bullets on a pre war bike

[ken]

I am impressed with the bullets I bought ,intended for a later bike on 12v neg earth.

I have a 1938 bike on 6v neg, while I realise there is not enough grunt from my 6v, in view of the low consumption of the bullets I am toying with the idea of using a small dry 12v battery, possibly in a small case on the forks.

right now I am wondering about the sort of battery that's used on power tools, neat, well encased not too bulky,  and capable of hold a charge for a long time but all I have are 14v, how would the bullets stand up to that?

you'll appreciate on an older bike its not really practical to keep lights on all the time and they are just as vunarable to smidsys as newer ones.
other than that its a raid on maplins.

views please.

[Fluke]

Hi Ken

A battery could work as the Bullets consume so little power. The very best solution would be a Lithium (Li-poly) based pack but even that is probably overkill.

Have you thought of sourcing a complete lighting system designed for Bicyles ?, reason is these often have rechargable packs with them and would suit the application in this respect perfectly with minimal work.

Regard

[ken]

Thanks
Overkill is fine where my neck is concerned, I will check out bike lights, I have period lamps fitted, fine after dark when alone but they are not up to todays dazzle.


if results work will update.

how will they stand up to 14volts?

[RCE]

You would be better getting or making a stepup inverter


Make one [size=78%]http://www.aaroncake.net/circuits/6-12conv.asp[/size] or [size=78%]http://www.electronicecircuits.com/electronic-circuits/6v-to-12v-converter[/size]


Buy one [size=78%]http://www.ebay.co.uk/itm/Classic-car-6V-12V-voltage-converter-power-power-/350436684000[/size]

[Fluke]

Very neat idea :)   ... always forget these, a simple solution.

[ken]

My electronic skill stops at joining wires up, plus I don't really have a lot of 6v battery.

what I am looking at is one of these

ebay 250920312233

or 390460537069

when it come to working out consumption or how long two bullets will last on one of these then my brain hurts.

[I can't cut paste into this site]?

[RCE]

Pretty simple calc, each bullet 72mA = 144mA total load.


2800mAh battery divided by 144mA = 19 hours so you should get 12 hours out of that battery pack easy.

[ken]

excellent thanks, 12 hrs more than enough

simple for you maybe... but I've only just weaned off gas lights