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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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I recently replaced one of the two dead Ryobi 14.4v batt packs which
several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? TIA. ================================================== ============ Like peace and quiet? Buy a phoneless cord. http://www/diversify.com/stees.html Hilarious T-shirts online ================================================== ============ |
#2
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Larry Jaques wrote:
I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? It appears that spotwelding is the method of choice for attaching tabs to nicads. Spotwelding is normally done with, um, a spotwelder. - GWE |
#3
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Bah, freeze the cells then do a quicky with a good soldering iron- usually
does the deed without damaging the vent plastic on the top (+) of the cell.- did the same for a bunch of makita 9.6 stick packs/a drill master 12 v battery (2 of them) and a 9.6 black and decker. Can get the cells pretty reasonably at batteryspace.com or american scientific had some 6v-sub c packs for sale pretty cheap- but used. Pat |
#4
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It's not a good idea to build NiCd packs using cells from different
lots, or to mix used cells with new ones. If one of the cells is under-capacity versus the rest, it will go into reversal during discharge. Larry Jaques wrote: I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? TIA. ================================================== ============ Like peace and quiet? Buy a phoneless cord. http://www/diversify.com/stees.html Hilarious T-shirts online ================================================== ============ |
#5
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Larry Jaques wrote:
I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? TIA. ================================================== ============ Like peace and quiet? Buy a phoneless cord. http://www/diversify.com/stees.html Hilarious T-shirts online ================================================== ============ I usually buy cells with solder tabs already spot welded on them, but in a pinch I've used silver bearing conductive epoxy with excellent results. The stuff isn't cheap, but a little goes a long way, and you can store it forever in the kitchen freezer. I've never felt good about soldering directly to battery cells except for the old LeClanche carbon-zinc ones, back in the days when most of the commercially available (greater than 1.5 volt) dry cell batteries had their individual cells connected together by bare wire soldered to the zinc cans and brass carbon rod contacts. Happy Holidays, Jeff -- Jeffry Wisnia (W1BSV + Brass Rat '57 EE) "As long as there are final exams, there will be prayer in public schools" |
#6
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![]() Tim Killian wrote in message ... It's not a good idea to build NiCd packs using cells from different lots, or to mix used cells with new ones. If one of the cells is under-capacity versus the rest, it will go into reversal during discharge. Ok, he's got a dead pack(s). If he does put them back together and he gets one cell that calls it quits, where's he out worse than he was (is?) OTOH if he manages to good a viable pack that gets him further down the road for a little sweat equity....cool. Pat |
#7
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Larry Jaques wrote:
I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? If the cells are that old they're all at end-of-life anyway. Buy all new cells and build your own pack. Batteries America will cell you sells (?). -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
#8
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On Sat, 11 Dec 2004 08:51:18 -0800, Grant Erwin
calmly ranted: Larry Jaques wrote: I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? It appears that spotwelding is the method of choice for attaching tabs to nicads. Spotwelding is normally done with, um, a spotwelder. - GWE Everybody needs a little ass, but nobody needs a smart ass. ![]() OK, for the literalists: I don't have a spot welder. What do you suggest I use? ================================================== ============ Like peace and quiet? Buy a phoneless cord. http://www/diversify.com/stees.html Hilarious T-shirts online ================================================== ============ |
#9
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Larry Jaques wrote:
I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? I've never _re_built packs, but I have soldered them together. The best way I know is to use a hot hammerhead iron - that's a soldering iron with a bit with two working ends, so you heat both cells at once. The bit is about 1 inch long and 1/2 inch diameter, and looks like this: | iron | || | ___||___ | _/ \_ | |_ bit _| | \________/ | I have turned a few from copper, it's not hard - unfortunately I don't have any now, and I can't get back to the shop before mid-Jan (long holidays!). You really need at least a 40 watt iron, although it can be done with a smaller one. Wait for it to get hot People who make up a lot of packs tend to put the cells in the fridge before soldering, use 60/40 tin/lead solder rather than the leadfree type (naughty, but then the cells are full of cadmium ...), and make up a frame so the cells slide easily into the right position. You heat up the ends of two cells at once, make sure they are wet with solder, remove the iron and quickly slide one cell to meet the other. Then cover with heatshrink for mechanical strength. Never had a problem once I figured out how to do it - and you could of course practice with the hootered cells first. It might be worth while googling "hammerhead soldering cell" , some good links there. Below is a post I wrote in answer to a similar question, not an immediate answer but should have some relevant tips. However, Tim's point about reversal during discharge sounds relevant. I've always been a good boy and never tried mixing cells tho'. Perhaps you could try to find the set of cells whose capacities match best. -- Peter Fairbrother Hawkey wrote: Sh*T u aint kidding...30 odd pounds just for the bit!! I think I will forget it. thanks anyway ;-) Presuming you want to use it to end-to-end solder a few battery packs, why not just get a lump of copper, shape it, stick it on the end of an existing bit, preferably a worn-out one, and use that? You could use tap-and-die to thread it, or hard solder/braze, or just drill an undersized hole and hammer it together, whatever seems appropriate and available to attach the lump of copper. Should be almost free. Shape. Shape it like the bits you see in photographs, either with the ends like the end of a flat screwdriver with the tip cut off, or with the ends round with an extra lump in the middle between the ends. The cross section area at the middle should be about 3x the area of the working ends. The bulk of the metal holds the heat, and you want a good but not too good thermal transfer to the working end - the bulk of the metal is too hot for the joint, and the heat flowing down the constriction allows it to cool a little. Possibly more importantly, the thermal constrictions also help balance the heat flow between the ends, so that one end doesn't suck all the heat out of the tip. (the bulk has to be too hot, else when you touched it to the piece to be soldered it would cool down below the right temperature. The element in the iron cannot give out heat at the rate the heat flows out at the tip when soldering, it heats the tip up between making joints. The tip looses heat from convection and more importantly radiation when it is not making a joint, but the equilibrium temperature of a fixed wattage iron when left in air is usually far too hot, which is one reason why you want a Temperature Controlled iron if you can afford one. Incidently, those spiral wire stands you sometimes see are partly designed to stop the iron overheating while switched on but not in immediate use) Cladding. I usually iron-plate my bits so they will last longer, but I make sub-millimetre bits with capillary traps [snipped myself, this is long enough already]. Some people nickel plate, but I don't like to, the finish is harder to wet with solder, and the chemicals nastier. Actual cladding is probably beyond the home workshop, but I've never tried. Anyway, you wouldn't need to bother cladding them - the reason for cladding is that the solder dissolves the bit, but it would take ages to eat away a large lump of copper. The tip will oxidise too, but again that will take a long time to matter, just keep the ends covered in fresh solder. You can redress it with a file without worrying about filing away the iron layer, there isn't one ![]() it ever burns away too much to be used. You'll still have to buy the iron, I haven't bought one in years so I'm very out-of-date here, but the Antex TCS, item XY45Y from Maplins at £40, is a 50 watt Temperature Controlled iron. It has the temperature control in the handle. I haven't used the latest model, but the earlier versions are okay to use, although the temperature control isn't terribly accurate. A "proper" adjustable temperature TC iron, which can be controlled within a few degrees, will have a seperate solder station with a transformer and electronics, and a few extra wires for a thermocouple in the iron. Maplins item BP53H is around £50, and seems a good buy. If you are going into production I'd get a ~100w TC iron and station with fume extraction, £150-ish. "Gun" type irons are not suitable. Fixed wattage irons in the 30-250 watt range are easily available, though not through electronics retailers. I'd suggest 40 watts for joining cells. The Weller SP40 is the best-known, around £20, and the only iron for which hammerhead tips are actually available afaik. Cheaper 40W irons are available for around £10, eg http://www.tooled-up.com/Product.asp?PID=4308 at £7, or http://www.tooled-up.com/Product.asp?PID=28096 at £8. And so on. By the way, you do not want the "hammerhead" tips that stained glass people use, they ends are not symmetrical and they are not designed for simultaneous use of both ends (one way to identify them is that they are usually bent slightly in the middle). Another alternative is a butane gas powered iron, about £15; the cheap versions are usully overpowered and get too hot anyway, adding a large tip will cool them down to a sensible temperature. Plus you can do repairs in the field. The tip will be harder to make though. The cheapest solution? Use a 30 watt mains iron, available from around £2 in a market, with a large mass tip which you make as above, and leave it a while to get hot before and between uses. The tips for these are usually solid copper rods which fit into the barrel, and a hammerhead tip would be easy to make for this type of iron. A bit of practice and some patience is needed, but you _can_ do quick joints on cells this way. A bad "tip" (sorry...), but it might be useful - modern electronic solder is lead-free, and a good thing too, but if you are only using it very occasionally then fluxed 60-40 tin/lead solder will probably be a bit easier to use when soldering cells directly, as it melts at a lower temperature, wets slightly more easily, and stays liquid a little longer. And you will be recycling your battery packs, won't you? YMWV, no matter how good the theory is soldering is an art and needs practice to get right! |
#10
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On Sat, 11 Dec 2004 09:51:25 -0800, "patrick mitchel"
calmly ranted: Bah, freeze the cells then do a quicky with a good soldering iron- usually does the deed without damaging the vent plastic on the top (+) of the cell.- did the same for a bunch of makita 9.6 stick packs/a drill master 12 v battery (2 of them) and a 9.6 black and decker. Can get the cells pretty reasonably at batteryspace.com or american scientific had some 6v-sub c packs for sale pretty cheap- but used. Pat Aren't these stainless cans? I've never had good luck soldering them. I tried a few years ago and they didn't hold together worth a damn. ================================================== ============ Like peace and quiet? Buy a phoneless cord. http://www/diversify.com/stees.html Hilarious T-shirts online ================================================== ============ |
#11
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On Sat, 11 Dec 2004 12:17:09 -0800, Tim Wescott
calmly ranted: Larry Jaques wrote: I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? If the cells are that old they're all at end-of-life anyway. Buy all new cells and build your own pack. Batteries America will cell you sells (?). I can buy new packs off Ebay for less than I can get new cells locally. But I hate to toss good cells if they can be put to use once again. Besides, I'm a tighta^H^H^H^H^H^Hfrugal person. ================================================== ============ Like peace and quiet? Buy a phoneless cord. http://www/diversify.com/stees.html Hilarious T-shirts online ================================================== ============ |
#12
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reposted, original seems lost in the aether, apologies if double posted
Larry Jaques wrote: I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? I've never _re_built packs, but I have soldered them together. The best way I know is to use a hot hammerhead iron - that's a soldering iron with a bit with two working ends, so you heat both cells at once. The bit is about 1 inch long and 1/2 inch diameter, and looks like this: | iron | || | ___||___ | _/ \_ | |_ bit _| | \________/ | I have turned a few from copper, it's not hard - unfortunately I don't have any now, and I can't get back to the shop before mid-Jan (long holidays!). You really need at least a 40 watt iron, although it can be done with a smaller one. Wait for it to get hot People who make up a lot of packs tend to put the cells in the fridge before soldering, use 60/40 tin/lead solder rather than the leadfree type (naughty, but then the cells are full of cadmium ...), and make up a frame so the cells slide easily into the right position. You heat up the ends of two cells at once, make sure they are wet with solder, remove the iron and quickly slide one cell to meet the other. Then cover with heatshrink for mechanical strength. Never had a problem once I figured out how to do it - and you could of course practice with the hootered cells first. It might be worth while googling "hammerhead soldering cell" , some good links there. Below is a post I wrote in answer to a similar question, not an immediate answer but should have some relevant tips. However, Tim's point about reversal during discharge sounds relevant. I've always been a good boy and never tried mixing cells tho'. Perhaps you could try to find the set of cells whose capacities match best. -- Peter Fairbrother Hawkey wrote: Sh*T u aint kidding...30 odd pounds just for the bit!! I think I will forget it. thanks anyway ;-) Presuming you want to use it to end-to-end solder a few battery packs, why not just get a lump of copper, shape it, stick it on the end of an existing bit, preferably a worn-out one, and use that? You could use tap-and-die to thread it, or hard solder/braze, or just drill an undersized hole and hammer it together, whatever seems appropriate and available to attach the lump of copper. Should be almost free. Shape. Shape it like the bits you see in photographs, either with the ends like the end of a flat screwdriver with the tip cut off, or with the ends round with an extra lump in the middle between the ends. The cross section area at the middle should be about 3x the area of the working ends. The bulk of the metal holds the heat, and you want a good but not too good thermal transfer to the working end - the bulk of the metal is too hot for the joint, and the heat flowing down the constriction allows it to cool a little. Possibly more importantly, the thermal constrictions also help balance the heat flow between the ends, so that one end doesn't suck all the heat out of the tip. (the bulk has to be too hot, else when you touched it to the piece to be soldered it would cool down below the right temperature. The element in the iron cannot give out heat at the rate the heat flows out at the tip when soldering, it heats the tip up between making joints. The tip looses heat from convection and more importantly radiation when it is not making a joint, but the equilibrium temperature of a fixed wattage iron when left in air is usually far too hot, which is one reason why you want a Temperature Controlled iron if you can afford one. Incidently, those spiral wire stands you sometimes see are partly designed to stop the iron overheating while switched on but not in immediate use) Cladding. I usually iron-plate my bits so they will last longer, but I make sub-millimetre bits with capillary traps [snipped myself, this is long enough already]. Some people nickel plate, but I don't like to, the finish is harder to wet with solder, and the chemicals nastier. Actual cladding is probably beyond the home workshop, but I've never tried. Anyway, you wouldn't need to bother cladding them - the reason for cladding is that the solder dissolves the bit, but it would take ages to eat away a large lump of copper. The tip will oxidise too, but again that will take a long time to matter, just keep the ends covered in fresh solder. You can redress it with a file without worrying about filing away the iron layer, there isn't one ![]() it ever burns away too much to be used. You'll still have to buy the iron, I haven't bought one in years so I'm very out-of-date here, but the Antex TCS, item XY45Y from Maplins at £40, is a 50 watt Temperature Controlled iron. It has the temperature control in the handle. I haven't used the latest model, but the earlier versions are okay to use, although the temperature control isn't terribly accurate. A "proper" adjustable temperature TC iron, which can be controlled within a few degrees, will have a seperate solder station with a transformer and electronics, and a few extra wires for a thermocouple in the iron. Maplins item BP53H is around £50, and seems a good buy. If you are going into production I'd get a ~100w TC iron and station with fume extraction, £150-ish. "Gun" type irons are not suitable. Fixed wattage irons in the 30-250 watt range are easily available, though not through electronics retailers. I'd suggest 40 watts for joining cells. The Weller SP40 is the best-known, around £20, and the only iron for which hammerhead tips are actually available afaik. Cheaper 40W irons are available for around £10, eg http://www.tooled-up.com/Product.asp?PID=4308 at £7, or http://www.tooled-up.com/Product.asp?PID=28096 at £8. And so on. By the way, you do not want the "hammerhead" tips that stained glass people use, they ends are not symmetrical and they are not designed for simultaneous use of both ends (one way to identify them is that they are usually bent slightly in the middle). Another alternative is a butane gas powered iron, about £15; the cheap versions are usully overpowered and get too hot anyway, adding a large tip will cool them down to a sensible temperature. Plus you can do repairs in the field. The tip will be harder to make though. The cheapest solution? Use a 30 watt mains iron, available from around £2 in a market, with a large mass tip which you make as above, and leave it a while to get hot before and between uses. The tips for these are usually solid copper rods which fit into the barrel, and a hammerhead tip would be easy to make for this type of iron. A bit of practice and some patience is needed, but you _can_ do quick joints on cells this way. A bad "tip" (sorry...), but it might be useful - modern electronic solder is lead-free, and a good thing too, but if you are only using it very occasionally then fluxed 60-40 tin/lead solder will probably be a bit easier to use when soldering cells directly, as it melts at a lower temperature, wets slightly more easily, and stays liquid a little longer. And you will be recycling your battery packs, won't you? YMWV, no matter how good the theory is soldering is an art and needs practice to get right! |
#13
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I've done a bit of rebuilding myself. What I've done is to make sure that I
solder to the tab left over after I've cut it free from the bad cell. This keeps the heat down on the cell itself. I also use a good hot iron and work quickly, first tinning the tab and then letting the battery get back to normal before soldering the two batteries together. -- Why isn't there an Ozone Hole at the NORTH Pole? |
#14
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Larry Jaques wrote:
I can buy new packs off Ebay for less than I can get new cells locally. But I hate to toss good cells if they can be put to use once again. Besides, I'm a tighta^H^H^H^H^H^Hfrugal person. I guess the point is that they're not good cells at this point -- they're just cells that haven't given up quite yet. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
#15
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![]() "Larry Jaques" wrote in message ... I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? TIA. You might be able to find new packs on ebay at a very decent price. |
#16
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On Sun, 12 Dec 2004 00:37:41 +0000, Peter Fairbrother
calmly ranted: reposted, original seems lost in the aether, apologies if double posted It came through, too. Larry Jaques wrote: Who here has rebuilt packs and how did you attach the cells? I've never _re_built packs, but I have soldered them together. OK, I'll see what I have in real solder and give it a try on the old dead cells. I don't need the double head because I'll keep the tab on the good cell to affix to the new pack. You really need at least a 40 watt iron, although it can be done with a smaller one. Wait for it to get hot I have a brand new 100w stained glass iron, temp controller, and flux, but I'll probably use the Weller soldering gun. People who make up a lot of packs tend to put the cells in the fridge before soldering, use 60/40 tin/lead solder rather than the leadfree type (naughty, but then the cells are full of cadmium ...), and make up a frame so the cells slide easily into the right position. You heat up the ends of two cells at once, make sure they are wet with solder, remove the iron and quickly slide one cell to meet the other. Then cover with heatshrink for mechanical strength. It comes with a plastic cover and a fiber/mica shield on top. Both are reusable. Never had a problem once I figured out how to do it - and you could of course practice with the hootered cells first. Hootered cells? I didn't know there were male and female NiCads. g (See www.Hooters.com for our idea of what that word means.) chuckle However, Tim's point about reversal during discharge sounds relevant. I've always been a good boy and never tried mixing cells tho'. Perhaps you could try to find the set of cells whose capacities match best. Both packs were in the same kit originally and may even be from the same batch, so that may not be a problem. Thanks, all. (But where are the fake spotwelder recipes?) -- From time to time, we have been tempted to believe that society has become too complex to be managed by self-rule, that government by an elite group is superior to government for, by, and of the people. But if no one among us is capable of governing himself, then who among us has the capacity to govern someone else? All of us together, in and out of government, must bear the burden. The solutions we seek must be equitable, with no one group singled out to pay a higher price. -President Ronald Reagan First Inaugural Address Tuesday, January 20, 1981 |
#17
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On Sat, 11 Dec 2004 16:50:47 -0800, Tim Wescott
calmly ranted: Larry Jaques wrote: I can buy new packs off Ebay for less than I can get new cells locally. But I hate to toss good cells if they can be put to use once again. Besides, I'm a tighta^H^H^H^H^H^Hfrugal person. I guess the point is that they're not good cells at this point -- they're just cells that haven't given up quite yet. They're only about 2.5 years old and have had maybe 50 charges each, so my guess is that they still have life in them. Of course, I'll reglue a sneaker whose sole tried to fall off if the uppers are in good condition, too. YMMV. -- From time to time, we have been tempted to believe that society has become too complex to be managed by self-rule, that government by an elite group is superior to government for, by, and of the people. But if no one among us is capable of governing himself, then who among us has the capacity to govern someone else? All of us together, in and out of government, must bear the burden. The solutions we seek must be equitable, with no one group singled out to pay a higher price. -President Ronald Reagan First Inaugural Address Tuesday, January 20, 1981 |
#18
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On Sat, 11 Dec 2004 20:29:10 -0500, "ATP"
vaguely proposed a theory .......and in reply I say!: remove ns from my header address to reply via email (1) You might look at NiMH cells as replacements. I know this is not in answer to your question, but you get a HEAP more energy per charge.....= longer running. You might be able to find new packs on ebay at a very decent price. But buy only a few until you have tested them, and NEVER buy Titanium brand. I bought 16 from bloody Ebay, and well over half got very hot and leaked when charged -by the charger supplied by the battery vendor-, and also on my other smart charger that had successfully charged many a NiMH until then. I returned them (postage starting to eat into "savings") and they came back "tested"...with the crystalline crap still showing on them! Never again. Maybe my loss, but I have had one good, and two bad, encounters with dealers on Ebay. Enough. I never even had a reply on the lack of the 4 x AA NiMH cells I was supposed to get with the charger. I found a few other complaints about these Titanium brand. They claim a .1% failure rate or something. Well in that case, suck it up guys, and keep sending me new ones until I get decent bloody cells! Oh yeah, and the rating system. This mob that sold to me had a 98.7% favourable rating. So maybe I am just the unluckiest SOB on the Net. --- Only worry about the things you can control. Then you have stuff all to worry about! |
#19
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On Sun, 12 Dec 2004 12:08:40 +0800, the renowned Old Nick
wrote: I found a few other complaints about these Titanium brand. They claim a .1% failure rate or something. Well in that case, suck it up guys, and keep sending me new ones until I get decent bloody cells! There's circumstantial evidence that counterfeit Sony NiMH cells are being sold on eBay. They have markedly lower capacity than the real Sony cells. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
#20
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Bob May wrote:
I've done a bit of rebuilding myself. What I've done is to make sure that I solder to the tab left over after I've cut it free from the bad cell. This keeps the heat down on the cell itself. I also use a good hot iron and work quickly, first tinning the tab and then letting the battery get back to normal before soldering the two batteries together. -- Why isn't there an Ozone Hole at the NORTH Pole? Yep - what everyone is talking about a hot iron is not temperature, but the temp after putting it on a sink. This really indicates a large or massive (physically) heater and tip. It might be a 100 or 150 watt iron. Notice this isn't the temp like 700 degree. One would expect these to reach that temp easily after warm up time. File the tip clean - and use the heal of your shoe (inside parts to keep them looking nice) as a shield. This melted rubber (stinks a little) coats the iron so solder won't run all over the tip or the back... Have a area the size needed tinned once the rest is shielded. Martin [ who owns a 100 Watt Black Beauty and gave his 300 watt to a friend doing gutters ] -- Martin Eastburn, Barbara Eastburn @ home at Lion's Lair with our computer NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder |
#21
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and again, maybe third time lucky!
reposted, original seems lost in the aether, apologies if double posted Larry Jaques wrote: I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? I've never _re_built packs, but I have soldered them together. The best way I know is to use a hot hammerhead iron - that's a soldering iron with a bit with two working ends, so you heat both cells at once. The bit is about 1 inch long and 1/2 inch diameter, and looks like this: | iron | || | ___||___ | _/ \_ | |_ bit _| | \________/ | I have turned a few from copper, it's not hard - unfortunately I don't have any now, and I can't get back to the shop before mid-Jan (long holidays!). You really need at least a 40 watt iron, although it can be done with a smaller one. Wait for it to get hot People who make up a lot of packs tend to put the cells in the fridge before soldering, use 60/40 tin/lead solder rather than the leadfree type (naughty, but then the cells are full of cadmium ...), and make up a frame so the cells slide easily into the right position. You heat up the ends of two cells at once, make sure they are wet with solder, remove the iron and quickly slide one cell to meet the other. Then cover with heatshrink for mechanical strength. Never had a problem once I figured out how to do it - and you could of course practice with the hootered cells first. It might be worth while googling "hammerhead soldering cell" , some good links there. Below is a post I wrote in answer to a similar question, not an immediate answer but should have some relevant tips. However, Tim's point about reversal during discharge sounds relevant. I've always been a good boy and never tried mixing cells tho'. Perhaps you could try to find the set of cells whose capacities match best. -- Peter Fairbrother Hawkey wrote: Sh*T u aint kidding...30 odd pounds just for the bit!! I think I will forget it. thanks anyway ;-) Presuming you want to use it to end-to-end solder a few battery packs, why not just get a lump of copper, shape it, stick it on the end of an existing bit, preferably a worn-out one, and use that? You could use tap-and-die to thread it, or hard solder/braze, or just drill an undersized hole and hammer it together, whatever seems appropriate and available to attach the lump of copper. Should be almost free. Shape. Shape it like the bits you see in photographs, either with the ends like the end of a flat screwdriver with the tip cut off, or with the ends round with an extra lump in the middle between the ends. The cross section area at the middle should be about 3x the area of the working ends. The bulk of the metal holds the heat, and you want a good but not too good thermal transfer to the working end - the bulk of the metal is too hot for the joint, and the heat flowing down the constriction allows it to cool a little. Possibly more importantly, the thermal constrictions also help balance the heat flow between the ends, so that one end doesn't suck all the heat out of the tip. (the bulk has to be too hot, else when you touched it to the piece to be soldered it would cool down below the right temperature. The element in the iron cannot give out heat at the rate the heat flows out at the tip when soldering, it heats the tip up between making joints. The tip looses heat from convection and more importantly radiation when it is not making a joint, but the equilibrium temperature of a fixed wattage iron when left in air is usually far too hot, which is one reason why you want a Temperature Controlled iron if you can afford one. Incidently, those spiral wire stands you sometimes see are partly designed to stop the iron overheating while switched on but not in immediate use) Cladding. I usually iron-plate my bits so they will last longer, but I make sub-millimetre bits with capillary traps [snipped myself, this is long enough already]. Some people nickel plate, but I don't like to, the finish is harder to wet with solder, and the chemicals nastier. Actual cladding is probably beyond the home workshop, but I've never tried. Anyway, you wouldn't need to bother cladding them - the reason for cladding is that the solder dissolves the bit, but it would take ages to eat away a large lump of copper. The tip will oxidise too, but again that will take a long time to matter, just keep the ends covered in fresh solder. You can redress it with a file without worrying about filing away the iron layer, there isn't one ![]() it ever burns away too much to be used. You'll still have to buy the iron, I haven't bought one in years so I'm very out-of-date here, but the Antex TCS, item XY45Y from Maplins at £40, is a 50 watt Temperature Controlled iron. It has the temperature control in the handle. I haven't used the latest model, but the earlier versions are okay to use, although the temperature control isn't terribly accurate. A "proper" adjustable temperature TC iron, which can be controlled within a few degrees, will have a seperate solder station with a transformer and electronics, and a few extra wires for a thermocouple in the iron. Maplins item BP53H is around £50, and seems a good buy. If you are going into production I'd get a ~100w TC iron and station with fume extraction, £150-ish. "Gun" type irons are not suitable. Fixed wattage irons in the 30-250 watt range are easily available, though not through electronics retailers. I'd suggest 40 watts for joining cells. The Weller SP40 is the best-known, around £20, and the only iron for which hammerhead tips are actually available afaik. Cheaper 40W irons are available for around £10, eg http://www.tooled-up.com/Product.asp?PID=4308 at £7, or http://www.tooled-up.com/Product.asp?PID=28096 at £8. And so on. By the way, you do not want the "hammerhead" tips that stained glass people use, they ends are not symmetrical and they are not designed for simultaneous use of both ends (one way to identify them is that they are usually bent slightly in the middle). Another alternative is a butane gas powered iron, about £15; the cheap versions are usully overpowered and get too hot anyway, adding a large tip will cool them down to a sensible temperature. Plus you can do repairs in the field. The tip will be harder to make though. The cheapest solution? Use a 30 watt mains iron, available from around £2 in a market, with a large mass tip which you make as above, and leave it a while to get hot before and between uses. The tips for these are usually solid copper rods which fit into the barrel, and a hammerhead tip would be easy to make for this type of iron. A bit of practice and some patience is needed, but you _can_ do quick joints on cells this way. A bad "tip" (sorry...), but it might be useful - modern electronic solder is lead-free, and a good thing too, but if you are only using it very occasionally then fluxed 60-40 tin/lead solder will probably be a bit easier to use when soldering cells directly, as it melts at a lower temperature, wets slightly more easily, and stays liquid a little longer. And you will be recycling your battery packs, won't you? YMWV, no matter how good the theory is soldering is an art and needs practice to get right! |
#22
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Larry
Try a little Stay-Clean (a Harris proiduct) as the flux next time you want to soft solder stainless. It makes soft soldering stainless easy. I have been successfull with soldering tabs on all the "good quality" batteries I've worked with. I have ruined some "import/low cost" cells by overheating them with the soldering iron. Jerry "Larry Jaques" wrote in message ... On Sat, 11 Dec 2004 09:51:25 -0800, "patrick mitchel" calmly ranted: Bah, freeze the cells then do a quicky with a good soldering iron- usually does the deed without damaging the vent plastic on the top (+) of the cell.- did the same for a bunch of makita 9.6 stick packs/a drill master 12 v battery (2 of them) and a 9.6 black and decker. Can get the cells pretty reasonably at batteryspace.com or american scientific had some 6v-sub c packs for sale pretty cheap- but used. Pat Aren't these stainless cans? I've never had good luck soldering them. I tried a few years ago and they didn't hold together worth a damn. ================================================== ============ Like peace and quiet? Buy a phoneless cord. http://www/diversify.com/stees.html Hilarious T-shirts online ================================================== ============ |
#23
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On Sun, 12 Dec 2004 06:49:31 +0000, Peter Fairbrother
vaguely proposed a theory .......and in reply I say!: remove ns from my header address to reply via email and again, maybe third time lucky! reposted, original seems lost in the aether, apologies if double posted We have seen all 3 posts, or I have. --- Only worry about the things you can control. Then you have stuff all to worry about! |
#24
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![]() Larry Jaques wrote in message Aren't these stainless cans? I've never had good luck soldering them. I tried a few years ago and they didn't hold together worth a damn. If they are stainless, I havent had a problem getting the solder to stick.I was using a weller soldering gun (140 watts I think) with some thick copper wire as the tip. Some of the cells have exhibited rust when left to the elements.I usualy hit the area to be soldered with a coarse sandpaper, and use a "nokorode" soldering flux- cleaning the flux off afterwards. I try to peel the solder tabs off the dead cells with some needle nose pliers. Usually successful. I tried to solder the cells directly without the solder tabs but found that if you drop the pack : ( then the solder joint breaks- I guess since there isn't any flex in the solder.The whole idea of tossing something in the waste stream just because it isn't a hunnert % any longer, old or cheap just doesn't cut it with me. There's always more things to spend money on than there is money...(plastic non withstanding) Pat |
#25
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On Sat, 11 Dec 2004 08:24:54 -0800, Larry Jaques
wrote: I recently replaced one of the two dead Ryobi 14.4v batt packs which several years of abuse before dying on me. It appears that just a few of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. Who here has rebuilt packs and how did you attach the cells? TIA. Soldering works fine if you use a hot iron (at least 20w) and complete the joint in no more than two or three seconds. Use 60-40 lead/tin solder and an active flux - Bakers soldering fluid or similar killed acid type flux so that you get immediate solder wetting. Use the solder connection for electrical continuity only.For mechanical retention use epoxy resin assisted as appropriate by duct tape or shrink wrap. Jim |
#26
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On Sun, 12 Dec 2004 06:49:31 +0000, Peter Fairbrother
calmly ranted: and again, maybe third time lucky! reposted, original seems lost in the aether, apologies if double posted Triple-posted. -- From time to time, we have been tempted to believe that society has become too complex to be managed by self-rule, that government by an elite group is superior to government for, by, and of the people. But if no one among us is capable of governing himself, then who among us has the capacity to govern someone else? All of us together, in and out of government, must bear the burden. The solutions we seek must be equitable, with no one group singled out to pay a higher price. -President Ronald Reagan First Inaugural Address Tuesday, January 20, 1981 |
#27
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Larry Jaques wrote:
of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. I see anumber of suggestions about soldering cells together directly. IMO, this is a very bad idea. I've never ssen a comercial pack done this way. If successful at all, any vibration or mechanical stress would almost certainly either cause the connection to fail or damage the top of the cell. If you are going to try soldering, use bit of copper braid, preferably pre-tinned such as a bit of the shield braid off a piece of coax. Cut off a length about equal to a cell diameter, tin the very ends and bend in the middle to form a broad V. Tin the cell ends in a small area. Work quickly with a hot iron. solder one end of the braid to the positive end of one cell. Slip a plastic insulating disc over the braid to prevent shorts. Solder the other end of the braid to the other cell's negative then fold to make a compact joint. And, yes, I do plan to build me a capacitor discharge spot welder but I won't give out the circuit 'til I've designed, built and tried it. Ted |
#28
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On Mon, 13 Dec 2004 00:08:07 GMT, Ted Edwards
calmly ranted: Larry Jaques wrote: of the dozen cells in each pack have gone bye-bye. I'd like to rebuild one from the dregs of the other and wondered what you guys used to spotweld the cells together. I've heard that they don't like to be soldered _at_all_. I see anumber of suggestions about soldering cells together directly. IMO, this is a very bad idea. I've never ssen a comercial pack done this way. If successful at all, any vibration or mechanical stress would almost certainly either cause the connection to fail or damage the top of the cell. Good point there, Ted. If you are going to try soldering, use bit of copper braid, preferably pre-tinned such as a bit of the shield braid off a piece of coax. Cut off a length about equal to a cell diameter, tin the very ends and bend in the middle to form a broad V. Tin the cell ends in a small area. Work quickly with a hot iron. solder one end of the braid to the positive end of one cell. Slip a plastic insulating disc over the braid to prevent shorts. Solder the other end of the braid to the other cell's negative then fold to make a compact joint. Used desoldering wick works well for that. BTDT, fixed the Bose 501 woofer carbon leads that way twice in the last decade and a half. And, yes, I do plan to build me a capacitor discharge spot welder but I won't give out the circuit 'til I've designed, built and tried it. OK, I'll give you until (how does next Wednesday sound?) to do that. ![]() -- REBOOT AMERICA! ----------------------- http://diversify.com Website Programming |
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