Battery pigtail too short: solder vs crimp

[drbenjamin]

Hi All
I’m setting up a recumbent mid drive ebike and the battery pigtails do not reach the connectors on the motor. I was thinking of making an extension with 12ga wires and crimping it at both ends. Is this reasonable or should I be soldering new longer wires to the battery terminals? Not sure my soldering iron is up to that challenge but I’ll figure it out if it’s safer/better
Thanks!

 

[Gruesome]

It might be easier to buy a preconfigured extension cable with the right connectors at both ends.

 

[Diggs]

Personally, I'm never a fan of crimping unless it's a hydraulic crimper on very large gauge wire. (Auto battery size "0" or "00" wire) I solder everything up to and including 8 ga. wire.

 

[docw009]

For 12G wires, I use the metal forms inside the crimp terminals, discarding the plastic exterior. Put them together and it is easy to solder them. Then I cover the junction with heat shrink. Of course, they make meltable crimps with solder inside that do the same thing, but I'm dubious of how it works in real life. It might be invaluable for a highway fix, if a lighter can stay lit and put out enough heat, If it's temporary, wire nuts are a lot cheaper and don't need heat.

As I found myself often soldering wires to connectors and splicing them, the little stands that have two adjustable alligator clips to hold the wires became invaluable,

 

[drbenjamin]

Thanks guys - I’ve been crimping power connections because I’d read that solder can become brittle. I could easily solder in an extension if that’s legit for a power cable. 52v and 20A max on my bike.
thanks Gruesome but the motor already has bare ends so no preconfigured cable

 

[99t4]

What becomes brittle is the area where the solder wicks up thru the wire strands. That intersection there at the far edge where the solder ends becomes a stress riser for wire strand breakage if there is subsequent movement or vibration in that area.

There are ways to mitigate this-- use graduated diameters of heatshrink tubing to form a "cast" around the soldered area; secure the wiring well to minimize movement, etc.

Crimping works well also. In fact, most industrial applications (automobiles, airplanes, etc.) have long favored crimp vs. solder connections.

MOSTLY it depends on user skill and quality of materials. You might want to practice before working on the real work piece.