What's up with my Lipos?

[leccyflyer]

41 minutes ago, Paul De Tourtoulon said:

tell that to two of our club members, one that has had stitches on his fingers and the other that has a chopped up shirt and a bruised stomach  when they plugged their batteries in, and the third that I was holding his electric pylon racer when it went off full chat when he turned his radio on 🤢

There's no accounting for those who don't follow the most basic of safety protocols - kind of like the guy who reaches through the prop to disconnect his glow leads from in front of the model. If they need the noise of a running motor to tell them not to get in the prop arc, maybe it is best that some folks stick to their sticky models.

[Lima Hotel Foxtrot]

1 hour ago, Paul De Tourtoulon said:

tell that to two of our club members, one that has had stitches on his fingers and the other that has a chopped up shirt and a bruised stomach  when they plugged their batteries in, and the third that I was holding his electric pylon racer when it went off full chat when he turned his radio on 🤢

That's their silly fault for not taking proper precautions. The plane is just an object, it's the user who makes the mistake.

[MattyB]

6 hours ago, paul devereux said:

You're all right, thanks for the info. I suppose if a £8 charger was any good, we'd all use one. I just didn't want to spend more money. In my defence, it is my having to adjust from flying a e/p glider to a plane that needs power all the time. A glider just needs a few a seconds power on launch and a few top-ups. But a power plane needs continuous power so it makes sense to look after the Lipos.

So maybe this will be okay? A decent charger, costing about £50. Four new Lipos, and shorter flights, perhaps 7 minutes each, checking I've got 30% capacity left after each flight? 

 

Please forget the %s that come from a battery checker - they are not the most accurate. Follow @leccyflyer's advice; you can never go wrong by checking the individual cell voltages, and in doing so you will also notice if a pack is going out of balance with use (potentially inidicating one or more cells are on their way out)...

 

2 hours ago, leccyflyer said:

Checking that you have at least 3.7v/cell after each flight. That's the single most important piece of information for monitoring the health of your lipos.

 

👍

 

Edited May 30, 2023 by MattyB

[MattyB]

48 minutes ago, leccyflyer said:

There's no accounting for those who don't follow the most basic of safety protocols - kind of like the guy who reaches through the prop to disconnect his glow leads from in front of the model. If they need the noise of a running motor to tell them not to get in the prop arc, maybe it is best that some folks stick to their sticky models.

 

27 minutes ago, Lima Hotel Foxtrot said:

That's their silly fault for not taking proper precautions. The plane is just an object, it's the user who makes the mistake.

 

Indeed. Even so, the thing that surprises me is the near continual stories you hear on forums people who have had electric models come to life and "surprise" them on turning on their radio or plugging in the battery; in the early days of electric that was definitely an issue, but it really shouldn't be the case now with modern ESCs.

 

I did some brief tests with my last TX when it was new (~8 or 9 years ago now), and even without any safety features set (e.g. a std or sticky throttle cut) I could not get any of the ESCs I tested to fire up the motor if I plugged in with the throttle above zero. A few went into programming mode and others beeped a lot without doing much at all, but none fired the motor. Not saying it isn't possible, just that all the (mainly Hobbywing, a couple of Horizon Hobby ones and a Hacker) ESCs I tested seemed to have inbuilt safety features that seem to mean they don't behave that way. I guess other ESCs out there are different...

 

ADDITION - I just rememenred that I have seen a model leap into life once in the recent past when the TX was switched on, but that was after the model had changed hands from a Spek to Futaba user. It was the classic "the throttle works the other way round on Futaba" issue. Caveat emptor!

 

 

Edited May 30, 2023 by MattyB

[GrumpyGnome]

Have to say I agree with MattyB.  I still take sensible precautions though....

[leccyflyer]

Like Matty said, inadvertent motor starts could be an issue years ago, when using brushed motors, which just need a voltage applied to their terminals to fire up. With brushless set-ups the motor requires current to be supplied by the ESC to each wind in turn for the motor to fire up and run. ESCs and radio systems are also more "intelligent" now, with more inbuilt safety features, such as detecting when the throttle is above minimum and issuing a warning, or indicating with a series of beeps that there is potentially a problem.

 

Following sound, logical, safety procedures makes electric flight every bit as safe as IC but there is no accounting for those whose operating procedures are sloppy or, for all of us, where an error is made which results in a propeller causing injury. That's why you must always take care around propellers and to stay out of their bite radius. We can all make mistakes but, in general when one does an assessment of an accident it's more often than not a fault of human error.

[leccyflyer]

One of the most obvious and frequent cause of near misses with electric flight is the inadvertent operation of the throttle stick when picking up, carrying or retrieving a model at the end of the flight. use of the readily available throttle cut on a switch is highly recommended to mitigate this risk, but that should also be accompanied by picking up the model in such a way that you aren't in danger of being clipped by the prop. You shouldn't need the noise of a running engine to make that an obvious point of risk management. You should also endeavour to disconnect the main flight battery at the earliest available opportunity at the end of the flight - there is no way you should ever be leaving models lying around with their power systems live.

[Paul De Tourtoulon]

2 hours ago, Lima Hotel Foxtrot said:

That's their silly fault for not taking proper precautions. The plane is just an object, it's the user who makes the mistake.

So you have Never made a mistake ?, never had an accident ?, the pylon racer was an electrical fault in the plane not pilot error, the battery is installed and the wing fitted, then the radio switched on ( no names ) and to fly a "U" electrical jumper is fitted to fly, it was at that moment the motor went flat out, lucky for him, I was holding his plane tightly on the table !, in fact he was the French champion a couple of years ago, and he knows what he is doing !.

Edited May 30, 2023 by Paul De Tourtoulon
sad,,,,

[leccyflyer]

10 minutes ago, Paul De Tourtoulon said:

So you have Never made a mistake ?, never had an accident ?, the pylon racer was an electrical fault in the plane not pilot error, the battery is installed and the wing fitted, then the radio switched on ( no names ) and to fly a "U" electrical jumper is fitted to fly, it was at that moment the motor went flat out, lucky for him, I was holding his plane tightly on the table !, in fact he was the French champion a couple of years ago, and he knows what he is doing !.

I'd be interested to know the nature of the electrical fault in the aeroplane, which might cause such an occurrence.

 

Where was the "jumper" fitted in the model? In the battery to ESC lead? What was the position of the throttle stick when that connection was made? Did he have a  Throttle Cut set on the transmitter for that  model? 

[MattyB]

1 hour ago, Paul De Tourtoulon said:

So you have Never made a mistake ?, never had an accident ?, the pylon racer was an electrical fault in the plane not pilot error, the battery is installed and the wing fitted, then the radio switched on ( no names ) and to fly a "U" electrical jumper is fitted to fly, it was at that moment the motor went flat out, lucky for him, I was holding his plane tightly on the table !, in fact he was the French champion a couple of years ago, and he knows what he is doing !.

 

Of course we have all made mistakes. The point is that if you have multiple procedural and technical controls in place no single mistake should result in an accident. That is exactly what happened in your example, and is exactly how safety relevent control systems in industrial systems, full size aviation etc are designed too.

 

Before plugging in the battery on any of my electric models, the following have all happened either on the day or back when I originally built and setup the model:

1. Powertrain fit-out (for any new or secondhand model) - I test any new ESCs on the bench before fitting them to a model to check if they will drive the motor if power is applied with the throttle signal above zero (literally none have failed this test this for about the last 6 or 7 years, but I still do it)
2. Original TX setup - I setup and tested a sticky throttle cut so that the throttle can only be enabled if the thottle stick is fully down AND the throttle is enabled via a switch (in some of my models that AND test requires two or more switches to be in the correct positions)
3. Original TX setup - I set audio warning on all my switch positions so that every time they move I get a call-out to tell me what has been switched on or off (including throttle cut switch)
4. Original TX setup - I enable switch position checks so that when I switch on the TX or select a new model the TX displays onscreen any switches not in the correct starting position, and won't let you mvoe forward until you've addressed those.
5. Pre-flight checks - I always turn on the TX first, validate model selected is correct and all switches are in the right positions (validated by 3 and 4 above). For the first flight of the day I also visually check on the outputs screen that the throttle output is behaving as expected based onthe position of the cut switch and throttle stick before powering up the model.
6. Physical safety - I tether the model wherever that is possible (I do have a couple of parkflyers where the battery is loaded from underneath and/or the tail type makes it difficult to do this, so they just get held firmly in the approiriate position by a helper or placed on the ground in such a way that the prop could not turn if the motor went live).
7. Physical safety - I only load and plug in the battery from behind the model, and only in the location mandated by the flying location (e.g not until you reach the flightline at one of my clubs, with the model pointed away).
8. Physical safety - If I can't taxi out for some reason (i.e. no wheels, or wheels too small for the length of grass) I will disable the throttle until a few seconds before take-off to ensure it can't be accidentally knocked as I walk the model out. If I'm not hand launching and there is someone else with me, I'll leave the TX with them in the pits (throttle disabled) whilst I walk the model to it's starting position.

Going back to your example, I fully agree that none of the above precautions could prevent an electrical fault in the plane occurring some time after the inital install (NB - Like Leccy I'd be intrigued to understand what it was;  if it had flown before without doing that it's hard to understand how such a situationcould occur, as ESCs don't spontaneously change behaviour without being reconfigured by a user...). However, if one or more of steps 2-5 had been implemented that would definitely have prevented the motor going live, because the ESC would never have seen a signal telling it to drive the motor. As it was you did not have an accident because you and your friend had applied 6 (and presumably 7?), so even when the model went live, it did not move forward or hit anyone.

 

QED - if you take multiple procedural and technical precautions to prevent a motor run-up, ALL of them have to fail in order for physical harm to occur.

 

Edited May 30, 2023 by MattyB

[MattyB]

PS - To pre-empt the (I suspect inevitable) "well that's a lot of faff" and/or "you don't need to do that for IC, electric is so complicated" response 😉, three things...

• All my TX setups are based on standard templates from previous models, so 2-4 in the list take no more than 3 mins to implement and check for each new model
• 5-8 are all pretty much straight out of the BMFA Handbook, with only 7 being electric specific - the others also apply to IC
• Even if you still think 1-5 are hard work, they definitely aren't compared to an 8hr trip to your average over-worked casualty department on a Sunday afternoon with a bloody towel around your hand...

 

PPS - If I look back, the rigour with which I check my model kit and setups is all routed in my (now somewhat distant) full size gliding experience. Anyone who has done full sized flying of any type will have had airframe walkarounds and multiple checklists drilled into them from day 1; I know this is part of the BMFA handbook, but I've only seen a handful of model flying instructors emphasise the pre-flight checks to a level that full size ones do. Yes it's a only a fun hobby for most of us, but having that extra bit of rigour when it comes to prepping your equipment, evaluating conditions and making as many critical decisions before take-off as you can is really helpful whn it comes to avoiding accidents of all types.

 

Edited May 30, 2023 by MattyB

[Lima Hotel Foxtrot]

1 hour ago, Paul De Tourtoulon said:

So you have Never made a mistake ?, never had an accident ?

Nope, not once. I'm perfect. 

[Learner]

5 minutes ago, MattyB said:

PS - To pre-empt the (I suspect inevitable) "well that's a lot of faff" and/or "you don't need to do that for IC, electiric is so complicated" response 😉, three things...

• All my TX setups are based on standard templates from previous models, so 2-4 in the list above takes no more than 3 mins to implement and check
• 5-8 are all pretty much straight out of the BMFA Handbook, with only 7 being electric specific - the others also apply to IC
• Even if you still think 1-5 are hard work, they definitely aren't compared to a trip to your average over-worked casualtydepartment  on a Sunday afternoon with a bloody towel around your hand...

 

Don't worry I was abrubtly told off for irrelevance to the op.

But although I agree safety is paramount apparently the teller off only reads selected posts and op wandering is allowed by some!

[John Lee]

I endorse all that Matty says and treat an armed electric model with the same respect that I do a circular saw.

 

[Paul De Tourtoulon]

Yes all those check-ups are good advice but 'beginners' don't do that, the number of Rc cars and those cheap twin rotor helicopters that have come into my shop with the battery still plugged in,,,

 

 We all have to start somewhere and that's what clubs are for, and no I am not perfect like some, I have arrived at the field without or with the wrong radio, on the wrong memory, especially with my T6 where you only have 4 letters on the screen to tell you what model it is, etc,,,,

[leccyflyer]

18 minutes ago, Paul De Tourtoulon said:

Yes all those check-ups are good advice but 'beginners' don't do that, the number of Rc cars and those cheap twin rotor helicopters that have come into my shop with the battery still plugged in,,,

 

 We all have to start somewhere and that's what clubs are for, and no I am not perfect like some, I have arrived at the field without or with the wrong radio, on the wrong memory, especially with my T6 where you only have 4 letters on the screen to tell you what model it is, etc,,,,

Did the French ex-Champion have the wrong model selected in his transmitter -with a reversed throttle set up -  was that the nature of the fault?

[Paul De Tourtoulon]

I have no idea, he was in 'racing' mode in the French championships, and it was his turn to race, I was his 'mechanic' and just followed his orders, I only race with those smelly, noisy, smothered with caster oil planes.

[MattyB]

2 hours ago, Paul De Tourtoulon said:

Yes all those check-ups are good advice but 'beginners' don't do that, the number of Rc cars and those cheap twin rotor helicopters that have come into my shop with the battery still plugged in...

 

We all have to start somewhere and that's what clubs are for...

 

I am a bit lost now. You called electric a "silent killer", and when challenged that such a statement was unhelpful responded with examples of accidents that are clearly down to poor practices by the individuals involved. When multiple posters point out that the errors that caased those incidents are eminently avoidable with a bit of thought and some sound handling practices (many of which are just as applicable to IC power), you respond with "...but beginners don't do that", and inform us that clubs are the answer (I assume based on the instruction a beginner would receive there).

 

Two questions...

• What different advice to that provided above (e.g. setup a throttle cut, use the functions in your TX to ensure the correct model is selected and switches are in the right positions, conduct pre-flight checks before powering up, tether your model, plug in the battery from behind the prop arc etc) do you believe a club instructor is going to give to a beginner starting out in electric flight? Aren't they just going pass on that same information on verbally and through demonstration, allowing the beginner to progress to become a confident and safe intermediate? And isn't a well proven way of doing that giving the student a checklist (ideally with a mnemonic) to remember?
• If electric power is dangerous, presumably you advocate all beginners start on IC as it is "lower risk"? Based on a quick count, 5 of the 8 safety bullets listed above are applicable to IC, but there are other risks not addressed there that a pilot needs to think about with IC that aren't applicable to electric (e.g. engine starting procedures, needle valve adjustment, safe storage and transportation of fuel, etc.). If instructors are to pass on information on those additional points effectively, aren't they going to have to teach the necessary practices using checklists exactly as you would with an electric aircraft?

Edited May 30, 2023 by MattyB

[MattyB]

2 hours ago, leccyflyer said:

Did the French ex-Champion have the wrong model selected in his transmitter -with a reversed throttle set up -  was that the nature of the fault?

 

Further up the page he was certain it was an electrical fault in the plane, but now he has no idea. Interesting.... 🤨

 

@Paul De Tourtoulon, I am only joshing, no hard feelings; I just don't think it is very helpful to throw in terms like "silent killer" when we all know it is not the power source that causes accidents, but poor practices. Electric or IC, both should be treated with respect and care, and both are perfectly capable of being operated very safely with the right knowledge.

Edited May 30, 2023 by MattyB

[Paul De Tourtoulon]

Come on matty use your common sense,

1, a howling IC engine is warning enough,

2,  the kickbacks when starting teaches you their danger, 

3, a beginner might only have a basic radio, so throttle lock might not be there

4,, he probably hasn't read the chinglese instructions, let alone understood them, 

5, how many times have you seen someone lean over the prop to plug or unplug the battery,

 

Don't be silly, IC is dangerous and electric is the best and safest way to start, but under guidance !!!!!

In 50 years of modelling I have NEVER had methanol or petrol catch fire, but 2 battery's, one on the model field and one in my garage,

 

 I wasn't certain of anything,  only surmising, as he has been flying electrics much more than me, and as I had never seen his set-up I was only guessing,,,

 

I know how it feels to flog a dead horse now,,,,🤐

 

Better things to do,,,

 

Here is one for my sceptic disbelievers, the second time that one of the wires on my battery's has broken, here a 4s on my big starter, ( electrics please look away😄) a mix of 30 minute epoxy with some fine aluminium filing has done the job again.

[leccyflyer]

Hang on a mo - buying the well know horrible Youme brand of batteries - which have definitely got a reputation - to use in an electric starter isn't anything to do with electric flight safety.

 

Sort of thing that might be expected when one gets one's batteries from The Chuckle Brothers though. 😉

[MattyB]

16 hours ago, Paul De Tourtoulon said:

Come on matty use your common sense,

1, a howling IC engine is warning enough,

2,  the kickbacks when starting teaches you their danger, 

3, a beginner might only have a basic radio, so throttle lock might not be there

4,, he probably hasn't read the chinglese instructions, let alone understood them, 

5, how many times have you seen someone lean over the prop to plug or unplug the battery,

 

Don't be silly, IC is dangerous and electric is the best and safest way to start, but under guidance !!!!!

In 50 years of modelling I have NEVER had methanol or petrol catch fire, but 2 battery's, one on the model field and one in my garage,

 

 I wasn't certain of anything,  only surmising, as he has been flying electrics much more than me, and as I had never seen his set-up I was only guessing,,,

 

I'm sure you have a point (or several) in there somewhere, but I guess I don't have sufficient IC expereince and/or I'm not bright enough to understand them, sorry. Time to check out; as you say, we are well OT at this point.

 

One final point though... Somewhere along the line you seem to have come to the conclusion that indivudals posting in this thread have suggested beginners should go it alone without instruction, but I don't believe anyone said that. All I posted was a list of safe practices for electric flying, 95% of which I have been taught or read up on, with another 5% my own refinements (mostly as new tech has become available to help). Neither I nor anyone else were espousing replacing an instructor with a checklist, only that a list similar to that is exactly what any instructor is going using with a beginner. For that reason dismissing the list with "Yes all those check-ups are good advice but 'beginners' don't do that..." is rather strange - after all, checklists are an almost universal tool for instruction, irrelevent of the power source chosen.