Why Do We Need A Battery

[Guest]

I've been wondering, Why do our bikes NEED batteries. On the bikes without kickstarters you would need it to start the bike, but with a kickstarter wouldnt it be possible to modify the bike to not require the battery and to run reliably purely on its own recycled energy?

Seems to me that the battery is more trouble then its worth...

[tkent02]

I've been wondering, Why do our bikes NEED batteries. On the bikes without kickstarters you would need it to start the bike, but with a kickstarter wouldnt it be possible to modify the bike to not require the battery and to run reliably purely on its own recycled energy?

Seems to me that the battery is more trouble then its worth...

Some guys use tiny batteries and plan on kickstarting, I think you could remove it completely but you would need a big capacitor in place of the battery to keep from frying the regulator or something in the charging system. Better do a little research on that.

[Adler]

Am I mistaken in thinking that the only purpose of the battery is to start the bike and to smooth the current? If so, then isn't it a huge waste of space for most people on a bike with a kickstarter?

I mean, I can kickstart my bike with my hand! And its not even hard!

I'm shocked more people don't do this, Ill research it in the morning but I wish someone with more electrical background would pursue this.

[posplayr]

Am I mistaken in thinking that the only purpose of the battery is to start the bike and to smooth the current? If so, then isn't it a huge waste of space for most people on a bike with a kickstarter?

I mean, I can kickstart my bike with my hand! And its not even hard!

I'm shocked more people don't do this, Ill research it in the morning but I wish someone with more electrical background would pursue this.

Like Kent said the R/R's job will be pretty tough without battery. When the R/R regulates it disconnects the stator from the electrical system so if something is not there to provide the current the bike will cut out. A small battery is the best solution.

[Steve]

You would also have to ensure that your charging system is putting out enough to run the bike when it's idling.

When the charging system is not putting out enough, the battery supplies what's needed. No battery? No run, in that case.

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[Graham]

It could be done but why would you want to? Stator and regulator would hve to be changed with something custom made. It would cost more to change then it is worth.

[tkent02]

You guys think a little 12 volt NiCad pack would work? Something like the electric RC cars and airplanes use?

[Adler]

You guys think a little 12 volt NiCad pack would work? Something like the electric RC cars and airplanes use?

Or maybe modify a laptop battery... though now that I think about it I'm not sure Li-ion is the best idea for something that is constantly charging/discharging.

[kdo58]

if you look thru this thread this guy uses capacitors

http://pnwriders.com/pictures/139347-72-kawi-resto.html

[tkent02]

It wouldn't really charge and discharge much if you didn't use the electric starter.

[Graham]

You guys think a little 12 volt NiCad pack would work? Something like the electric RC cars and airplanes use?

No, the stock charging system eat a NiCad.

[tkent02]

No, the stock charging system eat a NiCad.

Why ?

[Graham]

Why ?

NiCad batterys don't charge like liquid cell batterys. Try it and see.

[tkent02]

Not going to try it and see until I find out how to make it work. Would you need to adjust the charging output to a different voltage? Again, there wouldn't be much charging and discharging if there was no electric starting.

[Steve]

As long as you don't have the high-discharge rate of the electric starter, a Ni-Cad battery would probably work better than lead-acid.

Having dealt with many different chemistries in hospital equipment over the years, I have learned that Ni-cads will happily charge and discharge at 1C, meaning their rated capacity for one hour. Using that rating, a 14Ah battery like most of our bikes could be fully charged from "dead" in just one hour, using a 14 amp charge rate. Most lead-acid batteries don't do well with a charge rate of greater than 0.1C, so the same battery would take 10 hours to charge because you could only use a 1.4 amp charge rate. (If you are in a hurry, a 0.2 or 0.3C rate can be used, but it's not as good for the battery.)

The charge rate on our bikes is not adjustable. It is actually rather amazing that out batteries last as long as they do,
given the loads (charge and discharge) to which we subject them.

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