Dynamos vs. LEDs (Re: Cyclist Explodes! (NW Cambridge Plans))




>
> Why "dynamos not allowed"?


Because while we have dynamos most people do not want to spend enough
to get a good one that always works, nor put one on all their bikes.If
you have to park a rough bike in a bad place it would be a bad idea
anyway.
It really should be recognised by the law that there are plenty of
good, cheap ,convenient battery lights now and they are what people use
and they do so because it's the right choice for them.I can see no
reason not to recognise many of the current crop of lights beyond
beaurocratic sluggishness.
Sorry to trouble you with my rant, I know it's not your fault.
TerryJ
 
In article <[email protected]>,
Don Whybrow <[email protected]> writes:
|>
|> A few thought spring to mind:
|> 1) Which company only claims 400?
|> 2) How long ago was this?
|> 3) Are you sure it was for NiMH & not NiCad?
|> 4) Even if the figure I quoted is optimistic, one should expect at least
|> half that amount.
|>
|> It would be nice to see some evidence for the first 3 at least, URL's,
|> that sort of thing to back up your assertions.

Oh, ye of little faith:

http://www.batterycanada.com/Battery_Facts.htm


Regards,
Nick Maclaren.
 
Nick Maclaren wrote:
> In article <[email protected]>,
> Don Whybrow <[email protected]> writes:
> |>
> |> A few thought spring to mind:
> |> 1) Which company only claims 400?
> |> 2) How long ago was this?
> |> 3) Are you sure it was for NiMH & not NiCad?
> |> 4) Even if the figure I quoted is optimistic, one should expect at least
> |> half that amount.
> |>
> |> It would be nice to see some evidence for the first 3 at least, URL's,
> |> that sort of thing to back up your assertions.
>
> Oh, ye of little faith:
>
> http://www.batterycanada.com/Battery_Facts.htm


OK, so we have a distributor claiming 400 and a manufacturer claiming
1000 although the distributor also mentions 1000 at
http://www.batterycanada.com/Digital_Camera_Battery.asp. Looks to me
like the 400 is wrong.

--
Don Whybrow

Sequi Bonum Non Time

"To communicate with Mars, converse with spirits, To report the
behaviour of the sea monster, Describe the horoscope, haruspicate or
scry, Observe disease in signatures." (T.S.Eliot)
 
In article <[email protected]>,
Don Whybrow <[email protected]> writes:
|>
|> OK, so we have a distributor claiming 400 and a manufacturer claiming
|> 1000 although the distributor also mentions 1000 at
|> http://www.batterycanada.com/Digital_Camera_Battery.asp. Looks to me
|> like the 400 is wrong.

From other reading, it is more likely that the 1,000 is, in practice.

The 400 is likely to be the minimum lifetime under realistic (i.e. poor)
usage conditions; the 1,000 under near-optimal ones. There could also
be a factor that the former is until significant degradation, and the
latter until degradation beyond realistic use.

It's not actually relevant in practice, as other people have pointed out,
as few batteries will be used for that long before being lost, stolen
or abandoned (possibly because the unit fails and its replacement needs
a different size).


Regards,
Nick Maclaren.
 
Changing the subject back to LED efficiency for a moment:
http://www.cree.com/press/press_detail.asp?i=1160427137863
"XLamp LEDs now as efficient as fluorescent sources [...]
luminous flux of up to 95 lumens or 85 lumens per watt at 350
mA, and up to 160 lumens at 700 mA.
Typical luminous flux for the new Cree XLamp 7090 LED is 80 lumens at
350 mA, yielding 70 lumens per watt."
 
"Anthony Jones" <[email protected]> wrote in message

> Sounds like the B&M Ixon. I suspect most people would baulk at the price
> (£75 with charger from www.kinetics.org.uk) though...


I Imported one from germany with charger and batteries for about £51. It's
excellent for a removable light.

Jc.