Page 1 of 2
running without battery?
Posted: Fri Jan 13, 2012 10:19 am
by cncltd1973
I've been searching for someone who's addressed this issue, but haven't come across anything. My 75/5 kickstarts easily, my battery isn't worth anything, and besides, I think the bike looks better without the chrome covers and battery. So is it possible to wire without the battery?
Re: running without battery?
Posted: Fri Jan 13, 2012 9:00 pm
by George Ryals
I think that you need some juice to excite the field of the alternator to start the generation of power to run the ignition,and lights. So I don't think, without serious modification like a different charging system that a /5 can be run without a battery.
Re: running without battery?
Posted: Fri Jan 13, 2012 9:05 pm
by Major Softie
Nope. The bike's alternator doesn't make enough current when kicked over to start the bike. You need at least a small battery to provide starting ignition. But, if you never intend to kick-start it, you can get away with a pretty tiny battery. If you have put any kind of electronic ignition on the bike, you may need even more current for it to work, and they can be very voltage sensitive too, but for points ignition you don't need much.
That's the big advantage of magneto ignitions: they will even work at the very low kick-starting rpm with no battery.
I forgot George's point about exciting the fields. I just know the bike won't start.

Re: running without battery?
Posted: Sat Jan 14, 2012 12:25 am
by Garnet
From first hand experience I can say, "If the gen light does not glow, the bike won't start." It doesn't take much juice ( as MS stated) but you need some.
Also, a tiny battery in good condition is better than a nakerd stock battery for the alternator.

Re: running without battery?
Posted: Sat Jan 14, 2012 2:30 am
by Duane Ausherman
You do not want to have to depend upon using the kick start function. Use the electric start.
Re: running without battery?
Posted: Sat Jan 14, 2012 12:02 pm
by Chuey
vanzen made a small battery and uses that in his Old Crow project bike. It is about the size of two or three cig packs. He has some info on his project but possibly not specifically on the battery on his website:
www.rockerboxer.com. If that isn't quite accurate, you can google rockerboxer and it will come up.
Chuey
Re: running without battery?
Posted: Sat Jan 14, 2012 1:01 pm
by jagarra
I ran without a battery on my old Triumph for many years, even though it has a alternator, rectifier, zeiner diode system. The addition of a capacitor on the output of the rectifier allowed me to do it. Of course it is a kick start only so, that was the method of introducing voltage into the system. Since then I had to add a small battery as it makes it easier to start and run smoother as the battery evens out the electrical pulses that fire the coils. Before I did this, it started to misfire higher RPMs. I would keep the battery in the system.
Re: running without battery?
Posted: Sat Jan 14, 2012 2:20 pm
by cncltd1973
I found this this lithium 4 cell battery, used in scooters and tested up to 1800cc. It's 2x2x3.25" and might fit at the end of the ignition coils and hide entirely, but I haven't measured it yet.
http://www.amazon.com/BALLISTIC-PERFORM ... B005WXPUDW
Re: running without battery?
Posted: Sat Jan 14, 2012 2:37 pm
by mattcfish
Lithium Iron batteries are what the Cafe crowd is switching too.
http://www.ballisticparts.com/
Very tiny and about 10 pounds lighter.
I've seen them slung under the back of the transmission or under an after market seat hump. They may even fit under the tank with some modifications.
I've heard that the kick starts on airheads are basically for emergencies. They break very quickly if used too regularly.
Re: running without battery?
Posted: Sun Jan 15, 2012 10:08 am
by cncltd1973
I just ordered the Ballistic Evo2 8 cell battery. The dimensions should fit under the tank, behind the coils. And with 275CCA, I won't be kickstarting anymore. Will post again with the final result, Thanks for the input.