Model lost from faulty pack

[Martin Harris - Moderator]

I don't think you are, Timbo

 

They quote factors such as vibration and high current capabilities in the handbook.

[Josip Vrandecic -Mes]

Hi Tim , all my battery and containers, I bought in Germany and Austria,where this is allowed.....such package are easier to modify and control the voltage (each battery separately) , of course, by solid bandage...

Cheers Jo

 

Edited By Josip Vrandecic -Mess on 27/06/2011 20:55:31

[Lee Smalley]

Right I have had a look at most of my packs and it's a bit of an eye opener, I have packs made or bought from the same supplier have wildly differing standards of build, some are well done with wires supported etc yet with others being poorly supported the only ones that seem to be consistent are the recent ones I bought from vapextech they have been very well made with the wires supported the entire length of the pack, so I will be doing the following all packs I purchase in the future will be checked when I recieve them and amendments made straight away, when I find a supplier who consistently supplies well constructed I will stick with them, at the moment this is vapextech, if I get a response from component shop I will let you all know

[leccyflyer]

Posted by Josip Vrandecic -Mess on 27/06/2011 19:26:36:

Good evening Lee , my recommendation is NO SOLDERING ,so avoid a touch of hot soldering iron,I use battery container.....so far proved to be reliable.

Cheers Jo

Does it come with a 12 foot bargepole?

 

Sorry Jo, those things really are an accident waiting to happen and to be avoided at all costs.

 

 

[Peter Beeney]

I, too, would consider there are no real problems with soldered cells. One way of doing it may be this.

Use good quality, brand name cells in the first instance and test them individually before gluing them together. For the joiner link use 1mm solid copper wire as used in 1mm T&E (Twin and Earth) household wiring. It’s very clean and solders perfectly, as do the ends of the cell. Also it may very advisable to enlist the assistance of some Powerflow flux here, it really does make a difference, even when using multi-core solder. Another advantage, you can configure the pack as you want it. The 1mm wire is not only a very low impedance conductor, helping to keep the total pack resistance low, it also makes a very rigid secure arrangement of the joined up cells, you’d probably have to hit it with a hammer to break it. Clean off any flux residue while it’s still warm and lay a small piece of card across the joins, to prevent the connector wire laying again the bare metal, make both ends face inwards and double the wire back, for total strain relief, tape it well over with a couple of layers of masking tape, followed by a layer of insulating tape. A test discharge to establish the capacity, write this result and the date on a label and plonk it on. Then I often solder this chunk to the switch harness but if you use the plug and socket make sure they are well secured together in some way. These can come undone, sometimes with embarrassing results. Then fly in the full confidence that this will never give a moments trouble. Use an on board monitor to be able to always check that you have enough battery capacity for the next flight; in my view this is as important as checking the controls for correct operation, get either wrong and they will both cause an instant out-of-control crash, guaranteed, even I’d bet money on it, ‘cos both have definitely happened; and do a total capacity check from time to time - annually, say. Then you you will only have to do this trick very infrequently, they can last a long time. I can say that with the assurance some personal experience.

When I first started out a soldering iron was a lump of copper fixed on the end of a metal rod which in turn had a wooden handle which looked as if it were a piece of sawn-off broom handle. It was the official supplied item though, and was for use out in the sticks miles from any electricity supply. It was heated frequently by the ubiquitous propane stove, whilst simultaneously boiling the tea kettle. The greenish tinge of hot copper in the flame was the indicator that we were ready to start. With a bit of re-shaping, this made an ideal tool for end-to-end nickel flight packs, I made a little jig for this. I always used silver loaded solder, from Radio Shack. Worked a treat!

We also had a personal issue of a piece of Safety Equipment, many of these used the spring loaded battery carrier as mentioned by Josip. These suffered a hard life, from bursts of hard rough treatment to long periods of non-usage when not required. They used primary cells, that’s dry batteries to you and me, and I never heard of any cases where these carriers gave any trouble at all. Of course, the cells would go flat over time, and always exactly at the one moment you didn’t have any spares! In fact, there are many devices that use a spring load battery holder, the Spektrum DX5e tx for one, but how often is this an issue? When you spin the cells in the tv remote to wake it up I think this is an indicator that the voltage is beginning to fail, rather than the cell connection becoming weak or fragile.

I’m sure these carriers are much more reliable than they are given credit for, however, I must say that just looking of them does not inspire great confidence. But I would be quite happy to use one in a model.

 

PS We’ve found it’s the switch that can be at fault in the DX5e, not the battery compartment!

PB

[Ben B]

Posted by leccyflyer on 27/06/2011 22:41:40:

Posted by Josip Vrandecic -Mess on 27/06/2011 19:26:36:

Good evening Lee , my recommendation is NO SOLDERING ,so avoid a touch of hot soldering iron,I use battery container.....so far proved to be reliable.

Cheers Jo

Does it come with a 12 foot bargepole?

 

Sorry Jo, those things really are an accident waiting to happen and to be avoided at all costs.

 

 

Absolutely- way too points of failure. They have a total of eight contacts waiting to become lose / snap / rust etc etc.

[Vecchio Austriaco]

I used the battery boxes as mentioed by Jo in all my glider models when i flew in Austria in the 80th - no error - neither on my stuff nor on that of my mates. May be a more philosophic question.

If somebody doesn't remove the flux properly I personally prefer the sprung contacts against slowly corroding solderd connections.

Greetings from the Old Austrian

Edited By Vecchio Austriaco on 28/06/2011 15:17:37

[Lee Smalley]

not using one of them on my 30cc superstar!! it can shake the filling loose in your teeth that puppy

[Bob Cotsford]

too many memories of struggling to get pushbike lamps to work for me to rely on sprung contacts. They are not recommended by the BMFA for good reason.

They may work most of the time, but then I rode big motorbikes far too fast for far too many years, I never came a real cropper, but that doesn't help those less lucky than me!

[Snorbitz]

Any news back from the Component shop yet Lee?

I've reworked the ones i have by cutting the heatshrink back a bit and looping the wire back on itself before potting it and then some fresh heatshrink over the top. I'm just checking the 3700mah sub C pack i got from there a while back and its the same i'm afraid to say. NOT HAPPY!! Thank god thats not been up in the sky either!!

[Lee Smalley]

Hi Shuglu, i wanted to give them some real time, but as of yet i have not even had a response to say "we are looking into it " nothing not a word, i am very dissapointed in the lack of response and also the variation of manufacture from their packs, only the packs bought from overlander or vapextech have been consistant in their construction, in theory i should be able to sue the company for faulty goods but lets face it, thats not going to happen, all i can do is vote with my feet and my wallet and buy from elsewhere .

 

from personal standpoint i will not be going anywhere near Component Shop and i certainly will never buy anything from Component Shop again, thats all i can do!!!

 

 

 

 

[Snorbitz]

I'll not be buying from them again either and all i can do is recommend others be careful if they do buy from this source. Shame really as i was trying to support a British supplier. We do it to ourselves don't we.

[Lee Smalley]

it seems so!!

 

anyway here is how she did look

[Peter Beeney]

I’ve used those AA and AAA battery carriers for testing purposes, that’s the cells, not the carriers, and they certainly seem very robust; and I’d consider this type to be easily quite capable of coping with any flight loads, in my opinion that’s not always the case with some other recommended equipment! I’ve done some slight mods on them, so I always tend to use the same ones over again. When on one occasion I was concerned about the very poor quality of some cells I emailed the supplier and when he replied he said, naturally enough, it was amongst other things my use of the carriers, plus the volts drop across the carrier contacts etc. that was at fault. When I explained that I’d drilled holes in the ends so that I could touch the volt meter test probes directly on to the ends of the cells, I am testing the battery, not the carrier, after all, plus some other procedures, I described everything in full, he decided not to communicate any more. Still, at least he answered once, no one else has ever even done that before.

Looking at Josip’s picture, I would personally sooner use that arrangement 100% in preference to some others. For a start, you can use the branded type cells you want to use, one of my primary requirements. I suspect that in his case the cable is soldered on, too, and also has adequate stain relief. A perfect job! With that wrapping on I’d certainly consider the pack would withstand any vibration test you could give it, even if it were done annually, certainly for the life of the cells. It would be worth a try without the wrapping, even! I’m not sure that the same could be said for many other soldered jobbies, a quick glance just at the top of this thread alone would seem to confirm that.

Maybe the BMFA should consider re-wording their recommendations, such as, ‘ Whatever type of battery system you use, please make sure it is fit for purpose’. After all, one of the only two statutory requirement governing aeromodelling actives says “ A person must not recklessly or negligently cause or permit an aircraft to endanger any person or property”. Very unlikely to ever be called into question, I must admit, but in these days of ‘litigate everything, and everyone!’ you never do know.

One other tiny rider here, too. I know of one definite case where the welded joining strip had not been done properly, the tag was not attached to the cell and the contact was being held together by the wrapping heatshrink. I’ve also seen that flagged up by another person, so it’s not a one-off. If that became an intermittent open circuit (very easily, I reckon) it could become a real head-scratcher! At least until you substituted another battery. No wonder I’m bald; and how would that fare in a Beach Boys Good Vibrations test?

Lee, I suspect that no one answers any letters and emails because they don’t have a really satisfactory explanation to start with, but more importantly if they reply they are admitting to being aware of your communication; and then by default, having to admit they were aware of a potential problem in any future incident etc. Plus the fact that it’s very cheap and easy not to reply.

For the record, there is a volts drop across the carrier under a reasonably hefty load, that is inevitable, but it’s no more than you’d expect. Under flight conditions it would be negligible.

Look after your pack with plenty of TLC!!

PB

[Steve Hargreaves - Moderator]

Just joining this thread so I can see the outcome.....

 

I did have an issue with Component Shop earlier this year & getting a straight answer out of them was like pulling teeth. We got there in the end but it was worse than dealing with BT & that's saying something!!!

 

I should add that I have had a few batteries & such like off them & found them generally to be pretty good....

 

Lee, I've PM'd you the details of the guy I was dealing with....I think he's one of the directors who set the company up....might save you driving to Bangor & camping outside...

[Steve Hargreaves - Moderator]

Or I would if Lee had a Public Profile...

[Josip Vrandecic -Mes]

Hi,Mr. Peter Beeney ,You have just convinced me to stay with my (Graupner) solution.

All coments and problems,I've see ,so far,relate to the sealed battery packs,from less known manufacturers and some od them even NO NAME.

I would like to add something about the battery box system:Every each unit (box) must be protected by high quality rubber band.This is for compactness and moisture protection.

Your efforts (extensive post ) deserves an honest answer.

Thanks for your time ...all the best

Jo.

[Steve W-O]

I must say I find it quite amusing that it can be suggested, in essence, that people people should take more care of and carry out more checks on their batteries, and then say that battery boxes relying on spring contacts are OK, as it adds another area that needs good care.

 

The whole idea of properly constructed packs is to eliminate an area of human error. you can't surely use the poor quality of manufacture to discredit the basic idea?

 

The number of times I have had to repair devices that don't work because of bad battery connections is huge.

[Lee Smalley]

was not aware i did not have a public profile!!! are you sure you can't pm me !!!?

 

to be honest Steve i have gave up on them, i will just vote with my wallet!!

[Steve Hargreaves - Moderator]

Well if I click on your name (Beereycalfs...wots that about then!!!) it just says you don't have a public profile....I suppose you need to keep the groupies away being a superstar RCM&E reviewer!!!

I know what you mean.....it is a bit like pulling teeth ....but this means they get away with it & continue supplying dodgy packs.....I really don't understand why suppliers bury their heads in the sand like this....if there's a problem...sort it fix it & move on.....how hard can it be...we all have to learn!!

[Tim Mackey]

You can still PM - just use "message member" button

[Peter Beeney]

Josip - Thanks for your reply.

Steve W-O

Yes, I think you’ve hit the nail right on the head! Properly constructed packs really are the operative words here. For myself, I would consider this actually means properly constructed packs, as I said, I’d choose some known good cells for a start and then hold them together in such a manner that they cannot, unless under some sort of extreme abnormal circumstance, come apart.

There must be millions of electrical contrivances, or perhaps even many more than that, that rely on the integrity of spring pressure for their successful operation. Such as switches, relay contacts, contactors, fuse holders, some of these in life or death situations, even. Even the humble domestic light bulb holder used spring loaded prongs, how great are just these items in number?. Consider all the little tiddly tykes, such as watches, with button cells; very low voltage and just enough current to wet the spring contacts. I don’t have a mob, so I’ve no knowledge, but I really can’t believe 76 million (UK alone, with a total population of 62 million*?!*??) are all hard-wired in. Of course not all the systems are perfect, but in the main very reliable, I would consider anyway. And some operate in rather more severe conditions than model aeroplanes.

The carriers I use are bog standard types, from Maplins, I personally think they are up to the job. Loaded with 4 cells and the cable soldered to the press stud connection, (that’s just a little tricky), and well supported, I think you you’d have to work extremely hard indeed to make this pack go open circuit. Whereas with some “properly constructed packs” it seems that exactly the opposite may be true. For me it would be infinitely preferable to use the known battery box; however, that is my personal choice and other aeromodellers will use exactly what ever they want to use. As I said, I only use these for the convenience of testing, and as I pointed out to the supplier, it enables me to easily test individual cells at the cell case, thus getting as near as possible the true conditions of charge and discharge.

I’m sorry if I appeared to be discredit the idea of soldered or welded packs, I would certainly not want to do that! What I can say is that I would use my own lash-up, however crude, rather than use a pack that might potentially let me down.

You mention repairing faulty items because of the battery connection, is that a repair to the item, or the battery connection? I’m not quite sure. Whilst there may be number of these, but I must admit that that I’ve not particularly noticed them, there must be a vast number that are trouble free.

Having said all the above, I’ve noticed that generally what ever you say it makes very little difference anyway. I don’t suppose anything is ever going to change.

PB

[Tim Mackey]

But all this still doesnt change the BMFA stance on things - spring loaded battery boxes are not recommended for onboard radio supply.

If a model crashed and claim was submitted, I doubt they would co-operate.

[Lee Smalley]

Hi steve yeah i have to beat them off with a stick !!!! not !! as my work mates keep telling me, im famous in sad circles !!! Beereycalfs came about when i used to drink too much beer and i have unfeasibly large calfs, i got called it once and that was it name stuck !!

i have tried to enable public profile but it just keeps asking me to change my nickname, anyway pm me the members way if you need owt!

as for the battery box debate i have to side with our tim here, your insurance could rest on the packs you use so i will always use welded packs, although as some have already stated i dont think that a properly constructed pack is anymore or less problematic than a well assembled pack using carriers, its just that i can't be bothered to make them up, especially when vapextech and overlander packs are 12 quid or so

 

many years ago my wife to be bought me a very small rx pack 4.8 volt 250mah, i think it cost her 40 quid or so in them days, he he!!

[Peter Beeney]

I’m not advocating the use of battery boxes for model use, just simply saying that I would consider that such an item would certainly be as good as a properly constructed pack; and I’m in no doubt whatsoever that a poorly constructed pack can at the very least prove to be very expensive indeed.
I think that anyone could browse this forum and possibly others, and realise there might be a bit of a problem with batteries in general; although I don’t really know about other forums as I don’t read any others.

If there were any battery incidents that warranted any investigation it might well include researching the records such as this forum. I think I might consider there is no shortage of evidence that models crash because of a lack of power, in it’s many varied guises; and how many of them would be considered unavoidable? And it’s possible that perhaps someone might consider that if this much is being recorded, just how much in total never gets a mention?

But… …as I said, I’m just as equally convinced than none of this will ever make any difference. We will all go merrily on our way until the next time, when the cycle starts again.

PB

Edited By Peter Beeney on 01/07/2011 20:36:55