My battery tender cable got cut in half on accident. Is a solder connection safe enough to salvage the battery maintainer?
And if you want a really hermetically sealed joint, solder the staggered joints, paint with liquid tape, then heat shrink for tensile strength. Then you can cover the joint with black vinyl electrical tape to minimize the visual effect.The easiest way to do this is cut the two wires in a staggered fashion. IE so each wire is separated by an inch or two from the other opposite polarity wire. Make sure the spacing is sufficient so that the bare wires don't touch.
Slip a piece of appropriately sized heat shrink tube over the wire now. You can get this at Radio Shack. Make sure it's just a little bigger than the wires. Most only shrink by a factor of 2. Also ensure it's long enough to cover both joints.
Twist the wires around each other as opposed to making a pigtail sticking out. Make sure you preserved the polarity otherwise you'll have a battery discharger. Solder both.
Slip the heat shrink tube up over both soldered joints and shrink it. A heat gun is best but the Rat Shack variety will usually shrink with a hair dryer. Done and it usually looks ok too without big lumps etc.