Author Topic: Dropping the battery by the wayside  (Read 1953 times)

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Offline babyfood1217

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Dropping the battery by the wayside
« on: May 08, 2005, 11:43:22 am »
Another question on my crazy project bike.  So I've always enjoyed the look of older bikes which don't have batteries, and instead rely on kickstarts.  What I don't know is anything about bikes lacking batteries.  Are they able to run fine without the battery in them?  If the battery is removed, what else could therefore be gotten rid of?  Where could probelms arise from doing this?  Also, I am interested in changing to an H4 halogen lamp system, but am worried about the draw problems that may arise.  Would dumping the battery with a heavier draw lamp be a good idea?  So many questions, I hope there are so many answers...

-Chris Gerber
I need help moving my project bike from Wisconsin to Seattle, WA.  Willing to pay well.  Contact if interested.

SOHC member: #438

Project: 1976 CB750K
GSXR forks, Monoshock Rear end, 836 in progress, RC51 pipes, custom frame and everything else.

Offline kghost

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Re: Dropping the battery by the wayside
« Reply #1 on: May 08, 2005, 12:21:59 pm »
The Alternator system in theses bikes is not self exciting. Also the ignition requires battery power for starting.
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Offline Bob Wessner

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Re: Dropping the battery by the wayside
« Reply #2 on: May 08, 2005, 12:24:35 pm »
I recalled a post some time ago about battery elimination of 750's, thought you might be interested.
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Re: Dropping the battery by the wayside
« Reply #3 on: May 08, 2005, 08:45:29 pm »
I dont know if it could be done, but magneto ignitions do not require a battery. This is how motocros bikes work.  I had an old yamaha enduro that used magneto.


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Re: Dropping the battery by the wayside
« Reply #4 on: May 09, 2005, 09:40:57 am »
Given your level of mechanical aptitude and masochism it's absolutly possible, but not at all trivial.

If you start digging on the left side of your engine, remove the stator and rotor and you're left with a large enclosed space under the cover with one end of the crankshaft right there to power things.

Construction/retrofitting of a suitable generation system is trivial profided you've got the tools and knowhow to actually fabricate something from scratch. The engine has more then enough availible power to run a good sized generator.

However (and I'm a guy who plays with electricity for a living and looks at the complete rewiring of a 550 from SCRATCH as a trivial 2 hour job), I wouldn't do it myself, it's not worth the work involved.

Chris "Kicked in the Joules" Boden

Offline merc2dogs

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Re: Dropping the battery by the wayside
« Reply #5 on: May 10, 2005, 11:39:35 am »
set yourself up a micro-generator, a few small coils of wire, with a magnet set up on one of the spinning parts, a couple diodes to keep the power flowing in the right direction, tag that into the alternator feild wires, and the act of kicking will produce enough juice to get the alternator going normally.
 Also, have heard of people setting up a magnet inside the alternator to excite the feild enough to start working.
 You'd still need the cap though, as power would be pulsed, and the cap would/should smooth it out.

 If you just want to get rid of the bulky stock battery, use a small pack of nicads or nimh batteries, friend had a setup like that on his bike, panasonic cordless drill 15.2v battery pack that he tore apart and mounted in a couple of tubes,  worked nice, used a zener diode to manage charging on it.


Offline ride_a_honda

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Re: Dropping the battery by the wayside
« Reply #6 on: May 18, 2005, 08:59:20 pm »
Hello everyone,

I read this post a little while back and remembered seeing some info on this. I went searching for this info. Here is what I have found. Boyer Bransden has a unit called "The Power Box". It is designed to work with or without the battery and on cycles running both magnetos and alternators. They come in Single phase, Two phase and Three phase for most Brit Bikes, French and Italian as well as the majority of Japanese bikes with 3 wire alternators. I have scanned both sides of the info sheet I have on this product and can e-mail them if asked. Just e-mail me at "" and I'll send them. Be advised that this will be a 3 meg sized attachement.

1973 CB750K2 (build date 09/72) S/N 2063462
Currently being restored, still.......!
So much work left to little time!

After a short hiatus...I'm back in restoration mode!

Offline neckyzips

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Re: Dropping the battery by the wayside
« Reply #7 on: May 18, 2005, 10:41:33 pm »
hey guys,
this looks like it will do the trick! very small, check it out and tell what you think?