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#61
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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 Looks like what I was told was either wrong or out of date - but I have been warned that a backup battery may not make a dynamo ant less illegal. |
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#62
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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. Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* ... Note that batteries are tested at a 0.2C discharge, which yields larger numbers than the usual headlight discharge rate.Â* The Lezyne Deca 1500XXL claims 1500 lumens, which also seems a bit high.Â* Assuming 120 lumens/watt at a nominal 3.7V/battery, that's: Â*Â*Â* 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: Â*Â*Â* 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
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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
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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
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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
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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
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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. Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* ... Note that batteries are tested at a 0.2C discharge, which yields larger numbers than the usual headlight discharge rate.Â* The Lezyne Deca 1500XXL claims 1500 lumens, which also seems a bit high.Â* Assuming 120 lumens/watt at a nominal 3.7V/battery, that's: Â*Â*Â* 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: Â*Â*Â* 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
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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. Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* ... Note that batteries are tested at a 0.2C discharge, which yields larger numbers than the usual headlight discharge rate.Â* The Lezyne Deca 1500XXL claims 1500 lumens, which also seems a bit high.Â* Assuming 120 lumens/watt at a nominal 3.7V/battery, that's: Â*Â*Â* 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: Â*Â*Â* 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
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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
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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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