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Blood Sweat Tears and Grease => Engines => Topic started by: bracketmaker on Feb 18, 2019, 16:13:11

Title: dyna ignition without a battery?
Post by: bracketmaker on Feb 18, 2019, 16:13:11
do any of the Harley guys or anyone know the answer. does anyone run an electronic ignition without a battery or is points the only way to do it.
Title: Re: dyna ignition without a battery?
Post by: bracketmaker on Feb 19, 2019, 15:10:32
went on chop cult. looks like some bikes can and some can't and it depends on the charging system. many run a small battery. the answer is that the dyna uses twice the current as points. the bike in question has trouble at idle with a 30w headlight so its not going to happen.

Title: Re: dyna ignition without a battery?
Post by: irk miller on Feb 19, 2019, 18:23:55
went on chop cult. looks like some bikes can and some can't and it depends on the charging system. many run a small battery. the answer is that the dyna uses twice the current as points. the bike in question has trouble at idle with a 30w headlight so its not going to happen.
Sorry, I meant to respond.  The other caveat is when the draw occurs and consistent supply is important.  You can supply it with a capacitor, though.
Title: Re: dyna ignition without a battery?
Post by: teazer on Feb 19, 2019, 18:35:15
Looks like you have found the answer already.  I'm not familiar enough with teh charging system of that bike to comment, but in general you are right that a DYNA ignition draws more current than good old fashioned points and without a battery to supply power at low revs, you risk not getting the bike started, let alone running consistently.

A capacitor will help to smooth out the pulsing effect of running it straight off the charging circuit but is unlikely to provide enough power at low revs.

That said, you can always try it and see if it runs or if it's too hard to start or drops out when you come to a halt. If it won't work without a battery, time to fit one. 
Title: Re: dyna ignition without a battery?
Post by: bracketmaker on Feb 21, 2019, 02:35:19


A capacitor will help to smooth out the pulsing effect of running it straight off the charging circuit but is unlikely to provide enough power at low revs.


sorry I didn't say I'm running a capacitor already. its a cheap audio part that does not supply more current, its not a battery even though it has the same function. it smooths out the pulsating DC wave but more important it shorts out any AC. its the path for AC to ground. a capacitor stores DC current like a battery but AC passes through.

thanks for getting back to me. its good to hear points are still good for something from others.