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#121
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Battery Replacement on Lights with Internal Li-Ion Batteries
On 2/12/2018 9:23 AM, Joerg wrote:
On 2018-02-12 08:51, sms wrote: On 2/12/2018 8:03 AM, Joerg wrote: snip Simple: When clicking the light on you must stand over it or near it. It could, for example, issue three short flashes after turn-on for batt-ok, two flashes for "enough but not for more than a few hours" and on flash for "it'll be empty very soon". That's reasonable for a USB powered light with Li-Ion batteries. For a device running on AA or AAA batteries, not really, because different chemistry AA batteries have very different voltages and discharge curves. Battery voltage for primary D, C, AA, AAA, AAAA cells: Â*Â*Â*Â*Â* Alkaline-manganese dioxide: 1.5V. Linear voltage degradation Â*Â*Â*Â*Â* NiMH: 1.2V with almost do voltage degradation until fully discharged. Â*Â*Â*Â*Â* Primary Lithium (LiFeS2): up to 1.83V, typically 1.7V, discharged if 1.6V or less. Decreasing voltage during discharge, not quite linear. I have seen a device where there was a switch to flip for NiMH versus Alkaline to account for the different voltages in order to provide a more accurate low battery warning, though no option for LiFeS2. You could provide a zero-cost alkaline-NiMH function swap by, for example, pressing the on-off button for 3sec. Not necessary though because more rear lights are a bit dim with 1.2V NiMH and I bet 99% of riders use AAA cells. So just provide a lo-bat warning for alkaline and that goes a long way. Of course, for that to work the IC designers must be competent enough to include a decent bandgap reference. You wouldn't believe how many aren't. It doesn't have to be accurate, just ballpark. Mainly because almost nobody remembers how many hours the recent set of batteries has been used. Another near-zero cost method would be to provide a coarse timer. 5h-10-15h-20h-25h. Simple RC or relaxation oscillator, one through five flashes for status, done. Or just count the number of blinks. Serious riders know how long batteries of their choice will last so they can then decide at 15h or 20h to change them out. Product design can be quite simple and cheap if we just think outside the box and most of all try the designed products ourselves. A bike accessory manufacturer should preferably hire ... riders. Yes, but they need to hire riders that aren't geeks if they want to design something usable. To do low-battery right on a light where you don't know what type of batteries will be used, you can't do correlation, you need an optical solution, like an opto-isolator inside that tracks the light output of the LEDs and indicates when intensity is falling, independent of battery type. For internal rechargeable Li-Ion batteries it's easy to roughly correlate voltage with remaining capacity. And seriously, while geeks may count blinks and program the battery type via button presses, not everyone that bicycles is an engineer. It's hard enough to explain how to cycle through the different modes. The battery indicator on my Lezyne is simple and perfect. Green 50%. Yellow =11-50%. Red 10% or less. I don't need a bar graph LCD or a digital readout. I saw "the perfect light" at one Interbike because you could program the modes including intensity and flash rate via button presses. Since many lights keep the DRL flasher at full intensity, which is unnecessary, I thought that this was a good idea. But it was way too complex for the normal rider. A software person would get frustrated and dump their herbal tea onto the light. |
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#122
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Battery Replacement on Lights with Internal Li-Ion Batteries
On 2/12/2018 9:42 AM, Joerg wrote:
On 2018-02-12 07:56, sms wrote: The key to getting more people out on bicycles is to promote equipment that allows them to ride to work or school in normal clothes, and provide routes that make the ride practical. Amen! Many people do not understand this and that includes a lot here in the NG. Because it is mostly enthusiasts in the NG. We need to understand how normal people think sic. A bicycle boulevard without a bicycle lane? What is a bicycle boulevard then? It is heavily traffic-calmed. There are few stop signs (stop signs are on the cross streets. It is well marked. It goes all the way from outlying residential neighborhoods to schools and to downtown. It is very heavily used. Some people think that bicycle lanes are the only infrastructure that will get people onto bikes for transportational cycling but that's not true. People will ride on quiet streets as well. The bicycle boulevards aren't suitable for fast recreational rides. You're not going to find many riders going faster than 15 MPH (unless they're on an electric bicycle). scratching head Those three others are unfortunately typical, sounds like our village :-( The others were not bad people (well not all of them) they just were not interested in cycling, except in theory. I am pretty lucky that right now we have four out of five council people that are pretty supportive of bicycling, even if we disagree on other major issues. We have a chance to make that five out of five this November. I have been trying to get a bicycle light giveaway going, even though most riders could afford lights they don't get them. Especially bad is students riding to school in the early morning when it's dark. Won't help much. I dread going through Davis with my car but sometimes had to because of carrying a heavy load. At night cyclists dart around willy-nilly. Traffic rules? Red lights? Phhht, that ain't meanin' nuthin'. Many have rear lights and they are mostly either off or are very dim and have depleted alkalines in them that have been leaking for weeks. I think that the key is USB rechargeable. People have become accustomed to plugging in their devices at night, phones, tablets, cars, laptops, etc.. |
#123
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Battery Replacement on Lights with Internal Li-Ion Batteries
On 2018-02-12 10:45, sms wrote:
On 2/12/2018 9:42 AM, Joerg wrote: On 2018-02-12 07:56, sms wrote: The key to getting more people out on bicycles is to promote equipment that allows them to ride to work or school in normal clothes, and provide routes that make the ride practical. Amen! Many people do not understand this and that includes a lot here in the NG. Because it is mostly enthusiasts in the NG. We need to understand how normal people think sic. If we want to foster cycling in general then we sure have to. And soon because just a few years from now almost everyone interested in cycling will lean towards electric bikes. Which are essentially a mopeds without the stench. A bicycle boulevard without a bicycle lane? What is a bicycle boulevard then? It is heavily traffic-calmed. There are few stop signs (stop signs are on the cross streets. It is well marked. It goes all the way from outlying residential neighborhoods to schools and to downtown. It is very heavily used. Some people think that bicycle lanes are the only infrastructure that will get people onto bikes for transportational cycling but that's not true. People will ride on quiet streets as well. Yes, they generally will. The bicycle boulevards aren't suitable for fast recreational rides. You're not going to find many riders going faster than 15 MPH (unless they're on an electric bicycle). That's ok as long as you can go faster without endangering others. When I am down in the flatlands the speedometer is usually between 17mph and 19mph. scratching head Those three others are unfortunately typical, sounds like our village :-( The others were not bad people (well not all of them) they just were not interested in cycling, except in theory. I am pretty lucky that right now we have four out of five council people that are pretty supportive of bicycling, even if we disagree on other major issues. We have a chance to make that five out of five this November. Keeping my fingers crossed. I have been trying to get a bicycle light giveaway going, even though most riders could afford lights they don't get them. Especially bad is students riding to school in the early morning when it's dark. Won't help much. I dread going through Davis with my car but sometimes had to because of carrying a heavy load. At night cyclists dart around willy-nilly. Traffic rules? Red lights? Phhht, that ain't meanin' nuthin'. Many have rear lights and they are mostly either off or are very dim and have depleted alkalines in them that have been leaking for weeks. I think that the key is USB rechargeable. People have become accustomed to plugging in their devices at night, phones, tablets, cars, laptops, etc.. Having to detach the light every night is cumbersome. If it can be charged while mounted that would be ok. That is what I do right now for the large central batteries on the road bike and the MTB except it's a coaxial-style connector. When I get home I plug in the bike. It's part of the routine just like it is with owners of electric vehicles. Would be nice if all electricity is concentrated in one place though so you don't have to run several cables per bike (I have multiple rear lights and a bike-mounted MP3 player). Removable lights are impractical in another sense as well. You can't park the bike unattended without dataching and schlepping all that stuff. Else you might come back to a safely locked bike but all those accessories are gone. That's real fun at night. Regarding those 18650 battery packs I have to say that is one of the (very few) areas where bicycles can outshine cars. I just had my 2nd car battery fail within the warranty period but the bike batteries keep going like the Energizer bunny. Ok, they are modern Li-Ion technology while the cars have ye olde lead-acid batteries. -- Regards, Joerg http://www.analogconsultants.com/ |
#124
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Battery Replacement on Lights with Internal Li-Ion Batteries
On Monday, February 12, 2018 at 10:45:37 AM UTC-8, sms wrote:
On 2/12/2018 9:42 AM, Joerg wrote: On 2018-02-12 07:56, sms wrote: The key to getting more people out on bicycles is to promote equipment that allows them to ride to work or school in normal clothes, and provide routes that make the ride practical. Amen! Many people do not understand this and that includes a lot here in the NG. Because it is mostly enthusiasts in the NG. We need to understand how normal people think sic. This place is crawling with normal people on bikes, particularly on a dry day. I was totally miserable in bike traffic this morning. I don't think any of the normal people I rode with this morning had DRLs -- maybe a few. I wasn't paying attention. Most of the normal people I ride with would laugh at needing a 1000 lumen light to ride in broad daylight -- or any light. It's the serious, non-normal cyclists who are convinced they need special DRLs. Look for DRLS: https://bikeportland.org/2011/06/22/...r-photos-55300 I think I saw some blinkies. https://bikeportland.org/2013/05/06/...e-design-86376 -- one guy in a safety vest. What gets these people on bikes is sunshine, a Bohemian culture, some on-street bike lanes and close-in neighborhoods. Maybe traffic calming on some of the bike boulevards, but people were using those before they were designated boulevards. -- Jay Beattie. |
#125
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Battery Replacement on Lights with Internal Li-Ion Batteries
On 2018-02-12 10:33, sms wrote:
On 2/12/2018 9:23 AM, Joerg wrote: On 2018-02-12 08:51, sms wrote: On 2/12/2018 8:03 AM, Joerg wrote: snip Simple: When clicking the light on you must stand over it or near it. It could, for example, issue three short flashes after turn-on for batt-ok, two flashes for "enough but not for more than a few hours" and on flash for "it'll be empty very soon". That's reasonable for a USB powered light with Li-Ion batteries. For a device running on AA or AAA batteries, not really, because different chemistry AA batteries have very different voltages and discharge curves. Battery voltage for primary D, C, AA, AAA, AAAA cells: Alkaline-manganese dioxide: 1.5V. Linear voltage degradation NiMH: 1.2V with almost do voltage degradation until fully discharged. Primary Lithium (LiFeS2): up to 1.83V, typically 1.7V, discharged if 1.6V or less. Decreasing voltage during discharge, not quite linear. I have seen a device where there was a switch to flip for NiMH versus Alkaline to account for the different voltages in order to provide a more accurate low battery warning, though no option for LiFeS2. You could provide a zero-cost alkaline-NiMH function swap by, for example, pressing the on-off button for 3sec. Not necessary though because more rear lights are a bit dim with 1.2V NiMH and I bet 99% of riders use AAA cells. So just provide a lo-bat warning for alkaline and that goes a long way. Of course, for that to work the IC designers must be competent enough to include a decent bandgap reference. You wouldn't believe how many aren't. It doesn't have to be accurate, just ballpark. Mainly because almost nobody remembers how many hours the recent set of batteries has been used. Another near-zero cost method would be to provide a coarse timer. 5h-10-15h-20h-25h. Simple RC or relaxation oscillator, one through five flashes for status, done. Or just count the number of blinks. Serious riders know how long batteries of their choice will last so they can then decide at 15h or 20h to change them out. Product design can be quite simple and cheap if we just think outside the box and most of all try the designed products ourselves. A bike accessory manufacturer should preferably hire ... riders. Yes, but they need to hire riders that aren't geeks if they want to design something usable. Ideally they should be commuting MTB riders. That guarantees a thorough quality test when these guys go offroad. My MTB has a top load platform that rides an inch above the panniers. Normally there is a trunk affixed to it but I can take that off and strap a customer prototype to it, pump the rear shock to a punishing 230psi and take the bike on a gnarly singletrack. To do low-battery right on a light where you don't know what type of batteries will be used, you can't do correlation, you need an optical solution, like an opto-isolator inside that tracks the light output of the LEDs and indicates when intensity is falling, independent of battery type. For internal rechargeable Li-Ion batteries it's easy to roughly correlate voltage with remaining capacity. And seriously, while geeks may count blinks and program the battery type via button presses, not everyone that bicycles is an engineer. It's hard enough to explain how to cycle through the different modes. Cyclists don't have to use it, they can also just turn it on and ignore the indicator flashes. The battery indicator on my Lezyne is simple and perfect. Green 50%. Yellow =11-50%. Red 10% or less. I don't need a bar graph LCD or a digital readout. That's good. Unfortunately adds cost and that's a problem for the cheapo crowd. I saw "the perfect light" at one Interbike because you could program the modes including intensity and flash rate via button presses. Since many lights keep the DRL flasher at full intensity, which is unnecessary, I thought that this was a good idea. But it was way too complex for the normal rider. A software person would get frustrated and dump their herbal tea onto the light. My rear flashing lights only have one itensity, full. Good enough. -- Regards, Joerg http://www.analogconsultants.com/ |
#126
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Battery Replacement on Lights with Internal Li-Ion Batteries
On Mon, 12 Feb 2018 07:52:45 -0800 (PST), Frank Krygowski
wrote: On Monday, February 12, 2018 at 8:25:55 AM UTC-5, sms wrote: On 2/12/2018 5:00 AM, Sepp Ruf wrote: No, Joerg is claiming that ordinary StVZO tail lights that are visible from 500 meters in Europe are not good enough for his and fellow Californians' impaired sense of vision, and why he feels tail lights that feature 5000 ft+ visibility are preferable. And he is trying to confuse what can actually be powered by dynamo with what he "remembers" seeing, back then, on inspecified cycles in traffic. The StVZO lights are woefully inadequate. Don't forget that you need one that is visible in the daytime as well. You need a daytime taillight exactly as much as you need a tall flippy flag. In fact, the flippy flag is more visible under many circumstances. Here you go: http://www.parkerflags.com/Bicycle-Flags-Prodlist.html You can't be too safe! - Frank Krygowski Some interesting statistics. Thailand passed a law some years ago that all motorcycles must have their lights on when being operated. Day or night, the normal front and rear lights must be on when the vehicle is moving. The results: These lighted vehicles are now involved in 73% of all highway accidents, in fact these lighted vehicles now account for more accidents then all other vehicles combined. Amazing how lights can make you safe in one hemisphere while (apparently) doing little or nothing to make you safe in another. Interestingly, bicycles, although bright lights are rarely seen, make up about 2% of highway accidents in Thailand. about the same as in the U.S. -- Cheers, John B. |
#127
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Battery Replacement on Lights with Internal Li-Ion Batteries
On 12/02/18 14:25, sms wrote:
On 2/12/2018 5:00 AM, Sepp Ruf wrote: No, Joerg is claiming that ordinary StVZO tail lights that are visible from 500 meters in Europe are not good enough for his and fellow Californians' impaired sense of vision, and why he feels tail lights that feature 5000 ft+ visibility are preferable.* And he is trying to confuse what can actually be powered by dynamo with what he "remembers" seeing, back then, on inspecified cycles in traffic. The StVZO lights are woefully inadequate. Don't forget that you need one that is visible in the daytime as well. You don't need a 1500 lumen tail light, but many are ridiculously weak, 10 lumens, or even less. One that looks reasonable is https://www.lezyne.com/product-led-sport-laserdrive.php with flash modes up to 250 lumens for daytime flash mode. But I don't see a way to mount it to a rear rack. Personally I would not be bolting lasers to the rear of my bile when for various reasons they may shine in peoples eyes. Must say https://www.lezyne.com/product-led-s...p#.WoKA3q3AL0o Looks quite handy for one of my bikes that doesn't have a dynamo. Decent run time at 15 lumens. |
#128
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Battery Replacement on Lights with Internal Li-Ion Batteries
John B. wrote:
On Mon, 12 Feb 2018 07:52:45 -0800 (PST), Frank Krygowski wrote: On Monday, February 12, 2018 at 8:25:55 AM UTC-5, sms wrote: On 2/12/2018 5:00 AM, Sepp Ruf wrote: No, Joerg is claiming that ordinary StVZO tail lights that are visible from 500 meters in Europe are not good enough for his and fellow Californians' impaired sense of vision, and why he feels tail lights that feature 5000 ft+ visibility are preferable. And he is trying to confuse what can actually be powered by dynamo with what he "remembers" seeing, back then, on inspecified cycles in traffic. The StVZO lights are woefully inadequate. Don't forget that you need one that is visible in the daytime as well. You need a daytime taillight exactly as much as you need a tall flippy flag. In fact, the flippy flag is more visible under many circumstances. Here you go: http://www.parkerflags.com/Bicycle-Flags-Prodlist.html You can't be too safe! - Frank Krygowski Some interesting statistics. Thailand passed a law some years ago that all motorcycles must have their lights on when being operated. Day or night, the normal front and rear lights must be on when the vehicle is moving. The results: These lighted vehicles are now involved in 73% of all highway accidents, in fact these lighted vehicles now account for more accidents then all other vehicles combined. Amazing how lights can make you safe in one hemisphere while (apparently) doing little or nothing to make you safe in another. Interestingly, bicycles, although bright lights are rarely seen, make up about 2% of highway accidents in Thailand. about the same as in the U.S. -- Cheers, John B. So what was the accident rate for motorcycles before? 50%? 90%? One number doesn't give a lot of insight here. |
#129
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Battery Replacement on Lights with Internal Li-Ion Batteries
On 2/13/2018 5:23 AM, Ralph Barone wrote:
John B. wrote: On Mon, 12 Feb 2018 07:52:45 -0800 (PST), Frank Krygowski wrote: On Monday, February 12, 2018 at 8:25:55 AM UTC-5, sms wrote: On 2/12/2018 5:00 AM, Sepp Ruf wrote: No, Joerg is claiming that ordinary StVZO tail lights that are visible from 500 meters in Europe are not good enough for his and fellow Californians' impaired sense of vision, and why he feels tail lights that feature 5000 ft+ visibility are preferable. And he is trying to confuse what can actually be powered by dynamo with what he "remembers" seeing, back then, on inspecified cycles in traffic. The StVZO lights are woefully inadequate. Don't forget that you need one that is visible in the daytime as well. You need a daytime taillight exactly as much as you need a tall flippy flag. In fact, the flippy flag is more visible under many circumstances. Here you go: http://www.parkerflags.com/Bicycle-Flags-Prodlist.html You can't be too safe! - Frank Krygowski Some interesting statistics. Thailand passed a law some years ago that all motorcycles must have their lights on when being operated. Day or night, the normal front and rear lights must be on when the vehicle is moving. The results: These lighted vehicles are now involved in 73% of all highway accidents, in fact these lighted vehicles now account for more accidents then all other vehicles combined. Amazing how lights can make you safe in one hemisphere while (apparently) doing little or nothing to make you safe in another. Interestingly, bicycles, although bright lights are rarely seen, make up about 2% of highway accidents in Thailand. about the same as in the U.S. -- Cheers, John B. So what was the accident rate for motorcycles before? 50%? 90%? One number doesn't give a lot of insight here. LOL, exactly the right question. Also, what else changed besides the lighting requirement? Some people don't WANT to understand the difference between correlation and causation! |
#130
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Battery Replacement on Lights with Internal Li-Ion Batteries
On Tuesday, February 13, 2018 at 10:54:32 AM UTC-8, sms wrote:
On 2/13/2018 5:23 AM, Ralph Barone wrote: John B. wrote: On Mon, 12 Feb 2018 07:52:45 -0800 (PST), Frank Krygowski wrote: On Monday, February 12, 2018 at 8:25:55 AM UTC-5, sms wrote: On 2/12/2018 5:00 AM, Sepp Ruf wrote: No, Joerg is claiming that ordinary StVZO tail lights that are visible from 500 meters in Europe are not good enough for his and fellow Californians' impaired sense of vision, and why he feels tail lights that feature 5000 ft+ visibility are preferable. And he is trying to confuse what can actually be powered by dynamo with what he "remembers" seeing, back then, on inspecified cycles in traffic. The StVZO lights are woefully inadequate. Don't forget that you need one that is visible in the daytime as well. You need a daytime taillight exactly as much as you need a tall flippy flag. In fact, the flippy flag is more visible under many circumstances. Here you go: http://www.parkerflags.com/Bicycle-Flags-Prodlist.html You can't be too safe! - Frank Krygowski Some interesting statistics. Thailand passed a law some years ago that all motorcycles must have their lights on when being operated. Day or night, the normal front and rear lights must be on when the vehicle is moving. The results: These lighted vehicles are now involved in 73% of all highway accidents, in fact these lighted vehicles now account for more accidents then all other vehicles combined. Amazing how lights can make you safe in one hemisphere while (apparently) doing little or nothing to make you safe in another. Interestingly, bicycles, although bright lights are rarely seen, make up about 2% of highway accidents in Thailand. about the same as in the U.S. -- Cheers, John B. So what was the accident rate for motorcycles before? 50%? 90%? One number doesn't give a lot of insight here. LOL, exactly the right question. Also, what else changed besides the lighting requirement? Some people don't WANT to understand the difference between correlation and causation! When it comes to DRLs, correlation is about all we have. I haven't seen a single study where are driver claimed he or she saw a bicyclist and avoided an accident during daylight hours because of a light. Jackets seem to be scoring well: https://www.sciencedirect.com/scienc...25753517313528 Here's the famous DRL study: https://www.sciencedirect.com/scienc...01457512002606 The latter study was, of course, the famous Odense, Denmark study where the subjects used a Reellight. https://www.reelight.com/products/hu...nt=34453441105 https://www.youtube.com/watch?v=QM6E5PBKPqg Awesome! In bright daylight, that will have motorists covering their eyes to avoid being blinded! https://www.youtube.com/watch?v=FBLvQGfeXSQ Joerg, problem solved. This light even reduced "solo accidents" by 27%! Slap on one of these magnetic blinkies and eliminate one out of four gnarly-trail crashes. Remember, the face your plant is your own. -- Jay Beattie. |
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