Who has First Hand experienced a LiPo fire ?

[KenC]

During service we had an incident several miles away from where I was. Someone walked over to a butane cooker that had gone out and tried to re ignite.  Not the  best idea in a confined space..... no part of him was ever found , and the resultant fire spread to the munitions storage part of the station. The resultant activity caused us to prepare for WW3 ... I can assure you munitions in boxes are no match for that heat , and their trajectory is horrifyingly random.  Many days later it was found the heat produced in the fire bent and warped rifle barrels !     

 

Sometimes when I read of the issues of electric flight , short durations , high price batteries , expensive chargers, dangerous storage .... a little voice in my head screams DLE 20 !

[David Davis]

33 minutes ago, KenC said:

 

 

... Sometimes when I read of the issues of electric flight , short durations , high price batteries , expensive chargers, dangerous storage .... a little voice in my head screams DLE 20 !

 

Nah, Laser 155!

 

[Phil Green]

Ok I concede the pressure thing, a squaddy pal had said ammo boxes were to contain an internal firing through impact or heat   🙂

[KenC]

 

[KenC]

The price mounts , the above box is around £60 to charge or store up to 2 6S 5000  units . It however looks like not only a better solution than a charging bag ( which in videos of fires look useless)  It is also a rather easy way to pick up and take to the field, safe in the knowledge that the smoke emits whiles the outer is cool enough to grab the handle and eject from the car.  It could be used in conjunction with an Amo box, purely  for storage of more items long term.  Rather neat that the charger fits on a stand attached and the wires pass through the case so that charging is in a sealed, vented box

[David perry 1]

2 hours ago, Martin Harris - Moderator said:

Working on the principle of the Davy screen? Obviously not as effective as a fine mesh but useful by the sound of it. 
 

I’m not at all sure that suggestions of a sealed container in some posts are the way to go - they sound too much like a potential bomb!   A fire resistant container incorporating a fine mesh protected vent seems the best hope to be able to either contain or limit the effects of a small LiPo fire. 
 

Has anyone seen or have knowledge of such a device?

I think all references to sealed ammo boxes also include a phrase along the lines of...sealing gasket removed.

 

Ive seen some drilled and grommeted to allow charging leads through  as well.

 

All you want is to stop the flaming carcase setting fire to anything else.

[KenC]

3 hours ago, David Davis said:

 

Wait for Jon to have a fire sale 🙂  DLE 20 For  £230  against 4Max 5065 360  £76 + Esc £70 + 6S 5000 + Charger £200 + BatSafe £60    = £400+  ... option one buys you a Sunday flight of 8 mins , the other all day  with a few minutes of refueling.  No oily residue in your car , and no fires.

Edited July 2, 2023 by KenC

[Martin Harris - Moderator]

Good job petrol isn’t highly flammable then…

 

Any form of energy storage has its dangers. 
 

[Paul De Tourtoulon]

4 minutes ago, Martin Harris - Moderator said:

 

 

Any form of energy storage has its dangers. 
 

Especially when it's unused brains in a modellers head.

[leccyflyer]

As posted earlier all of my charging in the workshop is done in a pair of Bat Safes - like this.

 

 

The charge and balance leads go through a tight fitting rubber bung in the lid of the box and the box is latched shut, but has a number of small holes, baffled by mesh internally, so that they would vent the fumes, rather than allow them to build up and cause an explosion. Those baffles are supposed to retain the flame front, within the box, so that it doesn't set alight any external flammable materials within reach. That's the theory anyway.

Edited July 2, 2023 by leccyflyer
added link

[GrumpyGnome]

VERY neat!

[leccyflyer]

I think the video above is somewhat and unnecessarily sensational.. The first test showed that with a battery within the spec of the Bat Safe that the flames were completely contained. That Bat Safe has done it's job, but it would then need to be replaced. To then put a larger battery than the design spec permits into a box that has already failed and been compromised is something that you would be very foolhardy to do in practice.  I don't believe that HobbyKing give you a free replacement Bat Safe if it saves you from a fire, but Lipo Sack do. If you have a lipo fire and your Lipo Sack does its job and protects your property from that fire, that Lipo Sack is now compromised and will be replaced by Lipo Sack on request, accompanied by a report of the circumstances.

[MattyB]

5 hours ago, KenC said:

Wait for Jon to have a fire sale 🙂  DLE 20 For  £230  against 4Max 5065 360  £76 + Esc £70 + 6S 5000 + Charger £200 + BatSafe £60    = £400+  ... option one buys you a Sunday flight of 8 mins , the other all day  with a few minutes of refueling.  No oily residue in your car , and no fires.

Option 2 also buys you a boatload of hideous noise, a model storage area that stinks of petrol and a whole lot more ongoing maintenance over the life of the engine  You pays your money etc….

[KenC]

Matty I understand the winging neighbor scenario, however I love the sound of aero model engines ( IC)  as an old timer I also find it easier to judge the speed from the sound etc.  Sometimes I almost feel a sense of disconnect with electric.  I recently changed a full set of bearings on my OS 46FX , and it cost me around £6 all up with postage . 

[PeterF]

On 01/07/2023 at 18:15, Geoff S said:

Lithium batteries are now used as leisure batteries in motor homes and caravans and often left on a float charge (sometimes via solar panels) but there seems to be no publicity in the Caravan Club magazine, which you'd expect if there had been any fires. 

 

Lithium batteries for motorhomes, caravans and boats are lithium iron phosphate (LiFePO4) and are a subtly different chemistry to the LiPo packs used in electric flight. The chemistry is much safer than what we are used to and much harder to get it to ignite. The chemistry is less active hence harder to ignite, but this meansa that for a given discharge rating and capacity the batteries are heavier and larger in volume, which is less of an issue compared to phones, laptops, power tools etc. Secondly, the batteries come with built in battery management systems (BMS) which monitor cell voltages, cell temperatures, cell capacity and charging/discharging currents. If any value goes out of spec the BMS isolates charging sources or loads to protect the cells.

[Geoff S]

12 minutes ago, PeterF said:

 

Lithium batteries for motorhomes, caravans and boats are lithium iron phosphate (LiFePO4) and are a subtly different chemistry to the LiPo packs used in electric flight. The chemistry is much safer than what we are used to and much harder to get it to ignite. The chemistry is less active hence harder to ignite, but this meansa that for a given discharge rating and capacity the batteries are heavier and larger in volume, which is less of an issue compared to phones, laptops, power tools etc. Secondly, the batteries come with built in battery management systems (BMS) which monitor cell voltages, cell temperatures, cell capacity and charging/discharging currents. If any value goes out of spec the BMS isolates charging sources or loads to protect the cells.

 

Although I'm relatively experienced with electronics (it kept me fed and in toys for 40+ years), battery chemistry is not something I'm expert on.  I'm aware there is a difference but not its implications. Moreover, in speech, Lithium Ion sounds much the same as Lithium Iron 🙂   I know the batteries on our electrically assisted pedal cycles have some inbuilt charge control because the supplied chargers are very simple 42v dc.  

 

Thanks for the comment.

[MattyB]

12 hours ago, KenC said:

Matty I understand the whinging neighbor scenario, however I love the sound of aero model engines ( IC)  as an old timer I also find it easier to judge the speed from the sound etc.  

 

To each their own, but I personally can't understand how anyone can "love" the sound of a petrol two stroke, not matter how well they are silenced. I can acknowledge that any other engine has it's own certain charm, especially 4-strokes, but the bark of these two-stroke petrol weed whackers is so harsh and carries like nothing else - they have been responsible for so many noise complaints down the years. No thanks!

 

Edited July 3, 2023 by MattyB

[MattyB]

11 hours ago, Geoff S said:

Moreover, in speech, Lithium Ion sounds much the same as Lithium Iron 🙂

 

Even more confusingly, the lithium iron (LeFe) packs are actually part of the overall class of lithium ion battteries, a family that that includes lipos. It's nto surprising that people get confused!

 

[KenC]

Not that I know anything about the specific chemistries , but did I hear something about new battery design that would make electric cars safer and more efficient.  This was quite recently.

[Martin Harris - Moderator]

21 minutes ago, MattyB said:

 

To each their own, but I personally can't understand how anyone can "love" the sound of a petrol two stroke, not matter how well they are silenced. I can acknowledge that any other engine has it's own certain charm, especially 4-strokes, but the bark of these two-stroke petrol weed whackers is so harsh and carries like nothing else - they have been responsible for so many noise complaints down the years. No thanks!

 

Even as a dyed in the wool lover and operator of IC powered models (although I’m a regular user of EP too) I can almost agree with this viewpoint but it is possible to silence 2 stroke petrol engines effectively and once they are “hiding” behind prop noise they can sound quite acceptable.  I have a (second hand) Zenoah 38 powered model which was built with a silencer based on a die cast electronics project box which exhibits none of the harshness normally associated with 2 strokes. 
 

However, we’re done no favours by manufacturers supplying thin walled open box “silencers” which accentuate the ringing bark - not helped by poorly damped cylinder and head finning.  These can certainly attract adverse attention from uninvolved parties. 

[Martin Harris - Moderator]

3 minutes ago, KenC said:

Not that I know anything about the specific chemistries , but did I hear something about new battery design that would make electric cars safer and more efficient.  This was quite recently.

There are no shortages of such articles!  Rather like reports of researchers making breakthroughs on cures for common diseases…

 

There’s no doubt that a lot of work is going on to develop energy storage but commercial availability is another matter altogether. 

[MattyB]

7 minutes ago, KenC said:

Not that I know anything about the specific chemistries , but did I hear something about new battery design that would make electric cars safer and more efficient.  This was quite recently.

 

These stories are ten apenny, they come out every few days from research groups who are always on the cusp of "a great battery breakthrough". In 99% of cases they are  fishing expditions for investment, and nothing is ever heard of again. There's a thread dedicated to this on RCG if you fancy it, some of the claims are pretty funny...

 

[MattyB]

26 minutes ago, Martin Harris - Moderator said:

Even as a dyed in the wool lover and operator of IC powered models (although I’m a regular user of EP too) I can almost agree with this viewpoint, but it is possible to silence 2 stroke petrol engines effectively and once they are “hiding” behind prop noise they can sound quite acceptable.  I have a (second hand) Zenoah 38 powered model which was built with a silencer based on a die cast electronics project box which exhibits none of the harshness normally associated with 2 strokes. 
 

However, we’re done no favours by manufacturers supplying thin walled open box “silencers” which accentuate the ringing bark - not helped by poorly damped cylinder and head finning.  These can certainly attract adverse attention from uninvolved parties. 

 

I'm sure what you say is absolutely true (I know very little about IC power so am in no position to provide advice!). The problem is how many of these cheap petrol 2-strokes are properly silenced by their owners? Maybe 2 or 3%?

 

With the price of the engines coming down over the last 10-15 years (though probably not since Covid struck I guess...!) more people have "moved up" into these larger sizes of model, but as you rightly point out the silencers that come in the box are completely ineffective. Unfortunately fitting something that does work probably doubles (or more) the costs of the powerplant, and they didn't budget for that of course... Result, a hideously noisy model that the owner wants to fly, but you know could lresult in loss of a site. 

Edited July 3, 2023 by MattyB

[Martin Harris - Moderator]

It rather depends on the engineering ability/desire to reduce the noise. The silencer built by my former club mate would probably cost less than £20 in materials to build at today’s prices and is easily within the capabilities of anyone with basic DIY tools. 

[Andy Stephenson]

43 minutes ago, MattyB said:

These stories are ten apenny, they come out every few days from research groups who are always on the cusp of "a great battery breakthrough". In 99% of cases they are  fishing expditions for investment, and nothing is ever heard of again. There's a thread dedicated to this on RCG if you fancy it, some of the claims are pretty funny...

The best one I read about was the urine activated battery, I thought are they taking the whatsit?

 

Mods note - post edited as using wildcard characters to disguise a word, however apt, contravenes forum rules.

 

Edited July 3, 2023 by Martin Harris - Moderator
Use of wildcard characters