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Discussion Starter · #1 ·
Hi all,
Thinking about doing away with the battery on my T140 and wondering what my options are. Im running points and only the head and brake lights. I've seen people mention capacitators, what do they do? Would the stock alternator produce enough output to run the bike? Will I need a magneto? Who is Joe Hunt? haha
Thanks in advance for your help!
 

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Sorry Triumphjoe,what is a Douver,I have never heard of this before?
+1 here. For the zillionth time this matter is asked again. Search here or Britbike.com for answers aplenty. RR
 

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..Douver,ain't that down in Kent?Seriously,why not stick with a battery?Cheap option really & the gel types are low maintenance.Magnetos?expensive... nyway..good luck..Cheers!
 

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It will run on the alternator sometimes

Hi all,
Thinking about doing away with the battery on my T140 and wondering what my options are. Im running points and only the head and brake lights. I've seen people mention capacitators, what do they do? Would the stock alternator produce enough output to run the bike? Will I need a magneto? Who is Joe Hunt? haha
Thanks in advance for your help!
The most common application for going batteryless is the racing crowd.
They have no need to run a headlight or a horn and start their engines with an external unit. A capacitor stores a charge that will get you enough spark to start the engine until the alternator takes over at 2100 rpm. You may have a problem in stop and go traffic keeping that rpm up. I used to carry a Rayovac 6-volt lantern battery with 2 alligator clips in my pocket for when that happened. Some guys love their magnetos hanging off the side of their motors and don't mind having any spark advance/retard to help start the engine. I assume you want a cleaner look. What is your expected use for the bike? Would limited reliability be OK? Would a very small battery fit with your plan? Bob
 

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Going battery less would be an interesting project and I have read about some here and elsewhere that have done it.

On T100's they go all AC so low rpm doesn't matter as much, if you can stand dim lights. But with AC you really need some form of clipper diode that prevents you blowing your lights at high RPM. I should add that T100's use a special 5-wire alternator.

In theory it should work with a three phase alternator but time and again here you read about miss-firing at low rpm with low battery voltage. Now if you take your battery out you will have no battery volts so miss-firing at low rpm looks inevitable. However, without a low voltage battery in circuit taking current to charge it you will have more voltage available for your coils (and lights) so miss-firing shouldn't be as bad as expected.

A capacitor, to your alternator/regrec, looks like a small battery so should help with the miss-firing but, if you are going to fit a capacitor why not fit a battery?
 

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Hey!
I have a 78 t140 and am doing the same thing. I actually just wired it upand got my first spark today.
So... I created my own custom wiring diagram based on others I have seen here, and elsewhere. I went with all Sparx gear. Pretty reasonable too. I got the capacitor to replace the battery, and the electronic ignition with new inline 6 volt coils (which I highly recommend if you are going batteryless). This will also eliminate your zener and condensors, further simplifying the harness.
In the wiring, I put a on/off switch for the headlight. Turning it off during starting will prevent taxing the ignition of juice. The beauty of this system is that you can still add a battery to support the accessories if you decide it's needed. It all turned out pretty simple, but I have yet to wire up the headlight and tail light. So, Im still not sure how they will run.
I'll try to scan the wiring diagram and uploaded soon.
 

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Discussion Starter · #11 ·
Thanks guys!
Basically Im just trying to simplify the bike, I thought if battery-less was simple it could be an option. Maybe the best idea would be a smaller battery and maybe a dry cell so it can be laid flat. I want to hide it under the seat somewhere. Does anyone have any suggestions? What specs do I have to look for in a battery (12 volts I know but what Ohms etc?).
Douver (Doover): Something unspecified whose name is either forgotten or not known. Australian slang.
Thanks in advance!
 

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Maybe the best idea would be a smaller battery and maybe a dry cell so it can be laid flat. I want to hide it under the seat somewhere.
That makes more sense.

This is all you need from Supercheap or Repco. RR

[/IMG]
 

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..my heads starting to spin... "hide it under the seat....?" is this a wind-up or what?
If your going to all this trouble to hide a battery in the battery tray...

I'm going to have a lie down in a quite room ... Back tomorrow... Nurse?Nurse?
.........?"The screens,quick!"
 

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Reliable electronics

Thanks guys!
Basically Im just trying to simplify the bike, I thought if battery-less was simple it could be an option. Maybe the best idea would be a smaller battery and maybe a dry cell so it can be laid flat. I want to hide it under the seat somewhere. Does anyone have any suggestions? What specs do I have to look for in a battery (12 volts I know but what Ohms etc?).
Douver (Doover): Something unspecified whose name is either forgotten or not known. Australian slang.
Thanks in advance!
For simplicity, I would recommend an AGM maintenance free battery. This would give you good reliability. The most important spec on the battery is the dimensions. The one in RR's picture is a 7AH (amp hour) and is adequate for a kick-start bike. Another advantage to an AGM battery is they can be shipped complete as they do not use acid. I would simplify the voltage regulator, substituting a solid-state one for the rectifier and Zener diode. An AGM battery, electronic regulator, and a modern fuse and your system is complete. Bob
 

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triumphjoe,

The new batteries are clean and low maintenance so it would probably be best to use one as some others have said. I had a 500 Triumph TR5T in the 70's. I rode it for years without a battery. It had a capacitor and was stock but I removed the lights. It ran great and never had a problem and I rode it thousands of hard miles in the desert in Arizona.

I think it's possible to run without one but a battery is probably the most realistic way to go.

Joe
 

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I was going to go battery-less on my Norton. It is fired by a Hunt mag and I used a Boyer Powerbox. First thing is, the lights will be very dim and flicker at stops. The front was not an issue but the brake light will appear to come on, and then as the revs drop off, go out. I had a few close calls (rear ended) as the people behind would think I wasn't slowing down. Second, I did not have enough power to honk the horn despite my charging system putting out, according to my digital multimeter, the correct output. There are capacitors to use in the system that will allow for a a spike in power, but I never did spend the money one just to try it out. Instead a bought a small 12v 5a battery that is apparently used in something completely different. Approx 4' wide, 5" long and 5.5" high. I got it at a battery shop but electircal supply houses have them too.

Edit, yeah about the same thing that RetroRod posted....duh read the whole thread I guess before posting?
 

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It looks like some people don't have enough faith in a Lucas 120W single phase alternator.Running without a battery is usually easier with points,they'll start with 6V.You can even start with the headlight on,though it's not so easy.

If the alternator works you just need an electrolytic capacitor,about 4000 -5000 microFarad.The Lucas spring-mounted capacitor is OK.I've used other capacitors wrapped in foam rubber and zip-tied in place.They are polarity-sensitive;instantly ruined if connected reverse-polarity.I reckon its a great thing to have,so you're not totally reliant on the state of your battery.If you use a battery,you can fit a switch and only use the capacitor in an emergency.It will usually start easier if you disconnect a stone-flat battery (pull the fuse).
If the alternator output was at a maximum whenever the points opened,you wouldn't need a capacitor.You get 12 pulses,30 crankshaft degrees apart.You also get 24 degrees ignition advance.Some bikes will start without a battery or capacitor,but won't rev up because the alternator goes out of phase as the ignition advances.
Some bikes are phased better and will start with a 15-year-old stone flat battery connected,and still run perfectly.They won't run so well with no battery (or capacitor) in the system.

With a capacitor and no battery,you'll get full voltage at 2000 rpm with the headlight on.The zener or rec/reg will be draining off excess power.There's more load on the zener,because none of the excess power is used to charge a battery.At high rpm (7000 or so),there's more chance you'll burn out a headlight from excess voltage.If you're sensible,it's not a big problem.
Don't expect to idle much lower than 1000 rpm with the headlight on.Chances are that the engine will stall when you open the throttle.Don't expect much response from the horn.At low rpm it could stop the engine.

You can get by without the battery.The zener works harder,and runs hotter trying to keep the voltage down.2 matched zeners would be a good idea.Electrolytic capacitors don't last forever.When they get old (about 20 years),they can drain a battery if they're permanently connected.It may still start and run on the capacitor alone,but it's "leaky".
 

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<Some bikes are phased better>
Why do you think that is Mr.Pete? All the rotors I have the keyway aligns to the centre of a magnet so I am puzzled as to what is going on. Does the keyway position vary on the crankshaft perhaps?
 
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