John Bunting Posted November 2, 2007 Share Posted November 2, 2007 I need to replace some small NiMH cells in a cheap RTF model. They are the same diameter as an AAA cell, but about one-third of the length, and I think 120 or 150 mAH capacity. So far, I can't find anyone who sells them. Does anyone know of a possible supplier? Thanks. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 2, 2007 Share Posted November 2, 2007 http://www.overlander.co.uk/products/default.asp?cid=2&scid=41&pid=1276Is this it ? Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted November 2, 2007 Share Posted November 2, 2007 I have loads of small NiMh 3.6V a little greater dia. than AAA and about a 1/4 of thier length if anyone is interested. LED lights maybe? Probably the wrong voltage for your RTF though. Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 4, 2007 Share Posted November 4, 2007 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
none.none Posted November 5, 2007 Share Posted November 5, 2007 try:http://www.component-shop.co.uk/html/single_cells.html ive found them very reliable they can make up packs for you too, or you can buy packs from their ready made list. Quote Link to comment Share on other sites More sharing options...
John Bunting Posted November 5, 2007 Author Share Posted November 5, 2007 Thanks, Timbo, Martin, Eric and Adam, for your help. Component-shop sem to have just what I want, 1/4 and 1/3 AAA cells at very reasonable prices. Can't see anything similar on Maplin or Overlander, and cordless phone packs all seem to be larger cells, but your 3.6v packs, Martin, sound about the right cell size. If you feel like selling me a few I can probably split one or two up and add cells to others to make 4.8 or 6v packs. Thanks, everyone.As a point of interest, for anyone who makes up their own packs, I see that John Emms on the Puffin website recommends soldered rather than spot-welded cell links, for minimum resistance. This is OK as long as you do the soldering quickly, to avoid overheating the cells, so I think you need the cell ends and the connecting strip pre-tinned, and an iron with good thermal capacity, so it doesn't cool off as soon as it contacts the cell.I was looking around for something to use for connecting strips, and hit on some copper plant labels, which should be available at any garden centre. Mine are .006 inch copper sheet, quite flexible and easily cut with scissors. Checking the resistance, I found that a strip about 1/8 inch wide and 1 inch long has a resistance of about 1 milli-ohm, which should be OK for low to medium currents, say up to 20 Amps. Above that, something a bit thicker might be advisable. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 6, 2007 Share Posted November 6, 2007 I used ( when I was still using such antique power supply ) either proper joining strips ( again from puffin ) or outer sheath copper braiding from large Co-Ax cable. I have a couple of hammerhead soldering iron bits here which are surplus if anyone wants one. A large iron ( 100watts I used ) is ESSENTIAL Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted November 6, 2007 Share Posted November 6, 2007 John, please email me for further details. I believe that there is an email button somewhere that you can use. The packs are approx. 12mm dia. and 10mm long, weighing 4g each and can easily be split with a knife. I would only want a nominal sum for say 10 packs. I use desoldering braid to join cells. Just looked at a pack which is typical of a central heating back-up battery, and realised that even this, though much larger, is only 150mAh capacity so you may have to take chance and use the small packs in parallel. Would be great for LED lightng. Quote Link to comment Share on other sites More sharing options...
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