Battery cable connections may be
crimped or soldered; both methods can produce a reliable connections.
Crimping requires a crimper capable of squeezing the connection until the copper
of the cable and of the terminal/lug literally flow into each other. The crimp
should be pull tested to 40 lbs or more to verify that it is solid. Also, flex
the cable at the connection while looking closely at the strands of the wire where they
enter the terminal /lug. Any motion of any strands relative to the connector is too loose,
requiring additional crimp pressure to be applied to the crimp.
The key to a good soldered connection is using the right amount of solder and
heat, as well as the right type and amount of flux. Heat the cable and connector,
using just enough flux to clean both where they will be joined. Make
sure the flux is a non-corrosive rosin type, because there will be flux residue
left in the cable. A corrosive flux, such as that used for plumbing, will
quickly corrode the copper wires.
Then apply solder and heat to the very end of cable until it is thoroughly tinned,
and the solder has wicked into the interior of the cable, but avoid letting
it wick up the cable more than about 1/2".
The soldered section of the cable will be like a solid rod when cooled.
Clamp the connector with the cable opening pointed up,
and insert the cable into the opening in the connector making sure that it
is fully inserted. This may require heating the end of the cable to soften
the solder. Then apply heat to the connector to melt the solder, adding solder as required
to fill the opening. It is important to hold the cable stationary in the connector
until the solder has completely cooled and solidified; any motion will cause
the solder to crystallize, which gives a poor solder joint.
Oh, by the way: if you are using shrink tubing over the cable & connection, put
the shrink is over the cable before you start soldering, and be
sure that the shrink is far enough from the joint that the soldering heat
doesn't cause it to shrink.