Thumper Club Forum

Technical => Bike Problems/Questions => Topic started by: guest27 on April 20, 2010, 07:51:54 PM

Title: Battery elimination
Post by: guest27 on April 20, 2010, 07:51:54 PM
Hi Peeps who understand electric pixieese

I have been given a box of big capacitors to see if any will suffice for the battery elimination gig.

I want to do this on 6v and 12v bikes.

I understand I needs lots of uF - I have variously seen 4500, 16000 and 20000 suggested.

I also understand that I need spare volts on the spec, I have seen 40v suggested for 12v applications.

Now I have here 2 off 85000 uF 16v DC - loads of uF (too many?) but will 16V be sufficiant for a 6V application?

I have several 4500 uF 40v DC - loads of V for 12v but are there enough uF? - can I use two capacitors in parallel and have double the uF at the same V?

Thoughts please

R
Title: Re: Battery elimination
Post by: guest146 on April 21, 2010, 05:10:14 PM
Is a capacitor the normal way of fitting lights to a non battery bike? Its the first time i have heard of this. If you have spare power from you engine generator can you not just pipe min a regulator and a battery?

Ken
Title: Re: Battery elimination
Post by: Bojer on April 21, 2010, 06:51:56 PM
Yes you can use two of your caps. in parallel to double up the uF but when I have tried similar arrangements or just running a zener diode etc I have found a battery does a good job in comparison ! Try it and see how you get on - add more caps as you feel the need !

I found that a small sealed alarm battery - very similar to the ones used in the work alarms that are replaced regularily  ;) do a great job and hold charge well too , as you'd expect .  8)
Title: Re: Battery elimination
Post by: guest27 on April 22, 2010, 09:43:06 AM
Hummm we get a number of UPS sealed units through - mind I was comparing the weight of a cap with a LA battery...

R
Title: Re: Battery elimination
Post by: Bojer on April 22, 2010, 01:31:17 PM
The cap is smaller and lighter true - I have used one with success - even on a bike that was battery coil ignition it was good enough to run the bike - but low revs with lights or indicators etc would misfire/cut out !

If its for a bike without indicators I think a cap is a good solution especially if its a bike that is not used every day - I should be getting a BSA B40 trials bike soon so might give it a try on that - thanks for the reminder !
Title: Re: Battery elimination
Post by: Steve H on April 22, 2010, 02:54:44 PM
I should be getting a BSA B40 trials bike soon.

Do you compete in Pre-65 trials ?. You sig also says you have a DT, excellent bikes, I used to do long distance trials (not the MCC ones) on the DT.
Title: Re: Battery elimination
Post by: Bojer on April 22, 2010, 08:28:20 PM

[/quote]

Do you compete in Pre-65 trials ?. You sig also says you have a DT, excellent bikes, I used to do long distance trials (not the MCC ones) on the DT.
[/quote]

Not yet ! But that's the plan , been trail riding for a long time and Rallies etc but fancied a change and have never tried trials .  Still have the DT , stripped down and shotblasted the frame and its slowly going back together - as you say great bikes - bought my first one brand new for £659 OTR - shows I AM getting old !
Title: Re: Battery elimination
Post by: guest27 on April 23, 2010, 11:34:31 AM
Fancy a DT250 / 400 chassis for a Maico lump I have hanging about - Used to have a 125, a 157 and a 250 - all great bikes

R
Title: Re: Battery elimination
Post by: Steve H on April 23, 2010, 12:20:07 PM
Fancy a DT250 / 400 chassis for a Maico lump I have hanging about - Used to have a 125, a 157 and a 250 - all great bikes

R

Embarrassingly my DT175 is stored in the loft. Haven't the heart to sell it, and since its been hacked about quite a bit with trials mods, its not worth much anyway.