge.
Motorcycle batteries are CHEAP (in two senses), their ecological impact is small since most Pb gets recycled, I dunno why you don't just stick a battery in.
OH!!! Horn probably WON'T work from the dynamo. It has high peak current for very short time. It must have a battery to suck. And since horn is both an Inspection item and common sense on a vulnerable bike, you want a battery.
OIC. Your basket case did not have any of the electrical tidbits?
You should have a regulator and a rectifier. It is not clear yet if you have 2-phase, 3-phase, floating or grounded common, regulator on field or just clamping the output. In fact your "AC" could be pulsating DC.... different meters read this differently.
> I'll figure out the total load
For US-level lighting (which may not be Indian standard): 25W/35W to headlight, 12W Stop, another 20W for minor lights. 5A-6A total. Might be a 8A-10A dynamo so your battery gets juiced at night.
Of much more interest: what is the maximum output current of the dynamo and can it be overloaded without harm?
Or is there a Field Coil lead you have not mentioned/found? And a Regulator in a basket you did not get? One of those "stator" leads could be Field: no-load, it would output something when spun, even though it should be a power input.
The BSA was apparently designed safe with a 15V clamp. I figure this meant about 75W of waste heat in the windings at max RPM. But 75W is 0.1HP, max RPM was 15HP to the clutch so about 15HP of heat coming off the engine in all directions. Another 0.1HP of heat in a corner would be insignificant waste.
I think you need more info about how THIS cat was skinned, before you look at the too-many different ways a bike may be wired.
OIC. Your basket case did not have any of the electrical tidbits?
You should have a regulator and a rectifier. It is not clear yet if you have 2-phase, 3-phase, floating or grounded common, regulator on field or just clamping the output. In fact your "AC" could be pulsating DC.... different meters read this differently.
> I'll figure out the total load
For US-level lighting (which may not be Indian standard): 25W/35W to headlight, 12W Stop, another 20W for minor lights. 5A-6A total. Might be a 8A-10A dynamo so your battery gets juiced at night.
Of much more interest: what is the maximum output current of the dynamo and can it be overloaded without harm?
Or is there a Field Coil lead you have not mentioned/found? And a Regulator in a basket you did not get? One of those "stator" leads could be Field: no-load, it would output something when spun, even though it should be a power input.
The BSA was apparently designed safe with a 15V clamp. I figure this meant about 75W of waste heat in the windings at max RPM. But 75W is 0.1HP, max RPM was 15HP to the clutch so about 15HP of heat coming off the engine in all directions. Another 0.1HP of heat in a corner would be insignificant waste.
I think you need more info about how THIS cat was skinned, before you look at the too-many different ways a bike may be wired.
aomahana
Well-known member
Hi,
I have a 1988 Honda 250 XLR BAJA. This bike is designed to run without a battery. There is a capacitor mounted near the headlight assembly (not too large). I have been unable to find a service manual for this model though, so I can't tell you any details about the circuit. But it does show it can be done.
I have a 1988 Honda 250 XLR BAJA. This bike is designed to run without a battery. There is a capacitor mounted near the headlight assembly (not too large). I have been unable to find a service manual for this model though, so I can't tell you any details about the circuit. But it does show it can be done.
sonicmook56
Well-known member
PRR, thank you. I was planing to wire the machine up "redneck" style. I really need to study up and know exactly what's going on.
I need to find out exactly what the output of the stator is. Probably do that this weekend when I pull the clutch apart.
I do have the original wiring, but it's in awful condition. whoever owned the bike before me made connections simply by twisting wires together and covered with packing tape.
This box is wired into the headlamp assembly of the second Enfield I have. The switch is labeled "normal" and "music". What is does is a mystery. Maybe it's a "la cucaracha" horn? :grin:
Ammeter is wired in because I can't take it off the bike without having a big hole on the "dash"
As for the rest of the parts on the wiring harness, there was a rectifier.
A flasher unit with what looks like an audio transducer attached to it.
and this thing, that might be the regulator?
The only thing I'm keeping are the switches for signals, exc...
let me see if I can find a wiring diagram for it... Probably won't be diesel specific, but for the gasoline counterpart. Might help determine what the wires on the output do.
I need to find out exactly what the output of the stator is. Probably do that this weekend when I pull the clutch apart.
I do have the original wiring, but it's in awful condition. whoever owned the bike before me made connections simply by twisting wires together and covered with packing tape.
As for the rest of the parts on the wiring harness, there was a rectifier.
A flasher unit with what looks like an audio transducer attached to it.
and this thing, that might be the regulator?
The only thing I'm keeping are the switches for signals, exc...
let me see if I can find a wiring diagram for it... Probably won't be diesel specific, but for the gasoline counterpart. Might help determine what the wires on the output do.
> and this thing, that might be the regulator?
It looks like it would taste like a regulator; size, terminals. Even says "12V", as if there were a 6V model around from earlier years. But "H B S(?)" is not jogging my chimes.
> The switch is labeled "normal" and "music".
That's astonishingly modern. More transistors than my Willys, BSA, Falcons and Cougar put together. I'm guessing it is a horn relay and a cultural thing. That you have a polite too-tee-toot! horn and a HOOAUGNNKKK! horn. One for in-village to urge children and chickens along, or "wave" friends; the other for the Big City to intimidate trucks.
> what looks like an audio transducer
Looks like a high-pitch buzzer. Back-up warning for a truck. Might be related to turn-signals?
> The only thing I'm keeping are the switches
Keep everything. It may be more important than it looks. I agree that most of that junk should not go back on the bike without massive restoration. (And if it is Lucas, a soak in warm beer. If that doesn't heal it, shim some Honda switches onto the machine.)
What original colors match? The dynamo and rectifier --may-- have the same (pre-patching) color codes.
> see if I can find a wiring diagram for it... Probably won't be diesel specific
Probably exactly the same except the part you are missing (sparks).
Is this the same machine, below the piston, as some spark machine?
Ignore the mix-n-match bits. There is a core mechanical and various parts used to make a specific model. My BSA was a post-war go-to-work machine, but my model was gussied-up with high tailpipe, knobby tires, and no slow-idle. It was an English Trials wannabe, but BSA was selling it to US kids for the kind of stunts now called Enduro, Motocross, and Freestyle, but we called it messing-around. A commercial bike might get different brakes, springs, seat, racks, handlebars, and still be the same core machinery.
A Diesel is usually built on a very different foundation than a sparker. As GM proved again by Dieseling a perfectly good 350 sparker. However for a low-production modest performance one-lunger, it makes some sense to start with a an existing in-production large-sparker's crank, case, oiler, cam-works, gearbox, etc. Perhaps the points-shaft can drive the injection pump. Max RPM is lower due to lean slow combustion. Nett result is much less HP, but a hot 250 sparker is a ripping machine in lands where 750cc and 427CID machines are unknown.
So yeah: if there is a sparker one size up with same-looking crankcase, I bet the electrical is the same except the stuff that is different. And being a sparkless engine, the Diesel is just missing an obvious sub-circuit.
Hmmm. The Enfield Bullet never changed, even when built different sizes... but Enfield Taurus seems to cover DOZENS of oilburners, factory and DIY.
A Diesel is utterly waterproof, which may be super valuable in India's monsoons.
http://www.epfguzzi.com/4bullets/models/nothere.html
"Saree guards on both sides."
It looks like it would taste like a regulator; size, terminals. Even says "12V", as if there were a 6V model around from earlier years. But "H B S(?)" is not jogging my chimes.
> The switch is labeled "normal" and "music".
That's astonishingly modern. More transistors than my Willys, BSA, Falcons and Cougar put together. I'm guessing it is a horn relay and a cultural thing. That you have a polite too-tee-toot! horn and a HOOAUGNNKKK! horn. One for in-village to urge children and chickens along, or "wave" friends; the other for the Big City to intimidate trucks.
> what looks like an audio transducer
Looks like a high-pitch buzzer. Back-up warning for a truck. Might be related to turn-signals?
> The only thing I'm keeping are the switches
Keep everything. It may be more important than it looks. I agree that most of that junk should not go back on the bike without massive restoration. (And if it is Lucas, a soak in warm beer. If that doesn't heal it, shim some Honda switches onto the machine.)
What original colors match? The dynamo and rectifier --may-- have the same (pre-patching) color codes.
> see if I can find a wiring diagram for it... Probably won't be diesel specific
Probably exactly the same except the part you are missing (sparks).
Is this the same machine, below the piston, as some spark machine?
Ignore the mix-n-match bits. There is a core mechanical and various parts used to make a specific model. My BSA was a post-war go-to-work machine, but my model was gussied-up with high tailpipe, knobby tires, and no slow-idle. It was an English Trials wannabe, but BSA was selling it to US kids for the kind of stunts now called Enduro, Motocross, and Freestyle, but we called it messing-around. A commercial bike might get different brakes, springs, seat, racks, handlebars, and still be the same core machinery.
A Diesel is usually built on a very different foundation than a sparker. As GM proved again by Dieseling a perfectly good 350 sparker. However for a low-production modest performance one-lunger, it makes some sense to start with a an existing in-production large-sparker's crank, case, oiler, cam-works, gearbox, etc. Perhaps the points-shaft can drive the injection pump. Max RPM is lower due to lean slow combustion. Nett result is much less HP, but a hot 250 sparker is a ripping machine in lands where 750cc and 427CID machines are unknown.
So yeah: if there is a sparker one size up with same-looking crankcase, I bet the electrical is the same except the stuff that is different. And being a sparkless engine, the Diesel is just missing an obvious sub-circuit.
Hmmm. The Enfield Bullet never changed, even when built different sizes... but Enfield Taurus seems to cover DOZENS of oilburners, factory and DIY.
A Diesel is utterly waterproof, which may be super valuable in India's monsoons.
http://www.epfguzzi.com/4bullets/models/nothere.html
"Saree guards on both sides."
