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A new worry for me- are Lipos safe?


paul devereux
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17 minutes ago, toto said:

So I need to make up extension leads from my charger to the battery to give enough length to place the battery into a charging bag.

 

I'll post up a picture of my charger and battery set up later when I get the chance.

 

Cheers

 

Toto

 

And get longer balance leads........

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Have been flying electric for a long time but never had a lipo. Having heard the stories about lipo fires, I started with those round life cells and have continued to use only life power batteries. The performance is not as good as lipos of course, but is good enough for my sport flying needs. My club mates take the mickey but I am less worried about forgetting to watch over the charging process. However, perhaps we should be as careful with life batteries as lipos. Would be interesting for me to know what life battery fires and accidents there have been in modelling or otherwise.     

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Does anyone watch Battlebots on TV an American version of Robot wars.

They regulary have lipo fires and dont seem to worry about it

After the battle they just go in with an extinguisher put the flames out and use an extractor to get rid of the fumes. 

No paranoia, spectators just cheer more!

 

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4 hours ago, Nigel R said:

 

London Fire Brigade seem fairly unbiased on this front.

 

 

 

The LFB should not be biased .The petrol and diesel car fires were most likely easily put out . Infact lots of those were more than likely put out by turning the ignition off or disconnecting the battery. In those statistics you will also have calls to " Fire all out" when the brigade attends to check its all safe. Until you read the actual fire reports for each incident the statistics are not that meaningful.

EV fires are a different situation all together if the drive battery is involved as once they are burning its game over and the brigade can only protect surrounding area .

Now the government has im told given advice on dealing with Ev's involved in a RTC . If any bodywork or suspension or underbody is damaged or suspected of being dansged then the car has to be transported on a flat bed to a repair center. It cant be towed . Its then recomended that its put in quarantine with 15 m around it clear ! For a period of time not clear how long , beford geing repaired. 

Like anything else dont believe statistics as they can be interpreted in many ways to suit the agenda of whoever is rwading them.

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This has got me thinking, as it should do. As modellers most of us are aware of the potential hazards and indeed discuss this on a regular basis, such as this very thread. However as a modeller I charge my lipos in a safe place but I charge my mobile phone, power tools, domestic items etc etc indoors. I don’t suppose there are long threads discussing the dangers on vacuum cleaner forums or mobile phone users discuss these things at great length. Yes we have heard of the odd case phones, e-cigarettes, and someone mentioned bikes on here.  So is there a difference due to battery chemistry? Or as modellers do we think more about these things ?  As I say I charge my flight batteries with care but only yesterday, without a thought charged my hedge trimmer in the dining room. I don’t charge flight battery’s in my workshop but electric tool batteries sit happily on the shelf on charge. Even in the model world I charge my transmitter with the lithium battery installed upstairs on the bedroom floor. Should I charge my toothbrush outside in a tin box. What are you guys thinking, or like me did you not give it a thought

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I get where you coming from . Phones and houshold items have built in protection for the cells that have to failsafe to open circuit. These boards also limit discharge to what the cells are easily capable if without overheating .So these are or should be far safer in use than our lipos. If these protection boards were fitted to our models then we would have them shutting down when battery is low. Not a good situation.

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The use of lithium ion or lipo batteries in common household appliances isn't really the same thing. As stated above most of these are equipped with electronic circuity onboard to protect against overcharging, cell inbalance , are often in hard cases and are not subjected to the environment that our models encounter regularly. A comparison can be made with the so called intelligent batteries, such as those provided with the higher end of the drone market, which contain similar protections and simply will not allow you to abuse them or overdischarge them, discharge them at too high a rate, or down to a damaging voltage. They also won't let you store the batteries for more than a few days with a full charge, arranging their own self discharge by embedded software.

 

However, even with all those protections there are still examples of mobile phone and laptop batteries swelling and catching fire in use - but the key difference is in the presence of that protective circuity, which our bare, dumb lipos don't have. The soft cases that our lipos have, in order to save weight and improve their energy density by weight, also puts us at risk of mechanical damage to our batteries, which is not present for other consumer users. As ED says, the consequences of our batteries being equipped with such circuitry and cutting power just when you need it, is worse, in our game, than it would be for a model boat or model car. As in the days of NiCds for motive power model car racers tuned their cars to grab every last ma out of their NiCd and if the car coasted to a halt half a lap after finishing the race that wasn't important to them - our batteries running out half way round the last landing circuit is less desirable and becomes much less desirable the larger the model.

Edited by leccyflyer
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Answering a couple of questions raised above.

 

LiFe batteries use Lithium Iron Phosphate which is less chemically reactive than the lithium cobalt oxide or lithium manganese oxide typically used in Lipo batteries. This is why they have lower C ratings and need to be larger / heavier for the same capacity. This makes the LiFe batteries safer as they are less likely to catch fire. Some car batteries are now converting to lithium iron phosphate and boats, caravans and RVs use this type aswell. However, for objects where weight and volume are key they do not tend to find favour.

 

The issue of why we often charge phones etc. In the house has been raised and answered very well above by @leccyflyer. One key difference in RC flying what we consider as normal use, i.e. discharging the battery in 3 to 10 minutes is actually abusing the battery, in no other application is a battery discharged as quickly, cars, phones, laptops, power tools, ebikes etc are all discharged over periods of 1 to 24 hours. Even those of us who look after our batteries well will get cycle lives measured in 100s of cycles so our cells age very quickly and if not monitored can lead to charging problems. Another factor is lithium batteries do not like being charged when cold and this can damage them, but we often keep them in sheds, garages, so do people prewarm them or just charge them. I keep mine in a temperature controlled store during winter to avoid this.

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Does anyone check if their charger's cell balance voltage readings are identically calibrated ? 

The first charger I bought with cell balance turned out to be badly calibrated. Balanced charges took ages & often exceeded the time limit but non calibrated charges usually were reasonably quick. Long story short - after 4 or 5 of my 3s batteries suffered faulty cell each (middle cell each time) I checked the individual readings of the charger against my DVM - calibrations were all over the place resulting in the centre cell being overcharged. I often wonder if this has been the cause of some of the fires with cheap fake copy chargers. 

Since then I check any new charger's the balance voltage displays against my DVM.  

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13 hours ago, toto said:

I must admit Paul, I'm a bit surprised that you never knew about the dangers of LIPO batteries. Conversations rage all over the hobby on forums and clubs almost on a daily basis.

 

I'll be honest, I'm a bit scared of using them and I must have around 20 of various types but go on the basis that just treating them with respect and being aware of the dangers will give you a reasonable chance, however, you could be one of the unlucky ones that fall foul of them and without apparent reason or misuse ..... end up with a bad experience.

 

I never leave them unattended whilst charging ..... usually always in the shed. I try to go on a self imposed ban on having them in the house. 

 

I dont like having fuel stored on the shed either but I am slowly coming to the opinion that it may be the lesser of the two necessary evils. I'll see how I get on with my glow models and of happy with them ..... and the mess and smell, may phase put lipo's where possible and only use them in specific circumstances for example my twin's where I think electric is the most operationally safest way to go in terms of engine 's cutting out etc.

 

Bottom line ..... treat them with care and respect, store them in explosion proof bags.

 

Toto

Well, I don't belong to a club; and as other posters have said, laptops, e-scooters and mobile phones have been known to spontaneously ignite, but it doesn't stop people charging them in their living rooms (or even bedrooms when it comes to mobile phones).  Come 2030 when we are all driving e-cars, there will be charging cables draped over pavements and all sorts of things like that when people without their own driveways need to charge their cars. I'm lucky in living in a detached house in the sticks, but when all the flat-dwellers and terrace-house people start using EVs it is going to be mayhem!

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I wont try and predict the future of where the car policy is going in the future, I'm sure these ambitious electrification targets will change well before 2030 as they are unattainable from a infrastructure point of view as well as economically. 

 

Going back to LIPO's though and regardless of some folks current behaviours in charging their mobile phones and laptops etc ..... these appliances seem to be considered considerably safer than the LIPO batteries that we use and discuss in this context.

 

You have mentioned on a few occasions that you are not a member of a club ..... maybe sometimes as a suggestion that that's why you are unable to gain access to information or keep abreast of certain events. 

 

Does this not tell you something .... that maybe you should be looking at the practicalities of joining a club in your locality if you can and enriching yourself in what could be made available to you as a result of joining ?

 

I've found that joining my club that it's been the single most beneficial thing that I have done ( given the physical flying experience that a forum cant provide ) .... joining here comes a very close second.

 

Look into a club.

 

Cheers

 

Toto

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6 hours ago, gangster said:

This has got me thinking, as it should do. As modellers most of us are aware of the potential hazards and indeed discuss this on a regular basis, such as this very thread. However as a modeller I charge my lipos in a safe place but I charge my mobile phone, power tools, domestic items etc etc indoors. I don’t suppose there are long threads discussing the dangers on vacuum cleaner forums or mobile phone users discuss these things at great length. Yes we have heard of the odd case phones, e-cigarettes, and someone mentioned bikes on here.  So is there a difference due to battery chemistry? Or as modellers do we think more about these things ?  As I say I charge my flight batteries with care but only yesterday, without a thought charged my hedge trimmer in the dining room. I don’t charge flight battery’s in my workshop but electric tool batteries sit happily on the shelf on charge. Even in the model world I charge my transmitter with the lithium battery installed upstairs on the bedroom floor. Should I charge my toothbrush outside in a tin box. What are you guys thinking, or like me did you not give it a thought

I'm wondering about this too. Lots of electrical items explode or cause fires. I read that toasters are responsible for most house fires. TVs can start a fire even when not on. Reports about e-cigs exploding in pockets, etc.  I'd like to see some stats on the dangers of Lipos compared with other commonly used products. That's not to say they aren't dangerous, but then everything is, even driving. I'll probably stop carrying a spare Lipo in my jacket pocket though, Barbours are expensive.

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26 minutes ago, PatMc said:

Does anyone check if their charger's cell balance voltage readings are identically calibrated ? 

The first charger I bought with cell balance turned out to be badly calibrated. Balanced charges took ages & often exceeded the time limit but non calibrated charges usually were reasonably quick. Long story short - after 4 or 5 of my 3s batteries suffered faulty cell each (middle cell each time) I checked the individual readings of the charger against my DVM - calibrations were all over the place resulting in the centre cell being overcharged. I often wonder if this has been the cause of some of the fires with cheap fake copy chargers. 

Since then I check any new charger's the balance voltage displays against my DVM.  

I retired two chargers recently, because, from my wee battery doctor, they were overcharging the first cell in the pack in a balance charge - that cost me a relatively new pack, which became seriously unbalanced and the charge failed to terminate. It happened on one charger, then it happened on the second, identical charger about a month later, but because I was monitoring it closely no harm was done. The two chargers had performed faultlessly for several years before that.

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21 minutes ago, toto said:

Does this not tell you something .... that maybe you should be looking at the practicalities of joining a club in your locality if you can and enriching yourself in what could be made available to you as a result of joining ?

I don't think a club would suit me, or them. I find the fun of flying is just taking off, having a slow trundle around, then opening the throttle and blatting about with a few rolls, loops, and trying to learn stuff I've learnt on YouTube, then landing close to my feet. Club flying is all about rules and safety. It would bore me and annoy them.

Edited by paul devereux
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29 minutes ago, paul devereux said:

I don't think a club would suit me, or them. I find the fun of flying is just taking off, having a slow trundle around, then opening the throttle and blatting about with a few rolls, loops, and trying to learn stuff I've learnt on YouTube, then landing close to my feet. Club flying is all about rules and safety. It would bore me and annoy them.

If you've not been a member of a club, how would you know what club flying is all about?

 

FWIW, what you have just described is exactly the sort of flying that is extremely common at many clubs - though the order of trundling and blatting around may vary, depending on the pilot.

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44 minutes ago, paul devereux said:

I'm wondering about this too. Lots of electrical items explode or cause fires. I read that toasters are responsible for most house fires. TVs can start a fire even when not on. Reports about e-cigs exploding in pockets, etc.  I'd like to see some stats on the dangers of Lipos compared with other commonly used products. That's not to say they aren't dangerous, but then everything is, even driving. I'll probably stop carrying a spare Lipo in my jacket pocket though, Barbours are expensive.

 

Back in the 1950s there was one model of Murphy TV (the V310) which was notorious for catching fire.  We sold them in the family business and there was a shelf full of them in the Service dept at Murphy's, where I worked as what would be called an intern now (but I was paid a pittance 🙂 ).  IIRC it was a kitchen appliance (washing machine?) that caused the Grenfell Tower tragic fire.  Our dishwasher is quite safe though - it's me (though my wife might disagree about my reliability).

 

Of course toasters are rarely left unattended.  Our Dualit is very simple and easily repaired which is why we bought it - no pop-up feature, just a simple manually operated lever.

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18 minutes ago, Geoff S said:

 

.  IIRC it was a kitchen appliance (washing machine?) that caused the Grenfell Tower tragic fire. 

I'm fairly certain the source of that fire was traced to a badly crimped connection within a fridge or freezer. But I won't name the make in case I'm wrong.

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2 hours ago, paul devereux said:

I don't think a club would suit me, or them. I find the fun of flying is just taking off, having a slow trundle around, then opening the throttle and blatting about with a few rolls, loops, and trying to learn stuff I've learnt on YouTube, then landing close to my feet. Club flying is all about rules and safety. It would bore me and annoy them.

 

Type of comment I've seen many times Paul, mostly by folk who've never tried a club and describe them to suit preconceived prejudice. Your loss frankly, yes you have to bend a little and compromise, but then the other members give you the same back, it just a hobby.

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6 hours ago, PatMc said:

Does anyone check if their charger's cell balance voltage readings are identically calibrated ? 

The first charger I bought with cell balance turned out to be badly calibrated. Balanced charges took ages & often exceeded the time limit but non calibrated charges usually were reasonably quick. Long story short - after 4 or 5 of my 3s batteries suffered faulty cell each (middle cell each time) I checked the individual readings of the charger against my DVM - calibrations were all over the place resulting in the centre cell being overcharged. I often wonder if this has been the cause of some of the fires with cheap fake copy chargers. 

Since then I check any new charger's the balance voltage displays against my DVM.  

Not a DVM, admittedly, however every lipo gets its individual cells checked before every flight with a cell checker, without fail.

The main purpose is to ensure a fully charged battery is going in.

 

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