Lights

[kiwi]

wht is the actual voltage of a fully charged "12v lead acid"

[AndySV1K]

fully charged with no load attached you should be looking at 12.5-13v

Andy.

[AndySV1K]

**update**

Those that have posted here who have HID lights, im after a bit of info.

How do they cope with heat dissipation?

Can you run them for long while stationary?

I know that the old Cygolight halogens that i used to run with double the output to stock couldn't be run for long whie stationary as they got hot very quickly! they were fine when moving and dissipated heat quite nicely, they would happily run for a full charge worth while cycling.  I never overheated them, but i just had the feeling something was going to melt if i ran them too long while stood still.

Well, i have just finished a prototype HID, its in a very compact fitting with an external ballast.

I have very roughly tested their operating life using a 7Ah battery (lead acid at the moment) it will run for just under 2 hours from a full charge.  That  was just the lamp on its own, now its in the fitting i dont want to run the same test again as i think it will generate too much heat to run safely indoors.  The next batt life test will have to be on the bike (when its built)

I opted for a 35w xenon at 6000K its a nice white light with a hint of blue, but not so much that light output is badly affected.

Just carried it to the garden and it lights up the whole garden nicely! cant wait to try it on the bike.

Still to do...

Find a handlebar mount for the light fitting.

Find a frame bag of some sort to house a battery and the ballast.

Oh, and fit a switch to it.

If anyone knows of some handlebar mounts that might help i'd be grateful for a link or info.  the fitting has a flat plate with holes for fixing.

Andy.

[kiwi]

maybe have a external cooling fan fan running while you test??(fine if you have one!)

[AndySV1K]

Could do, although to be honest its not far off being able to go onto a bike.

then i can test it properly, as that will give realistic airflow, vibration etc to test everything

Andy.

[jimbo]

Carry a spare (cheap light) when using a HID.  Some of them have finicky ballasts.

[AndySV1K]

How do you mean finiky?

Do you mean they fail?

I cant vouch for the long term life of the unit im using yet, but its an automotive product and therefore designed for pretty tough conditions.

Ive pullled one to bits and couldnt get any further than taking the lids off as the whole thing is molded solid in silicone so theres no movement at all.

Andy.

[jimbo]

How do you mean finiky?
Andy.

Friend showed up with this $400 HID system.  Super bright and impressive.  Went on a ride.   Half way through the ride after a rest stop the HID would not restart.  Loaned him my spare I double AA battery light I carry as a back up.   Dam thing started to work when we got back to the cars.  Like I said Finicky.  He had one of the first HID system so it might have been bugs that hopefully got worked out.

[AndySV1K]

Maybe it was battery life.

They consume an awfull lot of power on start up, most have a strike time of around 20 seconds and the ballast has to initially generate very high voltages.  Perhaps by the time the you finished the ride, the battery had recovered slightly.

who knows!

Andy.