Connecting different gauge wires

Soldering is prefered by many

My goal with a wire connection is one that it is not only connected 100% of the time but one that is strong and protected from the elements.  The issue of having a strong connection comes with the fact that the battery may pull on the connection in cases of crashes. A very fast, and simple connection would be to simply use wire nuts.  If I were to use batteries with different connectors, one with an XT60 connector and another with a JT connector I would be tempted to use wire nuts because I could change out the connectors before the speed controller.   But, that's a bit more work than it's worth.  I would also worry about the connection over time as the wires would be bent onto each other over and over again.    I also do want some protection from the elements and most importantly to ensure that there is no way the positive and negative wires would ever touch.



Talk to any old-time electrician and they will swear about soldering.  Soldering a 10 gauge wire to a 16 gauge wire is something that they have no issue with.  I do because that 10 gauge wire takes a lot of heat to heat up and at the ranges hot enough to melt solder it also melts the insulation around the wires.  A good crimp is a close second.  If you gauge effort, time and the final results there are many who swear by crimping.  

100% of the time connection

My Radian had a slight electrical connection issue.  There was a connection between the battery and speed controller that would fail if the wire was twisted in a certain way.  It was super easy to fix and worked most of the time.   Perhaps this little issue wasn't worth worrying about?  Of course, you never can really tell when a connection would fail. Maybe it would be just momentary and the servos would bounce back on once power was restored?  The motor wouldn't be ready for at least 10 seconds as the speed controller goes through its fire-up song.    The good news is that no matter what the plane would soon be back on the ground, most likely in a debris field.  I know that "Build, fly, crash, repeat" is our motto.  Yet, a little extra caution will decrease the down time.

The problem-Different wire gauges



My preferred crimping method

The cheap plastic crimps mainly from China are fine for some applications. If I were wiring two pieces of speaker wire together inside a house it would be fine. I would simply make certain to keep the insulation inside the crimp to prevent shorting.   When you put a heat shrink around it the heat causes the plastic to bend back to its normal round shape.  And then there's the issue of wire gauges which are different gauges.  The connection of the thinnest gauge will always be suspect.
For connections, if different gauges, ones that will be exposed to the elements I use non-insulated step-down crimps.
  The step-down crimps can be found in many different flavors, insulated, non-insulated, and ones that are heat shrink crimps.  Sure they are more expensive than the bag of 100 crimps for $5 but they work all of the time.  Putting heat shrink around them doesn't affect the crimp.   For what I have found it's the best solution for getting it right the first time.