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#21
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Black Friday Deals on Bicycle Lights
On 11/28/2016 11:09 AM, Joerg wrote:
On 2016-11-28 10:36, sms wrote: On 11/28/2016 7:59 AM, Joerg wrote: snip 1h is no problem. I found that USB re-charge is nice. My previous light has re-chargeable Li-Ion the size of 18650 but the cap can be removed and a USB plug shows up. Plugs into any contemporary computer and the light ring on the battery turns from red to yellow when fully charged. I always carried a spare though. For the Lezyne it's best to use a higher current (2.1-2.4A) USB charger. The USB ports on a computer are only guaranteed to put out 500mA, though on most computers the over-current limit is set to 1000mA. That sounds like people didn't pay attention during the design review, hoping they held at least one. My hand would have gone up immediately. In this day and age it should be no problem to provide some "secret" button-press sequence that switches the charge current from 2A to 400mA or so and keeps it latched there until further notice. Usually that's a no-cost feature except for a few engineering hours or NRE. Not at all. The USB spec has a minimum charge current as well as a maximum. USB-C can go up to 5A, hence the new Macbook Pro being charged via USB-C. There are UL/CSA/TUV reasons for limiting the current. The old AT and ATX keyboard/mouse ports had a 500mA Picofuse. Your wife would have to get two chargers or always schlepp the one back and forth. I also can't imagine repeated 2A charging being very healthy for a Li-Ion cell of 18650 or similar size. Perfectly acceptable to charge a 2800mAH 18650 at 0.7C rate which would be a little less than 2A. Some custom charging systems, like on a Tesla, charge the 18650s at a much higher rate on a Supercharger, but they have some kind of an active cooling system, and they're using 3400mAH 18650 cells in at least some of their packs. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
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#22
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Black Friday Deals on Bicycle Lights
On 2016-11-28 11:21, sms wrote:
On 11/28/2016 11:09 AM, Joerg wrote: On 2016-11-28 10:36, sms wrote: On 11/28/2016 7:59 AM, Joerg wrote: snip 1h is no problem. I found that USB re-charge is nice. My previous light has re-chargeable Li-Ion the size of 18650 but the cap can be removed and a USB plug shows up. Plugs into any contemporary computer and the light ring on the battery turns from red to yellow when fully charged. I always carried a spare though. For the Lezyne it's best to use a higher current (2.1-2.4A) USB charger. The USB ports on a computer are only guaranteed to put out 500mA, though on most computers the over-current limit is set to 1000mA. That sounds like people didn't pay attention during the design review, hoping they held at least one. My hand would have gone up immediately. In this day and age it should be no problem to provide some "secret" button-press sequence that switches the charge current from 2A to 400mA or so and keeps it latched there until further notice. Usually that's a no-cost feature except for a few engineering hours or NRE. Not at all. The USB spec has a minimum charge current as well as a maximum. USB-C can go up to 5A, hence the new Macbook Pro being charged via USB-C. There are UL/CSA/TUV reasons for limiting the current. The old AT and ATX keyboard/mouse ports had a 500mA Picofuse. The latter is just the point. I've seen cases where a supposedly resettable thermo-fuse (probably not Pico) has decided to come on for good, leaving a small patch of "scorched earth" on the circuit board and an amperage smell wafted through the air. In other case there was just a little PHUT sound and from then on that USB port no longer worked. When I design circuitry like this I never use anything thermal. It's always a real electronic solution for current limiting. Your wife would have to get two chargers or always schlepp the one back and forth. I also can't imagine repeated 2A charging being very healthy for a Li-Ion cell of 18650 or similar size. Perfectly acceptable to charge a 2800mAH 18650 at 0.7C rate which would be a little less than 2A. Aceptable from a safety point of view, yes. Battery life? Not so much: http://powerelectronics.com/portable...ttery-life.pdf Quote "Avoid high charge and discharge currents. High charge and discharge currents reduce cycle life. Some chemistries are more suited for higher currents such as Li-ion manganese and Li-ion phosphate. High currents place excessive stress on the battery". Heat is the enemy of most rechargeable batteries. Fast chargers employ cooling or at least temperature sensing. ... Some custom charging systems, like on a Tesla, charge the 18650s at a much higher rate on a Supercharger, but they have some kind of an active cooling system, and they're using 3400mAH 18650 cells in at least some of their packs. That is a well dialed-in system with cooling and whatnot. Very different ballgame. I am using slow-charge on my old cell phone and after about 10 years it is still on the first battery and no discernible loss in uptime per charge. Same on the bicycle batteries which are 4400mAh on the MTB and 8800mAh on the road bike (will be swapped soon). Those get charge at about 1A. If I'd be a bicycle messenger I'd have a souped-up hub dynamo for charging. SEPIC switcher and maybe an MPPT algorithm, plus probably a downhill switch. -- Regards, Joerg http://www.analogconsultants.com/ |
#23
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Black Friday Deals on Bicycle Lights
On Mon, 28 Nov 2016 10:52:38 -0800, sms
wrote: On 11/28/2016 10:48 AM, Jeff Liebermann wrote: Incidentally, I gave up on battery powered soldering irons long ago. They don't get hot enough for what I normally solder. I had the Wahl Isotip. But with lead-free solder you need a hotter iron. This Dremel butane model is pretty good: http://www.frys.com/product/8871752. I have a similar model that I use when soldering on top of a radio tower. The slightest breeze instantly cools the tip. Butane works nicely, as long as the copper tip is reasonably massive. Also, I've done a few Makita cordless drill conversions from NiCd/NiMH to LiIon batteries. The battery packs are small enough to fit inside the battery compartment (with foam spacers). The LiIon battery is charged externally, using an RC style balance charger. 18v systems works best because that's exactly 5 LiIon cells. 12v is a problem, but works acceptably with 4 cells (14.4v). Li-Ion is supposed to be charged with 4.2V per cell to charge to 3.7V per cell. We have a device at work with 3 cells and a 12V charger works, but I can't imagine doing 4 cells with a 12V charger. Lithium-ion almost immediately drops in voltage after the initial charge. It starts at 4.2v and is down to about 3.9v fairly quickly. It then spends most of its life between 3.9v and 3.6v. 4 cells at 3.9v = 15.6v. This is well above the nominal battery voltage for NiCd or NiMh. However, the Makita drill motors seem to handle it nicely and I like the extra power. The drills would have ended up as eWaste because of the high cost of replacement batteries and the tendency for the stock chargers to kill batteries. I currently considering a 9.6v Makita battery upgrade. I'm undecided if I should go with 2 cells (7.2v) or 3 cells (10.8v). Probably the higher voltage. Also, I don't use the stock Makita charger with my replacement LiIon battery packs. I use XT60 RC power connectors, 4S balance charger connector, to an iMax B6 balance charger: https://hobbyking.com/en_us/imax-b6-50w-5a-charger-discharger-1-6-cells-genuine.html A pull string allows the battery to be easily removed and replaced with a charged battery. I'm a little worried about shorts as I'm using unprotected cells and do not have a BMS (battery managment system). -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#24
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Black Friday Deals on Bicycle Lights
On 2016-11-27 21:20, Sir Ridesalot wrote:
On Sunday, November 27, 2016 at 9:52:34 PM UTC-5, Jeff Liebermann wrote: On Sun, 27 Nov 2016 17:52:27 -0800 (PST), DATAKOLL MARINE RESEARCH wrote: need James or Lieb explain if the proprietary battery is X more effective in a designed for system or if this idea avoids the obvious that the prop like most props yields more $$$ A non-removable battery solves a few problem and is most certainly cheaper than a removable battery. By making it non-removable, the following parts disappear: 1. Battery holder with springs. You can use welded tab batteries. 2. Tolerance space for odd side and swollen batteries. 3. Separation between battery compartment and PCB (printed circuit board). 4. Battery cover and chronically broken hinge and latch. 5. Inventory of batteries as an "accessory". 6. Claims that the light doesn't meet runtime specs because someone crammed in a low quality battery. 7. Protection circuitry for a battery inserted backwards. 8. Battery ID chip inside battery case (for counterfeit detection). 9. Battery short circuit protection and BMS (battery managment system). A non-removable battery also: 1. Allows for an internal charge controller. 2. Allows for a smaller case. 3. Allows the use of "flat" prismatic cells (similar to a smartphone) instead of cylinderical 18650 type cells. 4. Allows the use of a coulomb counter to act as a fuel gauge. 5. Whatever else I forgot. My guess(tm) is that bicycle light manufacturers will follow the lead of cell phone makers and tie their warranty to the life of the battery. If the calculated life of the battery is perhaps 5 years, the manufacturer can safely offer a 3 year warranty and be fairly certain that the battery will be mostly functional at the end of the warranty period. This eliminates the need to replace the battery during the warranty. After the warranty expires, the manufacturer or vendor could care less. It's now eWaste. That's the down side of a non-removable battery. The light could continue to be used long past the end of the warranty period, but only if the owner is willing to tear it apart and replace the battery. But, if you're NOT willing to replace the non-removable battery, you're buying what might be a limited life, throw-away product. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 A non-removable battery can not be switiched out on a very long ride in the dark. A non-removable light can lose a fair bit of charge when it's very cold outside. An external b attery pack can be tuck up under one's jacket to warm the battery and keep it runninh longer. It's what I do in winter on lond rides in the dark. Like everything, there are advantages and disadvantages that need to be considered for each person's needs or wants. IMO the best is what (as usual ...) the motor vehicle industry offers since, oh, 100 years or so. Lights plus central battery. This is what I have on both bicycles. What is still missing is a generator or dynamo but the packs are plenty large to last even long rides in the dark. I might add that to my road bike next time the front rim is up. When using standard connectors it would also be possible to swap out a pack in case the ride was way longer than planned or the rider forgot to turn off the lights at the destination. The sad part is that those packs only come in some flimsy velcro-fastened holders which flop about during rough ride, or ... fall off. On the MTB I gave it a smash-proof enclosure in which it rides fasted around rubber cushions. On the road bike it rides in the right pannier but that needs to change. Why on earth they don't offer these as a stack to be mounted inside the seat tube or fork tube I'll never understand. Tying a good rear light into the circuitry also requires some home-brewing. As usual with bicycles. -- Regards, Joerg http://www.analogconsultants.com/ |
#25
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Black Friday Deals on Bicycle Lights
Jeff Liebermann considered Mon, 28 Nov 2016
10:38:06 -0800 the perfect time to write: On Sun, 27 Nov 2016 21:20:15 -0800 (PST), Sir Ridesalot wrote: A non-removable battery can not be switiched out on a very long ride in the dark. I beg to differ. The various "soft power switch" devices I've dealt with, which lack a proper DC on/off switch, draw very little current when off or in standby. Just about every laptop is like that, with power being applied only to the switching circuitry and where the full DC power does not go through the tiny on/off push button. I think you've misunderstood - by "switched out" I believe Sir means exchanged for a fully charged battery. If the battery is not removable, you would have to either carry a spare light, or limit the length of night rides to the battery duration. A non-removable light can lose a fair bit of charge when it's very cold outside. You might be looking at it backwards. A LiIon battery has a very low self discharge rate when cold, and looses more power when warm: http://powerelectronics.com/mobile/designing-battery-packs-thermal-extremes http://powerelectronics.com/site-files/powerelectronics.com/files/archive/powerelectronics.com/images/0606batterypacks-Figure04.jpg Self discharge happens without any load, so a tiny amount of current needed to run the on/off switch doesn't even show on the graphs. What does happen is the battery looses capacity when cold: http://images.slideplayer.com/16/4877973/slides/slide_13.jpg When cold, the battery simply will not run the light as long as it would if it were warm. Actually, that's not quite right because there is no loss of available power. If you charge a battery at 25C, put it in the cooler at 0C, raise it back to 25C, and then run a discharge test, it will show the original 25C battery capacity. Nothing is "lost" when cooling the battery. Except the ability to operate at that low temperature. Once in operation, the internal temperature can be maintained simply by the battery's own chemical action (if it's fairly well insulated), but if you can't get it to START powering the light, you are stuck. Then the ability to stick the battery in your armpit for a while can be very handy, and having it permanently installed in the light makes the package bulkier and more difficult to carry in such a warm spot, as well as providing thermal insulation which means you must keep it in that warm spot for longer before the battery itself is warmed enough. An external b attery pack can be tuck up under one's jacket to warm the battery and keep it runninh longer. It's what I do in winter on lond rides in the dark. Yep, that works to improve battery capacity. Running the light cold is not a good idea, which would be a problem if the battery were non-removable. I suppose I could add a small chemical heater to the light assembly, but that would create additional problems. Like everything, there are advantages and disadvantages that need to be considered for each person's needs or wants. Yep which is why I didn't offer a conclusion or definitive opinion. Methinks the market can accommodate both types of battery systems because everyone's use and environment will be different. What works for one person, may not work for others. In my case, temperature is not an issue as I'm a fair weather rider. For me, price is the major consideration since I don't ride very often or need a headline on every ride. I don't want to make the headlight an investment. Since an internal battery is cheaper, that would be my preference. I forgot to mumble something about the rider that forgets to charge their battery before a ride. If the battery is non-replaceable, they will need to wait until the charger is done charging. With replaceable batteries, a spare charged battery would get them going instantly. Unfortunately, I've had the opposite problem, where I plug a set of half dead batteries into the light, thinking they were charged. Half way into my ride, the lights go out. I always carried spares, even on short rides - you just never know when something may delay you, and having spares also allows you to extend the ride on a whim, or to give assistance to others. |
#26
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Black Friday Deals on Bicycle Lights
On Monday, November 28, 2016 at 8:48:14 PM UTC-5, Phil Lee wrote:
Jeff Liebermann considered Mon, 28 Nov 2016 10:38:06 -0800 the perfect time to write: On Sun, 27 Nov 2016 21:20:15 -0800 (PST), Sir Ridesalot wrote: A non-removable battery can not be switiched out on a very long ride in the dark. I beg to differ. The various "soft power switch" devices I've dealt with, which lack a proper DC on/off switch, draw very little current when off or in standby. Just about every laptop is like that, with power being applied only to the switching circuitry and where the full DC power does not go through the tiny on/off push button. I think you've misunderstood - by "switched out" I believe Sir means exchanged for a fully charged battery. If the battery is not removable, you would have to either carry a spare light, or limit the length of night rides to the battery duration. A non-removable light can lose a fair bit of charge when it's very cold outside. You might be looking at it backwards. A LiIon battery has a very low self discharge rate when cold, and looses more power when warm: http://powerelectronics.com/mobile/designing-battery-packs-thermal-extremes http://powerelectronics.com/site-files/powerelectronics.com/files/archive/powerelectronics.com/images/0606batterypacks-Figure04.jpg Self discharge happens without any load, so a tiny amount of current needed to run the on/off switch doesn't even show on the graphs. What does happen is the battery looses capacity when cold: http://images.slideplayer.com/16/4877973/slides/slide_13.jpg When cold, the battery simply will not run the light as long as it would if it were warm. Actually, that's not quite right because there is no loss of available power. If you charge a battery at 25C, put it in the cooler at 0C, raise it back to 25C, and then run a discharge test, it will show the original 25C battery capacity. Nothing is "lost" when cooling the battery. Except the ability to operate at that low temperature. Once in operation, the internal temperature can be maintained simply by the battery's own chemical action (if it's fairly well insulated), but if you can't get it to START powering the light, you are stuck. Then the ability to stick the battery in your armpit for a while can be very handy, and having it permanently installed in the light makes the package bulkier and more difficult to carry in such a warm spot, as well as providing thermal insulation which means you must keep it in that warm spot for longer before the battery itself is warmed enough. An external b attery pack can be tuck up under one's jacket to warm the battery and keep it runninh longer. It's what I do in winter on lond rides in the dark. Yep, that works to improve battery capacity. Running the light cold is not a good idea, which would be a problem if the battery were non-removable. I suppose I could add a small chemical heater to the light assembly, but that would create additional problems. Like everything, there are advantages and disadvantages that need to be considered for each person's needs or wants. Yep which is why I didn't offer a conclusion or definitive opinion. Methinks the market can accommodate both types of battery systems because everyone's use and environment will be different. What works for one person, may not work for others. In my case, temperature is not an issue as I'm a fair weather rider. For me, price is the major consideration since I don't ride very often or need a headline on every ride. I don't want to make the headlight an investment. Since an internal battery is cheaper, that would be my preference. I forgot to mumble something about the rider that forgets to charge their battery before a ride. If the battery is non-replaceable, they will need to wait until the charger is done charging. With replaceable batteries, a spare charged battery would get them going instantly. Unfortunately, I've had the opposite problem, where I plug a set of half dead batteries into the light, thinking they were charged. Half way into my ride, the lights go out. I always carried spares, even on short rides - you just never know when something may delay you, and having spares also allows you to extend the ride on a whim, or to give assistance to others. Thank you Phil. You are correct. Switching out the battery does mean removing the battery and replacing it with a fresh one. Where I live it's dark now about 4:30 PM and I do a lot of night riding. I've had instances where I've had to remve the battery pack from my water bottle holder and put the battery pack inside my jacket in order to warm it enough to use. I've also had times when I need to replace the battery whilst on a nigh ride. By changing the connectors on the battery and on the cable that leads to the light from the battery holder, I was able to buy other batteries for half the price at a model radio-control shop. With those extra battery packs i can head out for an all night ride even in winter if I want to. The light is a Cygo Lite Rover II and its external battery pack is fitted inside a casing designed to fit snuggly inside a water bottle holder on the bike frame. This light is quite good and lights up the road far betterthan almost any flashlight-come-bicycle-light does. The latter usually has too narrow a beam to see both lanes of a 2-lane road and seeing thiose 2 lanes is need when I ride in the country wherethere is no other lighting on the roads. Cheers |
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Black Friday Deals on Bicycle Lights
On 11/28/2016 6:01 PM, Sir Ridesalot wrote:
Thank you Phil. You are correct. Switching out the battery does mean removing the battery and replacing it with a fresh one. Where I live it's dark now about 4:30 PM and I do a lot of night riding. I've had instances where I've had to remve the battery pack from my water bottle holder and put the battery pack inside my jacket in order to warm it enough to use. I've also had times when I need to replace the battery whilst on a nigh ride. By changing the connectors on the battery and on the cable that leads to the light from the battery holder, I was able to buy other batteries for half the price at a model radio-control shop. With those extra battery packs i can head out for an all night ride even in winter if I want to. The light is a Cygo Lite Rover II and its external battery pack is fitted inside a casing designed to fit snuggly inside a water bottle holder on the bike frame. This light is quite good and lights up the road far betterthan almost any flashlight-come-bicycle-light does. The latter usually has too narrow a beam to see both lanes of a 2-lane road and seeing thiose 2 lanes is need when I ride in the country wherethere is no other lighting on the roads. While it may be harder to put a light with an internal battery under your arm in cold weather, the flip side is that with any LED light you're generating a lot of waste heat that's being dissipated by the heat sink (generally the aluminum case). That waste heat will warm the battery compartment. With an external battery pack you don't have that advantage. The best option for cold weather is a removable internal battery where you can warm just the battery but Jeff had a good list of the reasons to use non-removable batteries. The increase in reliability is probably worth the trouble it is to replace "non-removable" batteries when they lose capacity. How many of us have had to deal with broken battery covers and bad spring-loaded connections on various devices. It's not just for planned obsolescence that more and more devices have non-user replaceable internal rechargeable batteries. To me, the big advantage of user-replaceable batteries is the ability to carry spares for longer duration. Apparently that is not of paramount concern with longer lasting internal batteries. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
#28
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Black Friday Deals on Bicycle Lights
On 11/28/2016 2:00 PM, Jeff Liebermann wrote:
On Mon, 28 Nov 2016 08:08:55 -0800, sms wrote: On 11/27/2016 6:52 PM, Jeff Liebermann wrote: snip A non-removable battery also: 1. Allows for an internal charge controller. There are lights (and many other devices) with internal charge controllers that have removable batteries. Ever since my Canon G2, I've preferred digital cameras with internal charge controllers (though the batteries can also be charged externally). The trend seems to be towards external chargers, especially in the tool business. The idea is that you buy two batteries. One battery is on charge while the other is being used in the tools. My various DeWalt tools are supplied with 2 batteries using that philosophy. I have a similar system for some of my cameras and cell phones. I have spare batteries and external chargers for each of them, even if they are capable of internal charging. I find that things tend to work better and last longer if I do the charging externally with a timed, balanced, and monitored charger, than with a minimalist internal charger. My theory is that if an internal charger or battery management system was provide with a non-removable light, the manufacturer would provide a better quality charger, with a coulomb counting fuel gauge, that is customized to properly charge only the attached battery. It may get its power from an external automotive +12V source, but the actual charging circuit is separate. In order to have the light and battery survive the warranty period, the charger could need to be battery than rudimentary. That would a little more difficult to do if the charge history was reset every time the battery was removed from the light, or when a different brand or chemistry cell was introduced. All your fussing and scheming makes me glad I'm using dynamo lights. -- - Frank Krygowski |
#29
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Black Friday Deals on Bicycle Lights
On 11/28/2016 10:56 AM, Joerg wrote:
On 2016-11-27 10:39, jbeattie wrote: You need 1000 lumens during the day? On roads, yes. Because, you know, Danger! Danger! -- - Frank Krygowski |
#30
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Black Friday Deals on Bicycle Lights
On Monday, November 28, 2016 at 10:14:20 PM UTC-5, Frank Krygowski wrote:
Snipped All your fussing and scheming makes me glad I'm using dynamo lights. -- - Frank Krygowski I just knew you'd be chimijng in with a dynamo hub comment. VBEG LOL The problems with many dynamo hubs and lights is that #1 they're not easily transferable amongst bicycles one owns and #2 they are often far too dim at low speeds to be useful. I tried a quality dynamo at a bicycle shop one night and the light at low speed flickered far too much to be useful - it was nearly as bad as trying to ride at night on dark roads whilst using a strobing light. thanks but no thanks. my battery light works very well for me and it has for 9 years now. Cheers |
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