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Battery Replacement on Lights with Internal Li-Ion Batteries



 
 
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  #61  
Old February 9th 18, 08:01 PM posted to rec.bicycles.tech
Ian Field
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Posts: 248
Default Battery Replacement on Lights with Internal Li-Ion Batteries



"Tosspot" wrote in message
...
On 08/02/18 23:05, Ian Field wrote:


"Joerg" wrote in message
...
On 2018-02-06 18:56, Frank Krygowski wrote:
On 2/6/2018 1:52 PM, sms wrote:
My wife's Lezyne Deca 1500XXL stopped taking a charge, at all. Taking
it apart, I saw that the batteries were made in July 2015. Not too
good for it to stop working that soon.

Some of my bikes have dynamos that are 30 years old. They just keep
going and going and going...


Until you get to a red traffic light, to a stop sign or into a traffic
jam. The perfect spot at night to get hit by a car driver who didn't see
you because you were on the only unlit vehicle around.


AFAIK: dynamo lighting is illegal in the UK for exactly that reason.


I do not think so. It may be the case that turning across traffic at
night you don't wait in the middle of the road, but stand lights have long
solved that.


Looks like what I was told was either wrong or out of date - but I have been
warned that a backup battery may not make a dynamo ant less illegal.

Ads
  #62  
Old February 9th 18, 09:35 PM posted to rec.bicycles.tech
SMS
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Posts: 8,194
Default Battery Replacement on Lights with Internal Li-Ion Batteries

On 2/8/2018 12:21 PM, Joerg wrote:
On 2018-02-06 20:48, Jeff Liebermann wrote:
On Tue, 6 Feb 2018 10:52:50 -0800, sms
wrote:


[...]


It's a 2 cell 18650 pack with the batteries in parallel, and a
protection circuit board shared between the two cells. The cells are
allegedly 2800mAH, for a total of 5600mAH.


Seems rather high.



Probably a Chinese spec :-)

Just like with lights where there are lumens and then there are Chilumens.


**************** ... Note that batteries are tested at a 0.2C
discharge, which yields larger numbers than the usual headlight
discharge rate.* The Lezyne Deca 1500XXL claims 1500 lumens, which
also seems a bit high.* Assuming 120 lumens/watt at a nominal
3.7V/battery, that's:
*** 1500 / 120 / 3.7 = 3.4A
to run the headlight at full brightness, or 1.7A per cell.
Meanwhile, the cell capacity is tested at:
*** 0.2 * 2800 = 0.56A


Classic American answer: Then you need a bigger battery. On my road bike
I use eight 18650 cells, four in parallel and two of those packs in
series so the current on the cable to the front light doesn't exceed 1A,
at least not by much.


I decided to do run-time tests on my two Lezyne Decadrive 1500xxl lights.

I think that I have never before experienced a light manufacturer that
significantly under-stated run times.

Running both in "Overdrive Race Mode" the run time was much higher than
the manual stated. mtbr.com measured "Overdrive Race Mode" at 1390
lumens, a little less than the claimed 1500 lumens. The manual says 100
minutes in "Overdrive Race Mode."

On the light with the new 5200mAH battery back, one test gave 157
minutes, one 162 minutes.

On the light with the old 5600mAH battery pack, one test gave 193
minutes, one test gave 216 minutes.

I did not run the battery all the way down. When the "10% remaining"
indicator occurred I stopped the test.

I am going to do a third test as well, as soon as the batteries are
recharged.
  #63  
Old February 10th 18, 12:10 AM posted to rec.bicycles.tech
Joerg[_2_]
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Posts: 5,107
Default Battery Replacement on Lights with Internal Li-Ion Batteries

On 2018-02-09 13:35, sms wrote:
On 2/8/2018 12:21 PM, Joerg wrote:
On 2018-02-06 20:48, Jeff Liebermann wrote:
On Tue, 6 Feb 2018 10:52:50 -0800, sms
wrote:


[...]


It's a 2 cell 18650 pack with the batteries in parallel, and a
protection circuit board shared between the two cells. The cells are
allegedly 2800mAH, for a total of 5600mAH.

Seems rather high.



Probably a Chinese spec :-)

Just like with lights where there are lumens and then there are
Chilumens.


... Note that batteries are tested at a 0.2C
discharge, which yields larger numbers than the usual headlight
discharge rate. The Lezyne Deca 1500XXL claims 1500 lumens, which
also seems a bit high. Assuming 120 lumens/watt at a nominal
3.7V/battery, that's:
1500 / 120 / 3.7 = 3.4A
to run the headlight at full brightness, or 1.7A per cell.
Meanwhile, the cell capacity is tested at:
0.2 * 2800 = 0.56A


Classic American answer: Then you need a bigger battery. On my road
bike I use eight 18650 cells, four in parallel and two of those packs
in series so the current on the cable to the front light doesn't
exceed 1A, at least not by much.


I decided to do run-time tests on my two Lezyne Decadrive 1500xxl lights.

I think that I have never before experienced a light manufacturer that
significantly under-stated run times.

Running both in "Overdrive Race Mode" the run time was much higher than
the manual stated. mtbr.com measured "Overdrive Race Mode" at 1390
lumens, a little less than the claimed 1500 lumens. The manual says 100
minutes in "Overdrive Race Mode."

On the light with the new 5200mAH battery back, one test gave 157
minutes, one 162 minutes.

On the light with the old 5600mAH battery pack, one test gave 193
minutes, one test gave 216 minutes.

I did not run the battery all the way down. When the "10% remaining"
indicator occurred I stopped the test.

I am going to do a third test as well, as soon as the batteries are
recharged.



Those numbers aren't bad indeed. However, they'd be totally inadequate
for many of my bike rides with 4-5h of riding time.

--
Regards, Joerg

http://www.analogconsultants.com/
  #64  
Old February 10th 18, 01:24 AM posted to rec.bicycles.tech
SMS
external usenet poster
 
Posts: 8,194
Default Battery Replacement on Lights with Internal Li-Ion Batteries

On 2/9/2018 4:10 PM, Joerg wrote:

Those numbers aren't bad indeed. However, they'd be totally inadequate
for many of my bike rides with 4-5h of riding time.


Yes, if you needed full power for the entire ride, which is unlikely on
a road ride.

Also, the lights I have are discontinued. The new models are better
because they combine an all-in-one sealed waterproof design with an
optional external power-pack. I greatly prefer an all-in-one design to a
design with a separate power pack, but YMMV.
http://www.lezyne.com/product-led-perf-deca1500i.php.
  #65  
Old February 10th 18, 02:01 AM posted to rec.bicycles.tech
JBeattie
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Posts: 3,059
Default Battery Replacement on Lights with Internal Li-Ion Batteries

On Thursday, February 8, 2018 at 12:21:15 PM UTC-8, Joerg wrote:
On 2018-02-06 20:48, Jeff Liebermann wrote:
On Tue, 6 Feb 2018 10:52:50 -0800, sms
wrote:


[...]


It's a 2 cell 18650 pack with the batteries in parallel, and a
protection circuit board shared between the two cells. The cells are
allegedly 2800mAH, for a total of 5600mAH.


Seems rather high.



Probably a Chinese spec :-)

Just like with lights where there are lumens and then there are Chilumens..


... Note that batteries are tested at a 0.2C
discharge, which yields larger numbers than the usual headlight
discharge rate. The Lezyne Deca 1500XXL claims 1500 lumens, which
also seems a bit high. Assuming 120 lumens/watt at a nominal
3.7V/battery, that's:
1500 / 120 / 3.7 = 3.4A
to run the headlight at full brightness, or 1.7A per cell.
Meanwhile, the cell capacity is tested at:
0.2 * 2800 = 0.56A


Classic American answer: Then you need a bigger battery. On my road bike
I use eight 18650 cells, four in parallel and two of those packs in
series so the current on the cable to the front light doesn't exceed 1A,
at least not by much.

My MTB has to make do with four cells but except for short bursts on
city streets or fast county roads I drop that down from 8W to 3W or
sometimes even 1.5W in front.

I ride all roads in car traffic with lights, day and night, and then
usually at full bore. Bike paths sans DRL, singletrack with just the
front light lit so dirt bikers see me.


Get a low-watt blinker for daytime if you need a DRL. It's more conspicuous than a fixed beam, depending on where you are riding. I only use a DRL during morning hours, rainstorms or overcast (sometimes). I use a little Nashbar flasher, which is pretty average for riders around here. My rain gear is high-viz, and I tend to avoid all-black like some of my more fashionable cohorts. In daylight, I see rider jerseys long before lights except under rare circumstances.

I'm about to ride home, and if (after climbing out of the parking garage) I decide to ride home on the frustrating cycle path, I will encounter endless dopes with 1000 lumen lights pointed straight at me. Oddly, because of the alignment of the cycletrack, I will not be able to determine whether they are on-coming bicycles in the side-by-side two-way bike lane or cars out on the road. The brighter the light, the more it will look like a car -- and not a bike that will pass me within five inches. One day, I will have a head-on if I ride that path enough.

A beam with cut-off and lower intensity would be much more noticeable as a bike and would not blind me. A 1 watt flasher would make it even more recognizable. One can justify a bright, less-shaped light away from other riders, but blasting the retina burners around other cyclists is unconscionable.

-- Jay Beattie.



  #66  
Old February 10th 18, 06:26 AM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,746
Default Battery Replacement on Lights with Internal Li-Ion Batteries

On Fri, 9 Feb 2018 13:35:24 -0800, sms
wrote:

On the light with the new 5200mAH battery back, one test gave 157
minutes, one 162 minutes.

On the light with the old 5600mAH battery pack, one test gave 193
minutes, one test gave 216 minutes.


It would seem that your new Amazon batteries are somewhat over-rated
and that your old battery pack still has quite a bit of life left.

Let's see what the numbers show:

1400 lumens, at an optimistic 150 lumens/watt equals 9.3 watts.
At a nominal 3.7V battery voltage, current drain:
9.3w / 3.7v = 2.5A

The rated 5600 ma-hr is measured at 0.2C. At roughly 1 C the rating
drops by approximately 15% to 4800 ma-hr.
4800mA-hr / 2500mA = 1.9 hrs = 115 minutes

You're doing much better than I would predict.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #67  
Old February 10th 18, 08:01 AM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 221
Default Battery Replacement on Lights with Internal Li-Ion Batteries

On Friday, February 9, 2018 at 10:35:27 PM UTC+1, sms wrote:
On 2/8/2018 12:21 PM, Joerg wrote:
On 2018-02-06 20:48, Jeff Liebermann wrote:
On Tue, 6 Feb 2018 10:52:50 -0800, sms
wrote:


[...]


It's a 2 cell 18650 pack with the batteries in parallel, and a
protection circuit board shared between the two cells. The cells are
allegedly 2800mAH, for a total of 5600mAH.

Seems rather high.



Probably a Chinese spec :-)

Just like with lights where there are lumens and then there are Chilumens.


**************** ... Note that batteries are tested at a 0.2C
discharge, which yields larger numbers than the usual headlight
discharge rate.* The Lezyne Deca 1500XXL claims 1500 lumens, which
also seems a bit high.* Assuming 120 lumens/watt at a nominal
3.7V/battery, that's:
*** 1500 / 120 / 3.7 = 3.4A
to run the headlight at full brightness, or 1.7A per cell.
Meanwhile, the cell capacity is tested at:
*** 0.2 * 2800 = 0.56A


Classic American answer: Then you need a bigger battery. On my road bike
I use eight 18650 cells, four in parallel and two of those packs in
series so the current on the cable to the front light doesn't exceed 1A,
at least not by much.


I decided to do run-time tests on my two Lezyne Decadrive 1500xxl lights.

I think that I have never before experienced a light manufacturer that
significantly under-stated run times.

Running both in "Overdrive Race Mode" the run time was much higher than
the manual stated. mtbr.com measured "Overdrive Race Mode" at 1390
lumens, a little less than the claimed 1500 lumens. The manual says 100
minutes in "Overdrive Race Mode."

On the light with the new 5200mAH battery back, one test gave 157
minutes, one 162 minutes.

On the light with the old 5600mAH battery pack, one test gave 193
minutes, one test gave 216 minutes.

I did not run the battery all the way down. When the "10% remaining"
indicator occurred I stopped the test.

I am going to do a third test as well, as soon as the batteries are
recharged.


Did you also measured the light output over time? Otherwise the numbers mean nothing to me.

Lou
  #68  
Old February 10th 18, 11:41 AM posted to rec.bicycles.tech
Oculus Lights[_2_]
external usenet poster
 
Posts: 27
Default Battery Replacement on Lights with Internal Li-Ion Batteries

On Saturday, February 10, 2018 at 12:01:17 AM UTC-8, wrote:
On Friday, February 9, 2018 at 10:35:27 PM UTC+1, sms wrote:
On 2/8/2018 12:21 PM, Joerg wrote:
On 2018-02-06 20:48, Jeff Liebermann wrote:
On Tue, 6 Feb 2018 10:52:50 -0800, sms
wrote:


[...]


It's a 2 cell 18650 pack with the batteries in parallel, and a
protection circuit board shared between the two cells. The cells are
allegedly 2800mAH, for a total of 5600mAH.

Seems rather high.


Probably a Chinese spec :-)

Just like with lights where there are lumens and then there are Chilumens.


**************** ... Note that batteries are tested at a 0.2C
discharge, which yields larger numbers than the usual headlight
discharge rate.* The Lezyne Deca 1500XXL claims 1500 lumens, which
also seems a bit high.* Assuming 120 lumens/watt at a nominal
3.7V/battery, that's:
*** 1500 / 120 / 3.7 = 3.4A
to run the headlight at full brightness, or 1.7A per cell.
Meanwhile, the cell capacity is tested at:
*** 0.2 * 2800 = 0.56A


Classic American answer: Then you need a bigger battery. On my road bike
I use eight 18650 cells, four in parallel and two of those packs in
series so the current on the cable to the front light doesn't exceed 1A,
at least not by much.


I decided to do run-time tests on my two Lezyne Decadrive 1500xxl lights.

I think that I have never before experienced a light manufacturer that
significantly under-stated run times.

Running both in "Overdrive Race Mode" the run time was much higher than
the manual stated. mtbr.com measured "Overdrive Race Mode" at 1390
lumens, a little less than the claimed 1500 lumens. The manual says 100
minutes in "Overdrive Race Mode."

On the light with the new 5200mAH battery back, one test gave 157
minutes, one 162 minutes.

On the light with the old 5600mAH battery pack, one test gave 193
minutes, one test gave 216 minutes.

I did not run the battery all the way down. When the "10% remaining"
indicator occurred I stopped the test.

I am going to do a third test as well, as soon as the batteries are
recharged.


Did you also measured the light output over time? Otherwise the numbers mean nothing to me.

Lou


my Oculus lights have a field replaceable battery design. Np changing batteries when drained and replacing with a freshly charged battery, if you aren't able to plug the charger into the charging jack. Your choice of high capacity 5500mAH 26650 or 3500mAH Panasonic 18650.
  #69  
Old February 10th 18, 08:27 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 5,107
Default Battery Replacement on Lights with Internal Li-Ion Batteries

On 2018-02-08 16:50, Frank Krygowski wrote:
On Thursday, February 8, 2018 at 7:24:58 PM UTC-5, Joerg wrote:
On 2018-02-08 16:01, Frank Krygowski wrote:
On Thursday, February 8, 2018 at 4:14:47 PM UTC-5, Joerg wrote:
On 2018-02-08 12:20, AMuzi wrote:
On 2/8/2018 2:08 PM, Joerg wrote:


Those 2.4W bulbs were a joke. My bikes (after my teenage
years) always had better lighting than that. Now it's all
LED on my bikes but the real stuff with more than 500 lumens.


For years with a Margil cover or, after a Krygowski mod with O ring, and
without a switch (always on) I have no complaints about function or
longevity. YMMV.


How much does that O-ring reduce the drag? In the old days (with a real
power bus on the bike) I often rode the first miles with the dynamo off
because of the drag. I only put it back to the wheel when the "steam
gauge needle" (remember those?) got too close to the red range.

First, the terrors of dyno drag are mostly a myth. This article deals with it:
http://www.myra-simon.com/bike/dynotest.html
"the slowing down has more to do with psychology than the actual power required
to turn it."
and
"All of the generators were easier to turn than riding up a 1 in 300 slope.
Another way of putting that is a rise of 18 feet per mile; and there's quite a
cluster of sidewall and hub-driven models around the 1/500 line, or 10 ft per
mile."


Well, take another look at your link. I routinely ride at 30km/h at
which bottle dynamos waste 15W or more. That is nothing to sneeze at.


You seem to not understand the math. Is 15W nothing to sneeze at? It's the same
as climbing 18 feet in a mile.

I've related this before, but: On one solo tour, I was riding west on a deserted
flat four-lane concrete highway. I had four panniers and full camping gear, but
I was riding very well at a very consistent 20 mph.

Then I hit a bad expansion joint. It really jolted me. Worse, I heard some sort
of weird whirring noise, barely audible. And I noticed my speed had dropped
to about 19 miles per hour. Ideas like a dragging brake or a fender scraping
ran through my mind, but I could see nothing wrong.

Then I realized my bottom bracket dynamo had snapped on because of the jolt.
It was a near-perfect test of dynamo drag. Riding with it on cost me one mile
per hour. Big deal!


If you are willing to give up 1mph this easy, fine. I am not and I have
found a much better solution.


I find it odd that a guy routinely tells us weight doesn't matter to him, but is
afraid of dyno drag equivalent to riding a 1 in 300 slope.


Hint: In the flatlands and with a nice high tire pressure weight doesn't
make much of a difference.


So is that the only place you ride?? You give the impression of oh-so-gnarly
riding. Once again, your song changes wildly depending on your argument.


If you had followed more carefully you'd have know that there are two
places I ride a lot: Here in the hills and then down in the Sacramento
Valley. As I wrote many times that valley is huge and very flat. Nearly
all errand rides have to head in that direction because that's where
nearly all stores are.


Regarding the O-ring solution - that is, cutting a groove in the dyno drive
wheel, snapping in a suitable O-ring and running that on the rim sidewall
instead of the tire - it makes the dyno almost silent. That should greatly
reduce your psychological stress, Joerg, but it probably reduces the drag a bit,
too. The deformation and scrubbing of the contact patch between the tire and
the dyno's roller is responsible for a significant portion of dyno drag. I think
the O-ring has a lot less scrubbing and a lot less hysteresis loss.


Yeah, I should give that a try. Still got a dynamo on the road bike from
the days when I had NiCd batteries which didn't have the capacity of
Li-Ion. Only issue is, it's a Soubitez dynamo where the wheel is not
removable. I'd have to figure a way to grab it at its outside diameter
with a hose or something and then drive that hose with a power drill at
a speed the dynamo can stomach for a while, then hold the corner of a
file to it.


Regarding the "speed the dynamo can stomach for a while": At 15 mph, your wheel
rotates about 180 rpm. The much smaller drive wheel on a sidewall dyno spins
about 4500 rpm or more. Your electric drill won't hurt it.


Thanks. Then it should be possible, maybe even without removing the dynamo.


I just chucked mine in my lathe. If you don't have a lathe, perhaps try using
a drill press if its chuck is large enough. But I did remove the drive wheel
first.


On my dynamo it isn't removable. A (very small) lathe is on my bucket
list. Probably one of those PC-controlled XYZ tables.


Also, my last front Gatorskin is still on there and those have
paper-thin sidewalls. I'd have to mount another tire.


The point is to run the O-ring on the rim's braking surface.


Aha, that makes sense. Thanks.

--
Regards, Joerg

http://www.analogconsultants.com/
  #70  
Old February 10th 18, 08:30 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 5,107
Default Battery Replacement on Lights with Internal Li-Ion Batteries

On 2018-02-09 11:40, Ian Field wrote:


"Joerg" wrote in message
...
On 2018-02-08 16:01, Frank Krygowski wrote:
On Thursday, February 8, 2018 at 4:14:47 PM UTC-5, Joerg wrote:
On 2018-02-08 12:20, AMuzi wrote:
On 2/8/2018 2:08 PM, Joerg wrote:


Those 2.4W bulbs were a joke. My bikes (after my teenage
years) always had better lighting than that. Now it's all
LED on my bikes but the real stuff with more than 500 lumens.


For years with a Margil cover or, after a Krygowski mod with O
ring, and
without a switch (always on) I have no complaints about function or
longevity. YMMV.


How much does that O-ring reduce the drag? In the old days (with a real
power bus on the bike) I often rode the first miles with the dynamo off
because of the drag. I only put it back to the wheel when the "steam
gauge needle" (remember those?) got too close to the red range.

First, the terrors of dyno drag are mostly a myth. This article deals
with it:
http://www.myra-simon.com/bike/dynotest.html
"the slowing down has more to do with psychology than the actual
power required
to turn it."
and
"All of the generators were easier to turn than riding up a 1 in 300
slope.
Another way of putting that is a rise of 18 feet per mile; and
there's quite a
cluster of sidewall and hub-driven models around the 1/500 line, or
10 ft per
mile."


Well, take another look at your link. I routinely ride at 30km/h at
which bottle dynamos waste 15W or more. That is nothing to sneeze at.


Bottle dynamos also tend to slip if wet or muddy.



On my MTB it wold be quite useless. On the road bike I could use in just
while not slippery. It has a large battery so 4h no-charge wouldn't be a
problem.

--
Regards, Joerg

http://www.analogconsultants.com/
 




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