I have a wire that fits atop my 9 V battery and it should easily feed into a breadboard but it does not as the wire is stranded.

I tried last week to solder these wire strands to breadboard jumper wires so I could feed them into my bread board, but they just don't allow current to flow through; this did not work despite my efforts and even using heat shrink.

Is there a component that would do this better or some soldering technique I should be using instead?

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    \$\begingroup\$ Show a photo of your crime. \$\endgroup\$
    – Transistor
    Sep 16, 2022 at 21:03
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    \$\begingroup\$ @leeand00 You can buy them already done up like that. Or, you can peal back the top side thin plastic on your 9V connector and cut the stranded wire away from there and replace it with solid wires and then superglue the plastic toupee back together, again. Screwing around with a solid wire and stranded wire joint in the middle just leaves you with a weak joint that will cause no end of trouble. \$\endgroup\$
    – jonk
    Sep 16, 2022 at 21:10
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    \$\begingroup\$ You can also solder the stranded wires to a couple pins of a 2.54mm/0.1" pitch header and plug that into the breadboard. Use some heat shrink to increase the bend radius at the solder's edge if you want it to last. \$\endgroup\$ Sep 16, 2022 at 21:13
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    \$\begingroup\$ Heatshrink is an insulator. That will have no effect on conductivity other than preventing short circuits. It's your soldered joint that is the problem or the type of wire you have selected. What are the "hard wires" made of? They should be copper. If you can't solder to them with resin-cored solder and a decent, hot enough soldering iron then you've got something else. \$\endgroup\$
    – Transistor
    Sep 16, 2022 at 21:18
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    \$\begingroup\$ You could get any used battery disassemble it and use the Top part. Then weld wires to any + 16V electrolytic capacitor (radial is better), wind and solder the flexible wire on the capacitor terminals. This provides two features: (1) gives you 2 “rigid” wires for polarized connection on the breadboard, and (2) provides you a filtering capacitance to lower internal resistance and make 9V more stable, being useful in +90% of the circuits you may assemble. Cost: negligible, Fun: see how a 9V battery is made inside. \$\endgroup\$
    – EJE
    Sep 16, 2022 at 21:29

1 Answer 1


This is how I connect small stranded wire to solid wire so I can plug it in to a breadboard.


Note that the stranded wire, in your case the wire from the battery, is wrapped around the sold wire about 5 mm from the end of the solid wire. With heat shrink around the assembly, this will support the stranded wire against the solid wire so the stranded wire won't break when flexed.

Be sure that the soldering flux is removed from the exposed solid wire as the flux will cause poor electrical contact in the breadboard. Isopropyl alcohol will remove the flux.

If you are using cheap breadboards, you will have problems with high resistance connections due to the poor quality of the contacts in the breadboard.


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