[SS-Traveller]

Originally Posted by GTO

Therefore, the only solution in this case are jumper cables? I keep a set handy and they've been used multiple times in the last year or two.

Generally, yes.

In case one has a completely dead battery where the horn won't sound or the headlights can't glow, and for a manual transmission car that supports being push-started, even borrowing a 12v motorcycle battery and connecting it up with cables will allow the engine to fire up with a push start. Obviously, the motorcycle battery is incapable of cranking the starter motor, but it will supply enough current at the right voltage to let the electronics work for a short while (till the engine fires).

[Urban_Nomad]

Originally Posted by Urban_Nomad

Spot on! My 2004 T-Bird has been running without a battery for over 3 months now. Still "Half kick start"

Originally Posted by Jeroen

Your Thunderbird not wanting to start with a bad battery has most likely nothing to do with CDI

Originally Posted by tharian

The 2009 Thunderbird is a carb one with a TCI system for ignition.
It does not have an ECU.

Enfield sold few models with CDI units for a span of 4 years in early 2000. These run and start without a battery/dead battery.

Question - What are the ill effects of running a motorcycle without a battery? Obviously, the battery wont charge and go dead but could there be issues that the motorcycle would face because it has not been running on a battery?

[tharian]

Originally Posted by Urban_Nomad

Question - What are the ill effects of running a motorcycle without a battery? Obviously, the battery wont charge and go dead but could there be issues that the motorcycle would face because it has not been running on a battery?

As far as I know, none.
But I would hate to ride without a charged battery since none of the important lights work in their full capacity, except for the headlamp.

[motorpsycho]

You can start your bike on a dead or no battery. When we use a kick the kick gear only activates the magneto for a brief period of time. The reason is the gear is a partial spiral.



When you push start with a half clutch, the tires rotates the magneto till you come to a stand still or the bike fire up.

*Please correct me if I am wrong, I also may have got confused with Magento and the Stator.

[phamilyman]

Originally Posted by Urban_Nomad

Question - What are the ill effects of running a motorcycle without a battery? Obviously, the battery wont charge and go dead but could there be issues that the motorcycle would face because it has not been running on a battery?

None. My pulsar 180 worked for 2.5 years with a near-dead battery. With my regular travels, the bike was often used after 2-3 months. No one else bothered about it so there was no point installing a new battery either.

The only bug was that the horn didn't work. Let's just say after a few initial shocks, I evolved my riding style and became far more defensive.

Like the quote says - what doesn't kill you makes you stronger. I highly recommend everyone to go horn-less for a few weeks in a year as a re-skilling exercise!!

[navin_v8]

Interesting topic and some interesting replies. A battery is not the sole thing responsible for starting a motorcycle it also depends on the ignition system. Coming to the near dead or fully dead battery on motorcycles with CB point, CDI and TCI ignition. I wont get into a very technical discussion but very basic explanation. Let us take them one by one:

CB point: It is very difficult to start as motorcycle with a dead battery having a CB point ignition. The CB point ignition is extinct in modern motorcycles and is only used by old motorcycles read RE Standard Bullet CI, Yamaha RD350, Jawa Yezdi, etc. (the latter two also came with CDI ignition at later stages but for now let's stick to CB point ignition). The CB points require the battery to be in good condition to kick start the bike else one can resort to push starting the motorcycle which will eventually start the motorcycle. If the battery is low on charge then it will be recharged by the alternator, if the battery has no charging ability due to age and shelf life then it will keep giving troubles until replaced with a new battery. The battery can also be jump started using jumper cables and a donor battery provided one knows the correct polarity to avoid short circuit. Today we also have palm sized Lithium battery jump starters(read expensive) along with traditional jump starter kits which boosts the amps to start the motorcycle with a near dead battery.

CDI ignition: Due to its ability to start a motorcycle without a battery most of the dirt bikes uses this ignition. A dirt bike has no lights or horn whatsoever so it does not require a battery to power these electricals. Most motorcycles from the 1970's and 80's used a CDI ignition which was fairly reliable and trouble free compared to CB points. Same reason why we see many Yamaha RD350 owners converting their bikes from CB point to CDI ignition. We have two motorcycles in my family which uses CDI ignition one is my own 2004 RE Tbird AVL 350 and other is the first gen Hero Honda CBZ. Both these motorcycles start with a near dead or without a battery, even during cold winter days. I believe the alternators used in CDI ignition motorcycles are heavy duty compared to their CB point and TCI counterparts. To give an example my brother in law who has the first generation Hero Honda CBZ with CDI keeps the bike standing for 3-4 months as he is merchant navy. After coming back he kicks the kick lever about 5-6 times and the CBZ roars to life. He has been doing this since the bought the bike. When I bought my used 2004 Tbird AVL 350 CDI the previous owner had fitted a puny UPS battery for namesake. I was going to throw it out but decided to carry on with it. I haven't replaced the battery as yet and the bike still runs albeit the horns, indicators and lights feel weak.

Quoting from Wikipedia: "A CDI system has a short charging time, a fast voltage rise (between 3 ~ 10 kV/μs) compared to typical inductive systems (300 ~ 500 V/μs) and a short spark duration limited to about 50-80 µs. The fast voltage rise makes CDI systems insensitive to shunt resistance. The insensitivity to shunt resistance and the ability to fire multiple sparks can provide improved cold starting ability."

"CDI modules are of two types AC-CDI and DC-CDI: The AC-CDI module obtains its electricity source solely from the alternating current produced by the alternator. The AC-CDI system is the most basic CDI system which is widely used in small engines. The DC-CDI module is powered by the battery, and therefore an additional DC/AC inverter circuit is included in the CDI module to raise the 12 V DC to 400-600 V DC, making the CDI module slightly larger. However, vehicles that use DC-CDI systems have more precise ignition timing and the engine can be started more easily when cold."

TCI ignition: Again this behaves somewhat like a CB point while the battery is near dead or dead while starting the bike, however there is where the story ends as TCI is miles ahead of CB point both in terms of efficiency and ease of maintenance. One can push start the bike provided it uses a carburettor and not an EFi. A TCI takes a lot of power from the charging system to power the spark plug in order to provide a longer and more powerful spark for combustion and fuel efficiency. A TCI ignition motorcycle with a near dead or dead battery can be jump started using a donor battery with jumper cables or the palm sized lithium jump starter booster.

All these systems come with their own advantages and disadvantages, I have multiple motorcycles and face this issue of battery drain. The solution I have come up with is using a motorcycle battery charger which I use to charge the battery when it becomes weak. I can't use float charging as I don't have a dedicated garage wherein I can keep the charger plugged in to the battery to float charge. Another useful accessory I plan to buy is a pocket sized lithium battery jump starter which will help me jump start a discharged battery within seconds.

Lastly I always take the keys of my CDI Tbird AVL 350 as a backup whenever I have to go out. If my CB point Bullets and TCI Tbird500 don't start at the nth hour, I key in to my CDI Tbird AVL which starts without a fuss come winter or rain.

[alpha1]

Originally Posted by navin_v8

... as TCI is miles ahead of CB point both in terms of efficiency and ease of maintenance. One can push start the bike provided it uses a carburettor and not an EFi. A TCI takes a lot of power from the charging system to power the spark plug in order to provide a longer and more powerful spark for combustion and fuel efficiency...

Thanks a lot.
I remember about 10 years ago when TBird started appearing with TCI ignition and I used to wonder why my TBird (2003) is not so fussy about the battery.

So what is the verdict on CDI vs TCI?
Does TCI present so much improvement in performance that CDI's ruggedness advantage stand no ground in front of it?

[navin_v8]

Originally Posted by alpha1

So what is the verdict on CDI vs TCI?
Does TCI present so much improvement in performance that CDI's ruggedness advantage stand no ground in front of it?

Mate as I said before each has their own set of advantages and disadvantages and hence are chosen by manufacturers. TCI is used for obvious reasons over a CDI due to emission norms and fuel efficiency. One can see that almost all the bikes today use TCI while some continue to use CDI. The very basic fundamental of how a CDI and TCI works are totally opposite and chosen by the manufacturers how it suits them. To give you an example as told to me by my mechanic(specific to RE motorcycles) a CDI uses a heavy duty alternator(compare the your CDI AVL Tbird clutch case with TCI AVL Tbird and you will see the difference) in addition a Tbird AVL CDI uses some more mechanical parts(not the CDI unit per se) as compared to a TCI AVL Tbird. I believe a TCI uses lesser parts than a CDI and is hence cost effective to the manufacturer with the added benefit of fuel efficiency due to complete combustion that complies with the emission norms.

Now with modern batteries coming with VRLA and AGM technology which can hold the battery charge for a long time the CDI's advantage of starting a motorcycle without battery is somewhat taken care of.

[naveenroy]

Originally Posted by navin_v8

All these systems come with their own advantages and disadvantages, I have multiple motorcycles and face this issue of battery drain. The solution I have come up with is using a motorcycle battery charger which I use to charge the battery when it becomes weak. I can't use float charging as I don't have a dedicated garage wherein I can keep the charger plugged in to the battery to float charge. Another useful accessory I plan to buy is a pocket sized lithium battery jump starter which will help me jump start a discharged battery within seconds.

What charger do you use? And yes, I have a battery technician who uses the battery jump starter - but those are kinda pricey.

[navin_v8]

Originally Posted by naveenroy

What charger do you use? And yes, I have a battery technician who uses the battery jump starter - but those are kinda pricey.

Mate there are a plethora of options to choose from right from palm sized smart chargers to the traditional bulky chargers. I have the modern smart charger that automatically detects the battery condition and starts charging it using a step by step charging method and is also very safe to use as it is protected against reverse polarity. The unit I am using is called Noco Genius G1100 smart charger which charges all batteries right from 2 amps to 40 amps. This amperage range covers all my motorcycles and car. The unit itself is not very affordable as it retails at 5-6K. We also have other popular brands like Black and Decker and Bosch making these kind of smart chargers within the same price range. I am also planning to buy a pocket size lithium battery jump starter to jump start the batteries(car and motorcycles) whenever they go down. Then again these smart jump starters cost upwards of 6 to 8K.

Frankly this kind of price is not justified for one who has a single motorcycle or car as the friendly neighbourhood battery shop will be way more cheaper and hassle free. But for DIY'ers like me who have 5 motorcycles and a car the price is justified as I don't have to make multiple trips to the battery shop.

[simplynitin]

Thank you everyone for the helpful information. Continuing on my quest to fully understand the ignition system, I have poured over more material related to this. Let me try and explain my current understanding in a step by step manner:

CDI:
When you kick-start, it rotates the engine which in turn rotates the stator. The stator provides the ac current to charge the Capacitor.
For trigger, there is a pickup coil. A flywheel with a fixed magnet rotates close to the pickup coil and when the magnet crosses the pickup coil, it generates a low voltage pulse which works as a firing signal
When the firing signal is received by the CDI unit, it gives the input to discharge the capacitor. This generates current through the primary coil in the ignition coil unit. This current is amplified by the secondary coil and sent directly to spark plug. The volts sent to spark plug is usually in a range of 600 to 2000 volts providing enough juice to create the spark.
The stator also provides power to the electrical components, like horn, headlight, blinkers and rectifier/regulator. The rectifier converts the ac into dc and feeds the battery for recharging.

Here are a couple of youtube links which helped me:

https://www.youtube.com/watch?v=0yK3Opq_i0M

https://www.youtube.com/watch?v=UEXJWHlA3CE

This summarizes the functioning of a CDI system. The battery has no role to play in this system and hence a bike using CDI can be kick-started with a dead or even no battery with ease.

TCI:
Whatever little information I can find on TCI says that it has a transistor which controls the ignition timings. Big surprise that Transistorized Control Ignition has a transistor.
The following link also indicates that the primary coil is connected directly to the battery. But that will make push-starting the bike impossible (Something that I have done successfully in the past)
http://www.jetav8r.com/Vision/IgnitionFaq.pdf

Questions:
Seeking help from the electrical gurus to get info on the following queries:

CDI :
1) Is stator and alternator the same thing? If not, where does the alternator fits in the scenario above?

TCI :
Does TCI has a capacitor like CDI which feeds the primary ignition coil?
If the timing of ignition is controlled by transistors, what is the role of pickup coil? Does this system even has a pickup coil?
What is the role of stator in this system?
How is TCI different from CDI (apart from having a transistor)

As you can see, the understanding of TCI system is less than basic. Any help in explaining the TCI system step by step would be greatly welcome.

[ArizonaJim]

simplynitin
Perhaps this will answer your question about the alternator:

Your description above is almost correct except the rotating part is the armature.

The alternator which produces the electricity consists of a stationary stator and a rotating armature.

The rotating armature produces the rotating magnetic field to generate the electricity in the non-moving stator coils.

In the automotive world, the armature has electrical coils on it to produce the magnetic field needed to excite the stator and produce the power.
The auto's electrical system supplies the needed power in varying amounts to the armatures coils to control the stator's output.
This allows an automotive alternator to produce large amounts of power even when the engine is running at very low speeds while not supplying too much power when the engine is running at higher speeds.

On most motorcycles, rather than having electrical coils, the armature has permanent magnets embedded in it to excite the stator when the armature is rotating.**
This allows the motorcycle alternator to be light weight and simple.
The following discussion is directed at the motorcycles type of alternator.

The strength of these permanent magnets is set to produce enough power at moderate to high engine speeds to power all of the electrical needs of the motorcycle. This includes powering the engines ignition coil and circuits to control it, the headlight and recharging the battery.
In the case of fuel injected motorcycles it also includes powering the electric fuel pump and computer.

With the engine shut off, no power is being produced.
At very low speeds such as kick starting, a very small amount of electrical power is produced.
This may or may not be sufficient to produce a spark at the spark plug. (Having the headlight in an "on" condition saps the power needed by the coil which can prevent the needed spark to start the engine).

At very low engine speeds such as when the engine is idling, the power output of the alternator is usually just enough to power the ignition coil and the headlight.
Usually at an idle speed, the battery is being discharged by providing the needed power to light the headlight.

Hopefully this helps you understand what is going on.

** Technically, the design that uses electrical coils on the rotating armature is a alternator.
The design that uses permanent magnets on the armature is a magneto but for simplicity (and perhaps to sound more modern) we call it a alternator anyway.

[simplynitin]

Originally Posted by ArizonaJim

simplynitin
Perhaps this will answer your question about the alternator:

Your description above is almost correct except the rotating part is the armature.

Thank you for clarification. With the above, I believe the CDI system should be easy to understand for anyone who goes through this thread.

Originally Posted by navin_v8

TCI ignition: Again this behaves somewhat like a CB point while the battery is near dead or dead while starting the bike, however there is where the story ends as TCI is miles ahead of CB point both in terms of efficiency and ease of maintenance.

I believe the major difference between CB point and TCI (or even CDI for that matter) is that TCI doesn't utilizes any physical contact points. This eliminates the wear and tear of the contact points.
Still need to understand how TCI works in detail though.

Can you throw some light on the questions I posted above please?

Originally Posted by simplynitin

TCI :
Does TCI has a capacitor like CDI which feeds the primary ignition coil?
If the timing of ignition is controlled by transistors, what is the role of pickup coil? Does this system even has a pickup coil?
What is the role of stator in this system?
How is TCI different from CDI (apart from having a transistor)

As you can see, the understanding of TCI system is less than basic. Any help in explaining the TCI system step by step would be greatly welcome.

[navin_v8]

Originally Posted by simplynitin

I believe the major difference between CB point and TCI (or even CDI for that matter) is that TCI doesn't utilizes any physical contact points. This eliminates the wear and tear of the contact points.

Yes indeed the wear and tear in a TCI and CDI ignition system is next to nil, but that doesn't mean it doesn't undergo wear and tear. It does undergo wear and tear due to heat related thermodynamics.

Still need to understand how TCI works in detail though.

Can you throw some light on the questions I posted above please?

I am no electrical engineer but I have found some useful resources that details the working of a TCI system along with a US patent documentation on TCI. I am not posting all of them here as it would be a mighty big read and also it has some technical diagrams. You can refer to them on these links:

http://www.google.co.in/patents/US3765391

http://constructionmanuals.tpub.com/...s/14050_96.htm

http://www.sl113.org/wiki/Electrical/TransistorIgnition

I hope these links clear your questions.

[bhogalrajnish]

Hi Friends,

The battery on my Karizma has gone week. I know one can replace the battery with a capacitor or at least add a capacitor so that overall voltage is good. has anyone done a DYI around adding a capacitor to a motorcycle ?

I don't care about the electric start can do with he kick starter itself.

Regards
Rajnish