How to calculate battery size needed?

[kwaka_crasher]

In answer the to the why here it is....

Gilera Saturno Bialbero Superleggera 558 project outline.

Seems like a pointless waste of time for a road bike to me, but whatever floats your boat.

But back to the question: Like I said, unless you're planning on spending lots of time putting around town at low rpm you don't need much of a battery at all - the alternator will provide all the power you need - the battery is just for starting and as a buffer.

[gavinnz]

Seems like a pointless waste of time for a road bike to me, but whatever floats your boat.

But back to the question: Like I said, unless you're planning on spending lots of time putting around town at low rpm you don't need much of a battery at all - the alternator will provide all the power you need - the battery is just for starting and as a buffer.

I have the time and the point is I enjoy the creative process of doing it.
And I will enjoy the lighter more responsive and unique bike.
A lot of the best things in live are pointless...

Later
G

[AllanB]

Sounds like a cool project to me.

Now don't forget to put the rider on a diet too

PS - batteries are surprisingly heavy!

[CookMySock]

Hm. Headlamp hardwired limits things.

He needs some diodes and a relay so the headlight comes on when the stator starts producing output.

I'd try a bunch of AA penlight cells in a 12V holder and see if it would allow you to start the bike. If it did, then try some NiHM cells.

http://jaycar.co.nz/productView.asp?ID=PH9209

Don't run the carbon penlight cells for very long coz charging them will pop them.

Steve