February 1, 20251 yr Safety is enhanced if you treat the battery with caution. Don't charge the battery unattended at night Use a slow charger of correct voltage Periodically check that the charger voltage is still correct (multi meter) Don't draw currents beyond the cell capability by tampering with max current settings Keep the battery enclosure waterproof to protect against BMS failure Make sure the battery is safely constructed and proofed against chafing - shorts can happen in badly constructed batteries through cell wrap chafing Periodically open the battery and inspect it for deterioration or water ingress
February 1, 20251 yr My point was that the temperature sensor has to be placed inside the pack. It may be be too late if you wait for the temperature on the outer surface of the pack enclosure to rise even by 10C. The problem here is that in a chunky battery pack the temperature sensor might be quite a way from a cell which has heated up too much and may not have been able to detect the problem because at that point in time the sensor is still cool while a particular cell is about to go into melt down. I think in order to be sure you would need a number of sensors in the pack - evenly distributed.
February 1, 20251 yr Battery case surface temperature rises fast enough via air convection within the case, for the purposes of flinging out of the window to prevent home conflagration. I suggest you do your own measurements: Edited February 1, 20251 yr by guerney
February 1, 20251 yr If anyone is concerned about fire risk, why not get rid of the sensitive chemistry and go LiFePo4. LiFePO4 has lower self heating rate compared to NMC but that's not enough to prevent thermal runaway and still suffers from oxygen evolution due to humidity and SEI (solid electrolyte interphase) deposition on the anode. Most of the current efforts go on to large EV and storage batteries, we still have no new choice for e-bike batteries other than NMC. Among the improvements, we may have 3D printed electrodes, temperature sensitive separator, adding Li2ZrF6 to the electrolyte for example.
February 1, 20251 yr Battery case surface temperature rises fast enough via air convection within the case, for the purposes of flinging out of the window to prevent home conflagration. I suggest you do your own measurements: This does not show the lag between a thermal event at some point inside the pack and when that reflects in temperature at the surface. As per my simulation and what I saw online, there is a lag of minutes leaving too little time to act on an alarm. One needs multiple sensors inside the pack distributed evenly. Not saying your gizmo is useless.
February 2, 20251 yr This does not show the lag between a thermal event at some point inside the pack and when that reflects in temperature at the surface. As per my simulation and what I saw online, there is a lag of minutes leaving too little time to act on an alarm. One needs multiple sensors inside the pack distributed evenly. Not saying your gizmo is useless. Even if the alarm didn't sound before enough ignitable toxic smoke escaped the case to set off the smoke alarm, I believe it'd sound well before the smoke alarm did. Any additional seconds or minutes of forewarning is welcome. I was intending to do a much better job of recording temperature over time yesterday, but I was in a rush to charge my ebike battery, and there didn't seem much interest about my gizmo's thread, thought it'd further bore people. But I will do so at some point. Prepare to be bored. Simulation is all well and good, but experiment is necessary. I really didn't think there would be any externally detectable temperature change - cheap and easy suited me down to a tee, so I decided to try it, and there is. I suppose you could take a downtube battery top cover, plonk a temperature probe on the top externally as I have, and quickly place it over something something requisitely hot, making sure hot air is trapped inside, and see how fast externally measured temperature changes. I tested using a hairdryer in the very long and boring badly edited promotional video. You're free to place multiple sensors within the pack, rather like the UL 2849 safety standard - that would be much better of course, and I look forward to seeing the results. I prefer easy cheap and cheerful, and that's why I married my wife. Edited February 2, 20251 yr by guerney
February 2, 20251 yr China Encourages Citizens to Swap ‘Old Lithium E-Bikes’ for New Lead-Acid Models https://greekcitytimes.com/2025/01/30/china-encourages-citizens-to-swap-old-lithium-e-bikes-for-new-lead-acid-models/
February 2, 20251 yr China Encourages Citizens to Swap ‘Old Lithium E-Bikes’ for New Lead-Acid Models It's good that they are not obsessed with people using the throttle. E-bikes are about the best and safest form of simple, non polluting cheap transports.
February 5, 20251 yr "E-bikes are about the best and safest form of simple, non polluting cheap transports." Amen to that.... and all of it will be swept away if the Li-Ion Battery Safety Bill gets into law. A modern BMS protects against over-current and over-voltage: over-charging occurs when the BMS isn't up to scratch. The Bill mandates anti-tamper charger interfaces, meaning OEM bikes can skimp on BMS protection and still be compliant despite being less safe. There's little hope of a fully open charging standard: we still haven't settled on a universal plug and proprietary features promise more profits (or so it seems). Without a standard, public charging is an expensive hassle so ebikes as transport won't boom as they could (fewer profits). Instead of being handed down or sold on, when design life expires ebikes will turn from asset to costly e-waste and that will make them reluctant purchases. Safe, simple, non polluting, cheap, transport... booming: all undermined. The Bill has had two readings and is now in committee stage. Anybody got an in with Their Lordships?
February 6, 20251 yr https://news.sky.com/story/two-dogs-die-and-two-homes-gutted-in-separate-e-bike-and-e-scooter-fires-13303531
February 6, 20251 yr "In an announcement via the China Daily news agency, the Ministry of Commerce said absorbed glass mat (AGM) lead-acid batteries are now being preferred by manufacturers for domestic e-bikes. This includes manufacturers like Yadea and NIU. Both companies still export lithium-ion e-bikes for now. E-bike users are being encouraged to turn in their lithium-ion e-bikes as part of a trade-in programme, according to the ministry. E-bikes handed in will be dismantled and batteries recycled. Subsidies will be provided for users to purchase ones with sealed lead-acid batteries, it said. " https://www.bestmag.co.uk/china-shifts-from-lithium-ion-to-lead-acid-batteries-for-e-bikes/ https://www.yuasabatteries.com/resources/guides/agm-battery/ Edited February 6, 20251 yr by lenny
February 6, 20251 yr E-bike users are being encouraged to turn in their lithium-ion e-bikes as part of a trade-in programme, according to the ministry. E-bikes handed in will be dismantled and batteries recycled. Subsidies will be provided for users to purchase ones with sealed lead-acid batteries, it said. " weight isn't a problem for twist and go e-bikes but for EAPC, we need LmFP (Lithium Managnese Iron Phosphate). Tesla is going to use LmFP in their cars by the end of this year.
February 7, 20251 yr I think we need to turn around the message. More and more the forum is gravitating towards why ebikes are a menace, rather than what we ought to be saying which is that they are a great thing which brings older people back to being free and self powering without riding in a metal box. Yeah - I can still pedal a bike which doesn't have electrical assistance, but I like having a bit of help in this hilly area where I live, so that I am flying along like I was twenty once again. Having that technology is a brilliant thing and we need to celebrate it more and stop all the negative stuff. This forum is an advocacy group for that, not one which says why they should be banned and restricted and feared. Show me the transportation system which does not have disasters. Treat them right and none of this cr ap will happen. We know that, and we know how great they are. My £252 Argos e-bike yesterday at 504 miles covered. What a bargain. I love it! I have had such joy riding it.
February 9, 20251 yr Trouble for us with our bike batteries, is when insurance companies decide to not only jack up rates, but Cancel fire insurance, like in California. :-/
February 10, 20251 yr Just what we Don't need, another fire, and worst place, on a plane. Lucky it was on the ground. Powerbanks will get banned I reckon? :-/
February 13, 20251 yr Just what we Don't need, another fire, and worst place, on a plane. Lucky it was on the ground. Powerbanks will get banned I reckon? :-/ I'll wager that whatever it was fitted to was something bought because it was "The cheapest available" But as ever, these cheap products are giving all battery products a bad name, when it is the opposite that is true. Quality is priced accordingly, and as all these instances have proven, buying cheap is a bad economic model.
February 13, 20251 yr Author I'll wager that whatever it was fitted to was something bought because it was "The cheapest available" That's ridiculous. This clearly shows your biased thinking. He said that was a portable battery that got squished in the overhead locker. What's that got to do with price? In fact all the expensive ones look a lot less sturdy to me, as they use pouch cells rather than 18650s that have their own metal case as well as the plastic case around them.
February 14, 20251 yr Salvaged another perfect small lithium battery this morning from a discarded vape, lying in the street. Perfect condition. Measured voltage as found was 3.4v - barely used. It is the useful 500 mAhr type. These cells are rated for hundreds of charge -re-charge cycles. Another torch cell maybe, or a replacement for one of the many applications which use 3 series connected AA, or AAA batteries. The tiny TP4056 charge controllers at eighty pence each make them safe on charge and discharge and they become USB chargeable. This is one less battery that might have caused a fire in the waste stream when accidentally crushed or short circuited alongside flammable material.
February 18, 20251 yr Matured technology TVs, PCs and laptops don't set fire to your homes, chargers and air fryers aren't as safe. See 122 battery chargers, 103% increase, 305 fryers, 30% increase. https://uk.yahoo.com/news/air-fryer-safely-fire-insurance-claims-164935625.html
February 19, 20251 yr https://uk.yahoo.com/news/air-fryer-safely-fire-insurance-claims-164935625.html https://www.youtube.com/watch?v=dq6T5BojXc8:2 https://www.ebay.co.uk/itm/226466146754?chn=ps&_ul=GB&_trkparms=ispr%3D1&amdata=enc%3A1nWC9IvqfRXmXRHsDJpnuQA13&norover=1&mkevt=1&mkrid=710-134428-41853-0&mkcid=2&mkscid=101&itemid=226466146754&targetid=2425733423477&device=c&mktype=pla&googleloc=9190496&poi=&campaignid=21697391927&mkgroupid=162558106770&rlsatarget=aud-1165757154899:pla-2425733423477&abcId=10027104&merchantid=118934736&gad_source=1&gclid=Cj0KCQiA_NC9BhCkARIsABSnSTZLY_9rclOMXMCgVWfpT2UlTkiBmV5brjyQI4I4gF7NSRlgoRwvX-8aAuuqEALw_wcB
February 19, 20251 yr [ATTACH type=full" alt="62054]62054[/ATTACH] Salvaged another perfect small lithium battery this morning from a discarded vape, lying in the street. Perfect condition. Measured voltage as found was 3.4v - barely used. It is the useful 500 mAhr type. These cells are rated for hundreds of charge -re-charge cycles. Another torch cell maybe, or a replacement for one of the many applications which use 3 series connected AA, or AAA batteries. The tiny TP4056 charge controllers at eighty pence each make them safe on charge and discharge and they become USB chargeable. This is one less battery that might have caused a fire in the waste stream when accidentally crushed or short circuited alongside flammable material. If more people were conscious about discarded batteries
February 19, 20251 yr If more people were conscious about discarded batteries If more people were conscious about discarded batteries Fitted with a TP4056 BMS / charge _ discharge controller. I bought 5 of them on ali express and they cost about 80 pence each. This one is ready for a project, when i think of one.
February 19, 20251 yr Make a battery pack for your cycling dashcam? I'm considering whether it'd be worth using two lithium pouches I've dragged out of a Sony VAIP P battery to power my GoPro Hero 7 Black, or a bluetooth amp (The Vamp) - that laptop battery has never been used, incorrect version bought by mistake for a fiver (refunded) on ebay several years ago. They were a right bugger to extricate from the battery housing, and I suspect I may have damaged the things. I also suspect the very strong glue holding them to the battery housing was integral to the design, as there wasn't much else holding the housing parts together. I was going to try disconnecting the pouches from the Sony BMS, to replace identical cells in a dead but compatible VAIO P battery, but I don't have the expensive BMS chip resetting gizmo; not worth it. Might try charging one of the pouches... or simply attempt to recycle. Fortunately, I have a much higher capacity battery for that UMPC laptop. Edited February 19, 20251 yr by guerney
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