Capacitor instead of battery

carbonone · Jun 5, 2006

Ok guys. Before I try to reinvent the wheel..........

Has anyone replaced their battery with a capacitor for hot start use only?

Even when all is right with ignition, timing, valves, etc the battery is not strong enough to really turn the motor fast enough to fire.....even hot.

I have seen tons of threads on the subject and a picture of a cap behind a guys light ON This sight 8O

How do you do this? What kind of discharge circuit will allow me to use a higher voltage Cap (40-65V) to quickly turn the motor without frying the starter? What kind of charge circuit do I need to recharge the cap without taking too much power away from the stator for spark?

Unfortunately I have just enough electronics expertise to be dangerous.

If anyone can shed some light on this, please let me know.

thanks

JoeUSA · Jun 5, 2006

Sorry Ryan, no, no, no.

Read Bundybear's post in this thread!

http://www.husaberg.org/modules.php?nam ... =capacitor

Regards,

Joe

p.s. The battery charging/lights powering part of the SEMs ignition system is separate from the part of the SEMs that provides power for the ignition. Running the lights does not affect your spark!

Maddel · Jun 5, 2006

Well, I'm the guy who mounted a cap behind the headlightmask... :wink:
The reason why is perfectly described by Bundybear below...

(Just inserted his post from the above mentioned thread... Thanx Joe!)

One more note (applies for road-legal electrics with turn signals):
The cap also helps to increase the regulator/rectifiers "lifespan".
It "simulates" a battery so the regulator/rectifiers gets not that hot....

Bundybear said:
Sorry to not get to it sooner but even the largest capacitor available is still about a billion times too small to crankstart an engine and even a few million times too small to run lights for any length of time. That is why there still is not much alternative to a battery.

When a capacitor is used to replace a battery it only "smoothes" out the DC pulses that come from the rectifier so that the electrical system works while the engine is running. It can only supply power to the electrix for the time it takes from one AC cycle to the next - perhaps 3 milliseconds. In that time it will lose about 10% of its voltage. It cannot be used as an energy store.

You can probably remove the battery & starter OK without worrying about a capacitor. The capacitor is really only needed if you use any electronic items on the bike such as a electronic turning indicator flasher unit. Hot wire flasher units - little aluminium cans - seem to work OK. The horn still works without a capacitor but sounds like a sick cow.

You can expect to see the lights go a bit dim at idle, but this usually isn't a problem and they work OK without a battery. Of course if the road rules in your part of the world require that the lights keep lit when the engine stalls (they tried to bring that in here 10 years ago but failed) then you have no chioce but to fit a small battery.

I've had a KTM & a Husky with full road-legal electrics, no battery and no capacitor. I had another KTM that used an electronic flaher and was fitted with a 4700 microfarad @35V capacitor from the factory.

LINEAWEAVER · Jun 7, 2006

For What It May Be Worth:

With the majority of full phase charging systems (in particularly tri phase) and a 56,000 uf capacitor I have successfully run many Engine Management Systems. (ie fuel Injection)

Unfortunately such will not help you get the engine started. :?

Dale

Capacitor instead of battery

Help Support Husaberg:

carbonone

JoeUSA

Maddel

LINEAWEAVER

Similar threads

Register CTA

Recent Discussions

Recent Discussions