Re: Light research (silliness)

[Heather & Jeff <hjr@buffnet.net>]

> From: shields@tembel.org (Michael Shields)
 > So what voltage are headlight bulbs designed to run at?
> 
> All the replacement light bulbs I have ever seen say
> "12 Volts, XX Watts".
> 
> Luis
> 

The "12 volt" reference only refers to the general range of the system,
and is the only standard number you will find when talking about
charging systems.  Most battery chemistries in use today output
approximately 12.6 volts when "fully charged, room temp, float voltage
removed".  Alternator voltage must be higher than this to accept a
charge.  Too low, no charge or slow charge.  Too high, boiling of
electrolyte or worse.  There is no standard, but many alternator
manufacturers (including Bosch, who make Audi alternators) set at 14.0
volts.  ( I have seen from 13.5 to 14.5 used as set points.)

I do not know if there is a "pseudo-standard" among the light mfrs, but
I would guess they use 14.0 as a operating voltage (especially Bosch and
Hella, since Bosch sets their alts at 14.0)

Again, a few tenths of a volt makes a big difference in light life, but
a little difference in light brightness.

Jeff

'88 80q