Is there any good non-rechargeable headlights anymore?

On Mon, 15 May 2017 06:06:27 -0700, sms
wrote:

On 5/13/2017 4:52 PM, Jeff Liebermann wrote:
On Sat, 13 May 2017 16:33:40 +0000 (UTC), Ralph Barone
wrote:

"A thing of beauty and a joy to behold."
Not quite...

I beg to differ. The uglier it looks, the better it works. When I
see a beautiful work of mechanical art, I suspect that something
important has been sacrificed to gods of art and beauty. It might be
a joy to behold, and simultaneously be pure hell to operate. It's
much like concept bicycle designs, which (to me) are generally quite
beautiful, but also impossible to ride.

Form follows mal-function:
http://802.11junk.com/jeffl/pics/bicycles/slides/bicycle-flashlight.html
Incidentally, the Maglite in the photo is no more. I tried to use it
last night and discovered that the D cells had leaked and are now
corroded and firmly stuck in the flashlight tube. Sniff...

Time to join the 21st century. Get yourself to Costco.

Most of my Maglites are 20+ years old. (The company is 38 years old).
Some were repaired for switch problems under the lifetime warranty.
Try that with what's available today. However, I don't think I'll
live another 20+ years, so I'm currently buying cheap junk flashlights
on eBay.

Costco is currently selling Duracell flashlights.
https://www.costco.com/Duracell-2-pack-LED-700-Lumens-Flashlight-.product.100319990.html
700 lumens seems slightly less fanciful than the previous 1000 lumen
claim. I haven't tested any, but I don't believe that 700 lumens from
3ea C cells is possible.

Assuming a typical 75 lumens/watt LED, the battery would need to
deliver
700 lm / 75 lm/watt = 9.3 watts.
3 cells is about 4.5volts, so that's:
9.3 watts / 4.5v = 2.1 amps
From the data sheet at:
https://www.costco.com/Duracell-2-pack-LED-700-Lumens-Flashlight-.product.100319990.html
a single C cell is essentially dead drawing 2A for 15 mins. 3 cells
in series at 2A have the same 15 min discharge time. The light
probably operates much longer than 15 mins, which suggests that the
700 lumens is still rather fanciful.

From the reviews section:
Great illumination, nice design. I just wish the flashlight
worked. I've had 8 of these, and every single one ceased
working anywhere between 1 week and 7 months after purchase.
...
The replacements I received from the vendor's customer
support all were DOA.

The real problem is the alkaline battery which does badly at the high
currents needed to run a really bright LED. A large flashlight these
daze should be using some flavor of LiIon or at least LSD NiMH
batteries. Duracell is using these flashlights as a gimick to sell
alkaline batteries.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 5/15/2017 9:41 AM, Jeff Liebermann wrote:
On Mon, 15 May 2017 06:16:07 -0700, sms
wrote:

On 5/14/2017 7:22 PM, Jeff Liebermann wrote:

True. I retrofitted my various 2D and 3D Maglites with aftermarket
LED conversions. The reflector design was obviously all wrong but
worked well enough to be usable. There are now Maglite conversion
kits which replace everything from the light bulb, to the entire head
assembly.

Convert your film camera to digital too: http://www.siliconfilm.com/

$700. For that, I can buy a fairly decent digital camera. The sensor
size is not specified, but I doubt it will cover the entire 36x24mm
frame size.
http://www.siliconfilm.com/faq.htm
http://www.siliconfilm.com/fov.htm
Resolution is 1.3 megapixles (1280x1024 in 36 bit color) but no clue
if that's the sensor resolution or if it has been upscaled from a
smaller sensor. Probably useful for someone who has a large
investment in a compatible film camera system.

It never came to market other than some prototypes. There were so many
issues with it that of course it was never going to work.

On 5/15/2017 10:11 AM, Jeff Liebermann wrote:

snip

The real problem is the alkaline battery which does badly at the high
currents needed to run a really bright LED. A large flashlight these
daze should be using some flavor of LiIon or at least LSD NiMH
batteries. Duracell is using these flashlights as a gimick to sell
alkaline batteries.

And I had one of the Duracell 4C models which self-destructed with NiMH
batteries.

On 5/15/2017 9:30 AM, Jeff Liebermann wrote:

snip

https://en.wikipedia.org/wiki/Eneloop
Using 4th generation numbers:
AAA 3 cells * 800 ma-hr * 1.5v = 3.6 watt-hrs
AA 2 cells * 2000 ma-hr * 1.5v = 6.0 watt-hrs

For a light that you're using every day, there's no upside in the
Eneloop batteries. They reduce self-discharge with a separator that is
thicker, decreasing the volume of chemicals. But if you're charging
every day anyway, self-discharge is not an issue. Also, the Eneloop Pro
AA are about 2500mAH and there are non-low-self-discharge NiMH cells
that deliver 2700mAH. The Eneloop Pro AAA are about 950mAH.

On Mon, 15 May 2017 10:26:17 -0700, sms
wrote:

On 5/15/2017 10:11 AM, Jeff Liebermann wrote:

snip

The real problem is the alkaline battery which does badly at the high
currents needed to run a really bright LED. A large flashlight these
daze should be using some flavor of LiIon or at least LSD NiMH
batteries. Duracell is using these flashlights as a gimick to sell
alkaline batteries.

And I had one of the Duracell 4C models which self-destructed with NiMH
batteries.

That makes me wonder what marginal circuit Duracell used for an LED
driver. The LED driver is suppose to be a current regulator matched
to the LED power rating with a PWM modulator for controlling
brightness. As long as the driver can handle the applied voltage, the
current should be the same for alkaline and NiMH batteries. My
guess(tm) is that:
1. Duracell did something stupid, like use a 3 cell LED driver (4.5V
max), in a flashlight with 4 cells (6.0V max).
2. Maybe the NiMH batteries actually delivered enough current to
drive a really bright LED but cooked the LED driver by dissipating too
much power.
3. Didn't use power saving PWM to control brightness, but instead
used an inefficient linear regulator. Got a photo diode and an
oscilloscope? Try looking at what the dimmer circuit is doing.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 5/15/2017 4:30 PM, Jeff Liebermann wrote:

snip

And I had one of the Duracell 4C models which self-destructed with NiMH
batteries.

That makes me wonder what marginal circuit Duracell used for an LED
driver. The LED driver is suppose to be a current regulator matched
to the LED power rating with a PWM modulator for controlling
brightness. As long as the driver can handle the applied voltage, the
current should be the same for alkaline and NiMH batteries. My
guess(tm) is that:
1. Duracell did something stupid, like use a 3 cell LED driver (4.5V
max), in a flashlight with 4 cells (6.0V max).
2. Maybe the NiMH batteries actually delivered enough current to
drive a really bright LED but cooked the LED driver by dissipating too
much power.
3. Didn't use power saving PWM to control brightness, but instead
used an inefficient linear regulator. Got a photo diode and an
oscilloscope? Try looking at what the dimmer circuit is doing.

There had to have been a board in there because there were multiple
power levels, and flash mode.

The light came on very bright, for a few seconds, before destroying the
LED or the driver.

On Mon, 15 May 2017 17:14:28 -0700, sms
wrote:

There had to have been a board in there because there were multiple
power levels, and flash mode.

Yep. Something like this:
http://www.ebay.com/itm/222134093111

The light came on very bright, for a few seconds, before destroying the
LED or the driver.

Sounds about right for overheating. Over voltage would blow it up
instantly, while overheating takes some time. The usual culprit for
overheating is lousy heat sinking on the LED or regulator circuitry.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

UMBUGWA FUGOOODO ?



https://en.wikipedia.org/wiki/Eneloop

On Monday, May 15, 2017 at 3:22:28 PM UTC-7, sms wrote:
On 5/15/2017 9:30 AM, Jeff Liebermann wrote:

snip

https://en.wikipedia.org/wiki/Eneloop
Using 4th generation numbers:
AAA 3 cells * 800 ma-hr * 1.5v = 3.6 watt-hrs
AA 2 cells * 2000 ma-hr * 1.5v = 6.0 watt-hrs

For a light that you're using every day, there's no upside in the
Eneloop batteries. They reduce self-discharge with a separator that is
thicker, decreasing the volume of chemicals. But if you're charging
every day anyway, self-discharge is not an issue. Also, the Eneloop Pro
AA are about 2500mAH and there are non-low-self-discharge NiMH cells
that deliver 2700mAH. The Eneloop Pro AAA are about 950mAH.

This sounds like exactly the thing for a bicycle headlight.

On 5/16/2017 7:26 AM, wrote:
On Monday, May 15, 2017 at 3:22:28 PM UTC-7, sms wrote:
On 5/15/2017 9:30 AM, Jeff Liebermann wrote:

snip

https://en.wikipedia.org/wiki/Eneloop
Using 4th generation numbers:
AAA 3 cells * 800 ma-hr * 1.5v = 3.6 watt-hrs
AA 2 cells * 2000 ma-hr * 1.5v = 6.0 watt-hrs

For a light that you're using every day, there's no upside in the
Eneloop batteries. They reduce self-discharge with a separator that is
thicker, decreasing the volume of chemicals. But if you're charging
every day anyway, self-discharge is not an issue. Also, the Eneloop Pro
AA are about 2500mAH and there are non-low-self-discharge NiMH cells
that deliver 2700mAH. The Eneloop Pro AAA are about 950mAH.

This sounds like exactly the thing for a bicycle headlight.

Self-discharge occurs over weeks and months, not days. The Eneloop NiMH
batteries are good for devices that are used only occasionally, but
unnecessary for devices that are used daily.

But if you only ride at night very occasionally then the Eneloops are a
good choice.

That said, the Eneloop Pro batteries are only about 10% lower capacity
than non-low-self-discharge NiMH cells, and they are about $1 per cell
more than name-brand 2700 mAH NiMH AA cells. 2700 mAH appears to be the
practical limit for NiMH AA cells, even though there are some cells that
claim 3000 mAH, but they lie.

But the reality is that a rechargeable, Li-Ion, 18650 powered, light is
a much better option for most people. They are smaller, brighter, and
cheaper. But you can't run into a 7-11 or a gas station to buy
replacement batteries.

Carrying along a spare Li-Ion cell is no more difficult than carrying
along a bunch of AA cells, in fact it's actually easier. Though you
can't buy an 18650 at the corner store, Fry's often has 18650 2600 mAH
(9.6 WH) Tenergy cells for $4.99, and they have very low self-discharge.
For $20 you can buy a perfectly decent bicycle light, including an 18650
battery (but probably a pretty low capacity one), and you can charge it
with any charger that has a Micro USB plug. If you want to charge it
from a dynamo there are adapters with which to do so.