Home Ruination by Ebike Battery Fire Expulserating PreTerminator™®©℠

[StuartsProjects]

I was never taken in by Blakes 7, ORAC was clearly fake.

I am sure everyone else also noticed that although Blakes 7 was supposadly many many years in the future, ORACs insides contained a bit of 0.1" copper stripboard, labeled as RadioSpares\RSComponents as I recall.

 

[guerney]

I was never taken in by Blakes 7, ORAC was clearly fake.

I am sure everyone else also noticed that although Blakes 7 was supposadly many many years in the future, ORACs insides contained a bit of 0.1" copper stripboard, labeled as RadioSpares\RSComponents as I recall.

Whatever happened to those dudes?

It's a well known fact our future selves in UFOs use wormholes to visit the past to shop, avoiding crushing butterfly wings.

https://en.wikipedia.org/wiki/A_Sound_of_Thunder

 

[guerney]

This Home Ruination by Ebike Battery Fire Expulserating PreTerminator™®©℠ is working well - has provided peace of mind, hasn't prompted me to throw my soon to be flaming battery out of the window. Weather has turned a bit cooler, therefore I have set the motorbike horn to sound 6°C over the ambient 15.8°C air temperature of the room it's charging in. Did a quick test of the horn first via the inline switch, to check function. I'm ready to expulserate my ebike battery within seconds.

 

[StuartsProjects]

It's a well known fact our future selves in UFOs use wormholes to visit the past to shop, avoiding crushing butterfly wings.

Indeed, and unless they subscribe to Amazon Prime, they would not have free delivery.

 

[Az.]

Indeed, and unless they subscribe to Amazon Prime, they would not have free delivery.

I pay £95 per year for free delivery. It is as free as Freeview.

 

[guerney]

Indeed, and unless they subscribe to Amazon Prime, they would not have free delivery.

Millions of years in the future, the immortal perfectly preserved and augmented Bezos brain in a jar fed by blood plasma of genetically matched sacrificial neborns, has forced Amazon employees to travel here in flying saucer time machines to trim entire family trees of anti-Galaxiters by anal probe death before they are born, for tax reasons. They daren't risk being seen by anyone else, lest it lowers future profits. Galaxit means Galaxit! Flying saucers solved.

 

[guerney]

So to paraphrase the CSA briefed the IO, the IO examined the charger and battery and briefed the Coroner who officially concluded they probably didn't match. Bike chargers and batteries of 36V and 48V look very similar before they're burnt, although in this case the parts may have been distinctive or the labels may have survived.

There's nothing to say the conclusion's wrong but the probable explanation sounds as though it could be an assumption, which would delay recognising a true cause that's any different, such as a sub-standard BMS not cutting off the correct charger when the first cell hits HVC. Fire services have updated their ebike fire reporting but it would still be useful to have more detail.

Or perhaps charger component(s) failure causing sudden output of high voltage? I recall @Nealh saying one of his did that but he caught it early - does anyone know how often that happens? Should I solder on one of these to cut voltage at 42.2V?

https://vi.aliexpress.com/item/1005006950914995.html

Is there a convenient and cheap gizmo somewhere out there which switches on power supply upon detection of a user defined voltage? If so, I could cobble together a second alarm to sound at 42.2V, and use with my Ebike Battery Fire Expulserating PreTerminator™®©℠, which I never charge my battery without:

https://www.pedelecs.co.uk/forum/threads/home-ruination-by-ebike-battery-fire-expulserating-preterminator%E2%84%A2%C2%AE%C2%A9%E2%84%A0.46934/


Physical evidence would likely be completely destroyed of course, but there ought to be receipts emailed listing basic specs of anything bought new online such as the charger, or more complete specs via links through the user account of the platform it was bought from, for particularly grittily warty and unpleasantly determined hard boiled gumshoes to find.

The cheap convenient gizmo is that same item, it could either cut the charger (NC contact) or power a second alarm (NO contact). But recall saneagle's wise words, basically you need to be sure that safety gear's reliable.

Aha! Yes, thank you, I realised the same gizmo could do that a short while ago, silly me.

Re: safety gear reliability: The Ebike Battery Fire Expulserating PreTerminator™®©℠ is separately mains powered, and situated a safe distance away, with only the heat probe making contact with the battery via a long wire - that failing wouldn't be much of a worry. What shape would failure of that gizmo take? Puff of magic smoke? A small fire? Either would set off the smoke alarm. I can cope with anything but explosion. Of course by the time igniteable smoke is produced by the battery, it's far too late to do anything but run.

Ordered it out of interest...

https://www.aliexpress.com/item/1005006950914995.html

The insidious and sticky nature of the dark patterns of AliExpress sales forced me to buy oodles of other cheap and possibly useless tat I only visited to buy two items, ended up buying 22! I really should put AliExpress.com on my firewall blocklist. Mind you, this sale is pretty good.

 

[guerney]

I'm quite happy with my Home Ruination by Ebike Battery Fire Expulserating PreTerminator™®©℠ in it's current incarnation, but I notice Bobby (you all know Bobby right? Knows a thing or two about batteries does our Bobby, whoever this Bobby guy is) pointing out four temperature sensors which switch off the charger, in this short "MAJOR DIFFERENCES between UL2271 battery and NON CERTIFIED" public information video on antisocial media. FF to the 2 minute mark:

11K views · 87 reactions | Why do PMDs catch on fire while charging? Bobby explains 3 MAJOR DIFFERENCES between UL2271 battery and ❌NON CERTIFIED batteries. | By Mobot | Facebook

Why do PMDs catch on fire while charging? Bobby explains 3 MAJOR DIFFERENCES between UL2271 battery and ❌NON CERTIFIED batteries.

www.facebook.com

I can't increase cell spacing, and I guess there are more temperature sensors within the pack... but it wouldn't be impossible to drill four holes into the casing, fit waterproof-ish connectors...

Pardon our interruption...

...connect them to four temperature sensors covered with heat conductive electrically insulating silicone sheet (in case they fall off) glued to the pack, in order to monitor temprature within the battery case while charging, and set off an alarm when any of the sensors reach 65°C, connect a relay to turn off power from the charger, or (if you have genuine STC-1000) program a small compute module to record data, sound the alarm, and discontinue charging. Bodge retrofit a poor imitation of that part of the UL2271 spec. Wouldn't be impossible to make a system which switches off power if overheating is detected while the battery is in use either.

I just found this BMS on Aliexpress. It has three temperature sensors, active balancing via Bluetooth, switch, and can be configured for different cell voltages and number of series strings. It also has a UART port. I wonder what that can do?

JBD Smart LiFePO4 BMS 6S 8S 12S 13S 14S 16S 20S 21S With Bluilt-in Bluetooth 40A 80A 100A Balance Board Uart Function For E-bike - AliExpress 44

Smarter Shopping, Better Living! Aliexpress.com

vi.aliexpress.com

Communication with the charger perhaps, to stop charging when either of the two external temperature sensors or one internal or all or some permutation of the three detect 65 degrees Centigrade? My one somewhat more external temperature sensor sets off a 12V 120db bike horn, which stops me charging my battery and starts me throwing it out of my window.

Home Ruination by Ebike Battery Fire Expulserating PreTerminator™®©℠

Consider this a trailer promoting my easy to assemble ebike battery safety contraption. Photos with details and an ever so slightly better video will follow.

www.pedelecs.co.uk

I reckon it's probably Chinese BMS maufacturers starting to anticipate greater demand for cheap but safer batteries.

 

[guerney]

As long as no real time output to display is needed.
Very little coding if none at all required to capture data and broadcast it with existing tech frameworks.
there are a few configurable f/w systems for popular esp8266/32 socs. Im most familiar with tasmota which will host a web server of config pages so you can configure h/w like temp sensors etc and dictate where and at what frequency logs should be sent in the json/mqtt format over wifi. (other logging available such as *nix syslog..)

A further capture and record device hosting a mqtt broker with storage would be needed (your fone?), though i would use a PI-zero-W to host a wifi network to recieve the mqtt or syslog broadcasts and format the useful data accordingly (i would probably use node red - gui - easy) total cost circa £25-30 + sensors ( asuming you have a powerbank/5v feed available to power the pi-zero.. more otherwise.

( there are <5 client mqtt brokers that can run on an esp8266 but would require coding and h/w to log to storage)

Check tasmota wiki for supported h/w -sensors for input if not there you would need to add to the sources and recompile ( real programming) but not impossible. there are quite a few though..

Alternatively if you find cheap off the shelf ble sensors you can accomplish pretty much the same with the OMG project- Open Mqtt Gateway f/w for an esp32..

- I had plans... but the frequency my back box has been knocked off my bike has slowed my pace asI had planned to house my 'bike brain' within the gap of 2x stacked boxes at the rear.


** MQTT is a messaging protocol that can handle long text strings great for mark up languages like xml json...
A Broker is required to receive and repost mqtt messages, without one your literally whistling into the wind, data gets lost. Its a whole thing worth the 10 mins or so to swallow the basics might take a couple of sessions for it to sink in??
Mosquitto is the broker i employ on the same h/w above , Pi-0-W(v1).

Node Red is a Gui tool accessed via a web interface that is MESSAGE based, create flows that manipulate and change the message as it passes through the flow, THIS IS A PARADIGM SHIFT from traditional coding, but once the penny drops.. its easy/powerful, took me a bit of time tbh tho flow #1 was a monster and about 90% the way through I though hang on .. and reduced it to a handful of nodes..

what i mean to say-- not that tricky and if you want a hand to get going im happy to point..

Thanks for taking the time to write that interesting post. What I really want is a robotic hand which presses a button on a window handle, turns it, then undoes the latch which prevents the window opening fully, then opens the window wide, and presses a button to activate a conveyor belt to throw my soon to be aflame battery out the window at at 0.5mph into the water butt filled with water below. For when I'm out. Then it has to close and relatch the window etc. to prevent my bike being stolen, and ideally look for a good deal and order another battery.

 

[thelarkbox]

Thanks for taking the time to write that interesting post. What I really want is a robotic hand which presses a button on a window handle, turns it, then undoes the latch which prevents the window opening fully, then opens the window wide, and presses a button to activate a conveyor belt to throw my soon to be aflame battery out the window at at 0.5mph into the water butt filled with water below. For when I'm out. Then it has to close and relatch the window etc. to prevent my bike being stolen, and ideally look for a good deal and order another battery.

Probably cheaper and a lot easier to knock out a specialised battery exit vent..

 

[guerney]

Probably cheaper and a lot easier to knock out a specialised battery exit vent..

Yep, conveyor belt hurling the battery through a RFID secured catflap in the window or door...

 

[guerney]

Motivated by this (and the related thread) I too implemented an external temperature monitoring + alarm.


But, being unsure how effective such a system would be, I did a quick and dirty simulation of heat transfer from the center of a battery pack to outside assuming one of the cells develop a runaway event and it then propagates into neighbouring cells. The results are sobering unless I made a mistake: it does take several minutes for the event to spread, but the temperature of outer cells remain rather low (close to room temperature) for a long time. The temperature of the enclosure rose by 10 to 20C only when the runaway had spread to a few cells, and from that point it rose rapidly to be useful for an alarm system.


I think one has to tap into the temperature signal of the BMS and hope that there are enough temperature sensors distributed over the pack to detect the failure much earlier.


Though I might have made a mistake, I found a more sophisticated simulation online with similar results:

/https://www.comsol.com/model/download/1345961/models.battery.thermal_runaway_propagation.pdf

This small collection of gizmos:

Home Ruination by Ebike Battery Fire Expulserating PreTerminator™®©℠

Consider this a trailer promoting my easy to assemble ebike battery safety contraption. Photos with details and an ever so slightly better video will follow.

www.pedelecs.co.uk

...only needs to buy me about 30 seconds advance warning, hopefully a minute or so, so I can expulserate my soon to be explodey battery via my window, or in the case of the on-battery version jump off my bike and flee, or break a train window to expulserate it via, not to prevent thermal runaway. Judging by the speed temeprature rises while charging, I believe it will buy me sufficient time, while charging or resting in storage at least. It's a heck of a lot better than waiting for ignitable smoke to set off a smoke alarm, at which point it's far far too late to do anything but kiss your home and belongings goodbye and run away as fast as possible. You lot can do what you like.

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.

I'm not so sure, and I'm not sacrificing my battery or cell-less enclosure prematurely to find out. I suppose I could buy an emoty battery enclosure and place probes both inside and out to see how fast temperature rises with a heater placed within, but I can't be bothered. I'm that sure.


The mobile version could have a heat probe placed within the enclosure - I'd only assemble and install the gizmo if my worry about transporting my ebike battery on trains becomes overwhelming. Currently, it isn't.

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.

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.

Further to the posts above and this video:

A quick and dirty experiment (my favourite kind): After covering gaps on the sides of the battery case cover with parcel tape, to contain air, I shot this exceedingly boring video you shouldn't watch under any circumstances, showing temperature measured with the sensor situated on the exterior of the case, with the case placed over a small milk jug containing freshly boiled water. Six degrees above 22.7°C happens in about 65 seconds (skip to that bit, save more than a minute of your precious life for gawd's sake). There's much less air within the case with the battery pack present, and flaming battery cells are substantially hotter than air circulated by the heat from a small milk jug filled with freshly boiled water, therefore I believe I will have enough time to expulserate my soon to be flaming battery via the window sufficiently long before toxic and explosive smoke is forced out from the battery case. Of course it'd be better having a bunch of temperature sensors all over and within the battery pack rather like the UL 2849 safety standard, but I can't be bothered. This'll do. You lot can do what you like.

For some reason the 12V bike horn stopped working, so I'm going to replace it with a couple of these (supposedly) 75db buzzers = 150db, (or something else) which should be louder, drawing much less current. Power supply is fine, tested with a smaller version of these.


https://www.ebay.co.uk/itm/253022844478

 

[saneagle]

Further to the posts above and this video:

A quick and dirty experiment (my favourite kind): After covering gaps on the sides of the battery case cover with parcel tape, to contain air, I shot this exceedingly boring video you shouldn't watch under any circumstances, showing temperature measured with the sensor situated on the exterior of the case, with the case placed over a small milk jug containing freshly boiled water. Six degrees above 22.7°C happens in about 65 seconds (skip to that bit, save more than a minute of your precious life for gawd's sake). There's much less air within the case with the battery pack present, and flaming battery cells are substantially hotter than air circulated by the heat from a small milk jug filled with freshly boiled water, therefore I believe I will have enough time to expulserate my soon to be flaming battery via the window sufficiently long before toxic and explosive smoke is forced out from the battery case. Of course it'd be better having a bunch of temperature sensors all over and within the battery pack rather like the UL 2849 safety standard, but I can't be bothered. This'll do. You lot can do what you like.

For some reason the 12V bike horn stopped working, so I'm going to replace it with a couple of these (supposedly) 75db buzzers = 150db, (or something else) which should be louder, drawing much less current. Power supply is fine, tested with a smaller version of these.


https://www.ebay.co.uk/itm/253022844478

Congratulations! That video was more boring than Perun's. I'd give you a medal for it, but it would be a waste of time because you don't have a chest to put it on. I'm going to send a link to Perun as a punishment for his ones.

 

[thelarkbox]

I suspect your 12v horn and the buzzers linked to will be designed for a short duty cycle and continues use may just fry them if just switched on and powered by the stc1000's relays or even if your bleeding off the 12v switching power to the relay coil.

Look at home alarm solutions perhaps which are intended for longer duty cycles than something expected to beep or chirp. Or consider a timer delay post relay pre buzzer.

 

[eas2lv]

I suspect your 12v horn and the buzzers linked to will be designed for a short duty cycle and continues use may just fry them if just switched on and powered by the stc1000's relays or even if your bleeding off the 12v switching power to the relay coil.

Look at home alarm solutions perhaps which are intended for longer duty cycles than something expected to beep or chirp. Or consider a timer delay post relay pre buzzer.

I use a buzzer recycled from an old smoke alarm. Appears to work fine though haven't tested beyond a few tens of seconds.

 

[guerney]

Congratulations! That video was more boring than Perun's. I'd give you a medal for it, but it would be a waste of time because you don't have a chest to put it on. I'm going to send a link to Perun as a punishment for his ones.

I couldn't bear to watch it, it's even more boring when you know what happens.

I've got the body of a 25 year old. I keep it in a wardrobe.

I suspect your 12v horn and the buzzers linked to will be designed for a short duty cycle and continues use may just fry them if just switched on and powered by the stc1000's relays or even if your bleeding off the 12v switching power to the relay coil.

Look at home alarm solutions perhaps which are intended for longer duty cycles than something expected to beep or chirp. Or consider a timer delay post relay pre buzzer.

You're right - I'd soldered in a manual override switch to annoy my bloody awful neighbours with the 12V horn, at strategic times for maximum discomfort, while wearing ear defenders, but I never sounded it longer than ten minutes at a time. I've ordered an intermittent buzzer, also a continuous, with flying leads, else they're really fiddly to solder with such tiny contacts, plus another 12V bike horn I might use for something else.

https://www.ebay.co.uk/itm/154997541418?var=455163094358

https://www.ebay.co.uk/itm/265582347459