Lee Smalley Posted June 27, 2011 Share Posted June 27, 2011 some months ago i bought some replacement packs from the component shop 6v eneloop 2200 mah, one was installed (wrapped in foam) in my Zlin 50L review model, on about the 6th flight 2 points into a 4 point roll, nothing .....model carried on rolling and impacted in the next feild lost my engine badly damaged (damn it loved that engine) some servos and obviously a very very nice aeroplane that i had very high hopes for, after a careful diagnosis it came back to the new pack as you can see the positive wire has been directly soldered onto the cell, not a great idea, and there is absolutly no support to the wire (unlike the negative wire, which has been soldered onto a tag and has heat shrink on) this in my opinion is very very poor sadly it was covered over by the paper on top of the cels so i never knew it was made like this, i would suggest you check your packs carefully from this supplier (my other is the same) and i have sent an email to them for their comments regards Lee !! Quote Link to comment Share on other sites More sharing options...
Lee Smalley Posted June 27, 2011 Author Share Posted June 27, 2011 the results Quote Link to comment Share on other sites More sharing options...
Ben B Posted June 27, 2011 Share Posted June 27, 2011 Yes, good point. It would have been better if they had looped the red wire under the heat shrink to give some kind of strain relief, but it's not ideal. For one thing I don't think the end of the cell is designed to be used as a solder tab! For one thing the emergency vent is under the cap and that getting bunged with solder might be bad! Quote Link to comment Share on other sites More sharing options...
Steve W-O Posted June 27, 2011 Share Posted June 27, 2011 I think it is very disappointing, approaching disgraceful, for a commercial concern to construct a battery pack in that way. The general advice by battery manufacturers has always been not to to solder directly to the battery (don't say we always follow that advice) Any half decent pack manufacturer would have the means to spot weld tags on to the battery, so that the wires can be soldered onto the welded tags. After all, if it is only soldered, what are you paying for? It also looks like it was never soldered properly in the first place, if it was, it would not come off so easily, so very poor show all round. Certainly worth avoiding them in future. Edited By Steve W-O on 27/06/2011 14:44:09 Quote Link to comment Share on other sites More sharing options...
Snorbitz Posted June 27, 2011 Share Posted June 27, 2011 Having just wrapped my new battery deep in some foam (same supplier/same battery) and installed it into a newly rebuilt warbird i'm now very nervous. I wil be taking it back out...sigh....and checking to see if its up to a decent standard. And people wonder why we don't shop in the UK. We do it to ourselves don't we. Cheers for the heads-up Lee. Plz keep us posted on the reply from "the shop". Edited By Shuglu on 27/06/2011 13:34:14 Quote Link to comment Share on other sites More sharing options...
Lee Smalley Posted June 27, 2011 Author Share Posted June 27, 2011 i can't understand why the negative cell has a tag welded on and yet the positive does not, its very strange, i have emailed the company i bought them from for there comments, i do not yet know if the packs are made there or externally and then bought in !! Quote Link to comment Share on other sites More sharing options...
Lee Smalley Posted June 27, 2011 Author Share Posted June 27, 2011 sorry for that shuglu, but better safe than sorry especially if its IC mate!! still gutted lost my ultra reliable ASP 108, man that thing never stopped even when out of fuel !!! loved it !!! gutted Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted June 27, 2011 Share Posted June 27, 2011 Ben, modellers have been making up packs by soldering to the end-caps since the cells first appeared, it shouldn't be a problem. I've seen plenty of packs with poorly welded tags, so I don't think that's a complete answer either. You are spot on regarding the lack of support. Steve, the packs are welded together, but you can't weld copper to nickel (the end caps), so the wires have to be soldered. This can be done either direct to the cap or via a welded tag, to me soldering to a welded tag just adds an extra point of failure.It's the lack of support for the cable that is scary, even if the soldered joint is good, you have a stress point at the end of the soldered section of wire, which needs support - see the Vapextech thread.Lee, did the wire fracture leaving the end in the soldered joint, or did the soldered joint separate leaving the wire intact? From what I can see in the photo it looks to be a fracture at the end of the soldered area, which is pure bad design of the pack. Quote Link to comment Share on other sites More sharing options...
Snorbitz Posted June 27, 2011 Share Posted June 27, 2011 I think that if the wire needs some support i'll be putting a loop into the wire under some fresh heatshrink and potting it up to support it further. Mine are to be used in a 26cc petrol where vibration is a killer for anything like that. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted June 27, 2011 Share Posted June 27, 2011 Here's an old Vapextech LSD pack that I'd just binned. Note that they use welded tags, but still next to no support for the cable. Quote Link to comment Share on other sites More sharing options...
Lee Smalley Posted June 27, 2011 Author Share Posted June 27, 2011 and yet my vapex packs look nowt like that!!! where was it bought from bob! Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted June 27, 2011 Share Posted June 27, 2011 Darn it Lee, annoying isn't the word.....it's a good 'heads up' but not the way anyone wants to discover these things. Edited By David Ashby - RCME Administrator on 27/06/2011 14:04:27 Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted June 27, 2011 Share Posted June 27, 2011 Posted by Bob Cotsford on 27/06/2011 13:43:48:Ben, modellers have been making up packs by soldering to the end-caps since the cells first appeared, it shouldn't be a problem. I've seen plenty of packs with poorly welded tags, so I don't think that's a complete answer either. You are spot on regarding the lack of support. Steve, the packs are welded together, but you can't weld copper to nickel (the end caps), so the wires have to be soldered. This can be done either direct to the cap or via a welded tag, to me soldering to a welded tag just adds an extra point of failure.It's the lack of support for the cable that is scary, even if the soldered joint is good, you have a stress point at the end of the soldered section of wire, which needs support - see the Vapextech thread.Lee, did the wire fracture leaving the end in the soldered joint, or did the soldered joint separate leaving the wire intact? From what I can see in the photo it looks to be a fracture at the end of the soldered area, which is pure bad design of the pack. Correct - soldering directly to the end caps, and end-to-end soldering has been used with complete success for many years with NiCds and Nimhs. The same criteria, regarding support, apply to the solder joint between the wire and welded-on tag as between the wire and the end button. Both require proper support. Quote Link to comment Share on other sites More sharing options...
Steve W-O Posted June 27, 2011 Share Posted June 27, 2011 Posted by Bob Cotsford on 27/06/2011 13:43:48:Ben, modellers have been making up packs by soldering to the end-caps since the cells first appeared, it shouldn't be a problem. I've seen plenty of packs with poorly welded tags, so I don't think that's a complete answer either. You are spot on regarding the lack of support. Steve, the packs are welded together, but you can't weld copper to nickel (the end caps), so the wires have to be soldered. This can be done either direct to the cap or via a welded tag, to me soldering to a welded tag just adds an extra point of failure.It's the lack of support for the cable that is scary, even if the soldered joint is good, you have a stress point at the end of the soldered section of wire, which needs support - see the Vapextech thread.Lee, did the wire fracture leaving the end in the soldered joint, or did the soldered joint separate leaving the wire intact? From what I can see in the photo it looks to be a fracture at the end of the soldered area, which is pure bad design of the pack. I didn't suggest welding "copper to nickel", I've added the words "so that the wires can be soldered onto the welded tags" to make my post clearer. The end caps are usually steel, which means soldering has to be done well. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted June 27, 2011 Share Posted June 27, 2011 Lee, I'm pretty sure that pack came from ComponentShop Here's a flat eneloop, it's brand new arrived on Saturday: No support at all, just like yours. A blob of Evostic first to secure against vibration then a good layer of rescue tape secures the cable down the side to guard against direct stress on the joint. Again, thanks for the heads-up Lee, I'm a lot happier now I've secured the cables, it's just a pity you had to find out about the problem the hard way. Edited By Bob Cotsford on 27/06/2011 15:01:10 Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted June 27, 2011 Share Posted June 27, 2011 Posted by Steve W-O on 27/06/2011 14:47:22: I didn't suggest welding "copper to nickel", I've added the words "so that the wires can be soldered onto the welded tags" to make my post clearer. The end caps are usually steel, which means soldering has to be done well. Sorry Steve, I didn't mean to imply that you thought otherwise, I was trying to make the point that soldering to a tag adds an extra potential failure point. I've had the tags break away with the wire still attached in the past. Edited By Bob Cotsford on 27/06/2011 15:05:54how odd - it wouldn't let me type outside the quoted text! Edited By Bob Cotsford on 27/06/2011 15:06:30 Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted June 27, 2011 Share Posted June 27, 2011 You needed a welded quote tag to solder onto Bob..... I've seen welded tags from mainstream pack manufacturers where only one of the spot welds was still in contact. The tag could easily be pulled off the endcap. Mind you I've also seen a pack from a mainstream manufacturer where only the heatshrink was holding the wire onto the tag, the dry joint having given up the ghost long ago. Quote Link to comment Share on other sites More sharing options...
Peter Beeney Posted June 27, 2011 Share Posted June 27, 2011 Lee, Just to qualify exactly what you’ve said, here’s another a couple of photos of a pack that I’m checking out at the moment. This was given to me by a fellow club member, which he said he bought new but his charger didn’t seem to like it. The first thing I must say is that I don’t know where he bought it, unlikely from Component Shop, but they may be assembled by Vapextech anyway. Here the short wire is the neg, a total lack of support again, and both are soldered to tags. Judging from the rust evidence on the positive end, that looks to be have been slowly developing for a long time, the pack is much older than we though it was. I’ve seen similar on very old nicads, but they were still supplying the full whack of watts! I must stress again, though, I’ve no idea how old it is. A wire soldered to a tag, terminal, cell or whatever, if unsupported and subjected to any vibration, will break just where the solder finishes. Even when soldered to itself and given a straight pull, strong enough to beak it. Something to do with mechanics, the fulcrum point, I guess.I’ve been inspecting packs for years, and it’s certainly possible that the standards are dropping, although there has always been the odd example that really make you look again. As I’ve said many times, it’s a consumer market. Who is answerable for what? I’ve also rewired many packs, when there is any evidence of black wire corrosion, and even if the inter cell connections are spot welded, the wires are always soldered.I’ve also been trying to raise these many many battery issues for a lifetime now, with letters to the various supplies (including Component Shop!), and the BMFA, to no avail, but maybe if there were a few raised voices in concert someone might actually notice. Whilst I never like to see or hear of a crashed model, I know the feeling, but I’m far more concerned about where it crashes. When the servos suddenly stop a model can fly quite a long way, and from recent experience it can finish up very close to other flyers; and it happens in the blink of an eye, before anyone can move. I’d just started to fiddle with this pack, it was showing signs of a high internal resistance. I may have found the reason. Before I cut the insulation it certainly looked like a reasonably new lump! Having said all of the above, I’m sure that batteries that are in good nick, and that includes the peripherals - wiring etc. are still considered the most reliable form of energy supply. They are at the end of any no-break emergency system.PB Quote Link to comment Share on other sites More sharing options...
Lee Smalley Posted June 27, 2011 Author Share Posted June 27, 2011 This thread is getting quite scary! Yes the lead did fail just as the wire came out of the solder, the wire has fractured. I have suspicions that packs are made from various places the cell manufacturers sell the cells such as sanyo vapex, and then these are made up by a second party into packs, this would explain the varying quality of construction, on the soldering directly onto cells, I am not a great lover of it, this method introduces large amounts of heat directly to the cell for a prolonged period of time, that spot welding does not, especially if done badly, but ultimately support is the key, I will be checking all my packs tonight and if I get a reply from the component shop I will let you all know Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted June 27, 2011 Share Posted June 27, 2011 Posted by Lee Smalley on 27/06/2011 16:06:36:This thread is getting quite scary! Yes the lead did fail just as the wire came out of the solder, the wire has fractured. I have suspicions that packs are made from various places the cell manufacturers sell the cells such as sanyo vapex, and then these are made up by a second party into packs, this would explain the varying quality of construction, on the soldering directly onto cells, I am not a great lover of it, this method introduces large amounts of heat directly to the cell for a prolonged period of time, that spot welding does not, especially if done badly, but ultimately support is the key, I will be checking all my packs tonight and if I get a reply from the component shop I will let you all know Actually the only time that soldering directly to the can would introduce large amounts of heat directly to the can for long periods would be if the person doing the job did not know what they were doing. Large iron, scrupulously clean workpieces, pre-tinning and a very quick touch is all that is required for a proper job. If the person doing the job cannot manage that, then the chances are that they would be putting a lot of heat, for a long time onto the tag, and therefore right onto the cell itself, anyway. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 27, 2011 Share Posted June 27, 2011 Exactly right LF .The "secret" is a HOT iron, with a LARGE tip to hold the heat. I have been soldering wire to cell ends like this for donkeys years - we never had the "luxury" of tags, and the A123 cells have no tags either, and large surface areas to solder to also.Light sanding with a fine dremel drum, clean with IPA, no touching with fingers etc, and well tinned joint - bingo. In the bad old pre-lipo days, all our flight packs were from sub C cells or larger, no tags, and special jigs were available to hold the cells for end to end soldering of the"sticks". Cable retention / strain relief is the issue in this case, which I accomplish with a dab of hot glue or two. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 27, 2011 Share Posted June 27, 2011 Not my picture, but this shows what I mean - note the large hammerhead iron, I still have mine and use it frequently for such work. Puffin models amongst others stock them. Quote Link to comment Share on other sites More sharing options...
Josip Vrandecic -Mes Posted June 27, 2011 Share Posted June 27, 2011 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 Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 27, 2011 Share Posted June 27, 2011 I may be wrong - but I think battery boxes are "forbidden" for airborne packs under BMFA guidelines. EDIT: Found it....Page 23. Edited By Tim Mackey - Administrator on 27/06/2011 19:45:17 Quote Link to comment Share on other sites More sharing options...
Ultymate Posted June 27, 2011 Share Posted June 27, 2011 I always tape the wires on to outside of the pack making sure to leave a little slack so that no pull or vibration is transmitted to the wire or soldered joint. Copper cored wire work hardens and breaks very easily as Tim has already intimated. Sorry for your loss though Lee Quote Link to comment Share on other sites More sharing options...
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