I've got a postage scale, on which that the 9V battery connector has fallen off, I bought a new one online for £1 (as below), the new one already has cables coming out of it and the postage scale has cables coming out of it, the cables are quite fine as you can imagine (about 1mm diameter), what's the best way to connect the cables from the postage scale to the cables on the 9V connector?
I thought of ripping the cables out of the connector and soldering the scales cables onto the connector, but I thought there could be an easier way.
The other thing I thought of was to use a box connector as the image below, but I think the wires may be too fine.
Best Answer
The best way is to desolder the old cables from the scale's circuit board, and solder on the new ones. That way there are no messy splices. However, to do that easily you may need a solder pump (cost: about $5-$10 USD) to vacuum away the solder from the existing joints. Without a solder pump, you can desolder a through-hole-mounted wire simply by pulling it away while the solder is liquid, but solder may clog the hole. To get around this, you can heat the solder that remains in the hole while inserting the new wire; if you can't get at it with the tip of the iron, then simply add more solder to the area.
The next choice after that is to make rat tail joints (stripped ends of wires twisted together) between the new and existing cable (or else Western Union splice which is neater), and then strengthen these joints with solder and perhaps cover with electrical tape or hot glue. The Western Union is not well-suited for braided wire, but this is only true of the splice alone, not if the splice is flooded with solder.