Waterproof wire nuts vs soldering connections

81style

10 mW
Joined
Jan 12, 2018
Messages
33
Location
Southern California, USA
Looking for a sanity check here....

For electrical connections tucked away inside my EEB frame, would waterproof wire nuts suffice (as opposed to solder + heat shrink)? Using wire nuts may be a easy way to expedite my build without sacrificing functionality, durability, and safety. However, I do realize I may encounter space limitations inside the frame.

Thoughts?
 
For any connection that is critical and could result in damage if it was corroded or loosened in any way, i'd say no.

..which would include most of the connections needed for an ebike.

Do it right and solder it.
On the phase wires, double up the heat shrink as well.
 
Hell, i just had to deal with a customer who used those wire nut things for his battery connection on a build that only drew 25A.

When i moved the battery, the negative wire slipped right off and touched the frame. Good thing it wasn't the positive, cuz i could potentially have had 52 volts going through my body at that moment.

Even the worst China seller selling factory seconds and fake merchandise doesn't ship things connected this way.
 
Wire nuts work fine on 120V house connections. The higher volts can easily penetrate mild oxidation (copper is brown instead of bright reddish).

Plus...houses don't experience the same moisture, vibration, and jolts that an ebike experiences...

Even if a wire nut holds the connection for a year, it will go bad, and you will have to fix it. So...you can spend time on it now (in a garage with a radio and a beer), or spend time on it later, halfway through a ride.
 
Wire nuts are a no no. If you're worried about soldering adding a lot of time, go to the hardware store and get some butt crimps. Then you can securely and permanently join wires in a way that's just as easy as wire nuts.
 
I've had a couple wires slip out of those things over the years, usually when the motor or controller came from you know where..

I just like soldering with good ol' fashioned lead. It's never done me wrong, through 17 ebikes, 12 car stereo installs, and a gazillion repairs and electronics customizations over the years.
 
I used waterproof wire nuts that came prefilled with dielectric grease for the mains wires to my 240VAC welder, when I first built the extension cord for it (to reach the only outlet I could use for it, fairly far inside the house from the backyard where I use the welder).

They worked ok, though when I first made it I pulled a wire out when pulling the cable from the welder to the outlet.

The system worked better once I soldered the cable together, and added a regular (screwterminal) plug/socket between the extension and the welder. I'd've preferred crimping with lugs but I don't have a crimper good enough for that.
 
Try These https://smile.amazon.com/dp/B07HJ2L7BD/?coliid=I2F8SONXZFGIOB&colid=11H11PDJTU4GU&psc=0&ref_=lv_ov_lig_dp_it
 
I wouldn't relay on wire nuts alone. Wire nuts, properly twisted, also rapped in some sort of self sealing silicone tape should be ok.
Get the right size for your wires. Keep the wires being twisted together as similar gauge as possible.
Just remember, the wire nuts on their own can wiggle free. And, a well tugged wire can be pulled out. If you are going to relay on anything on your e-bike, relay on good maintenance.

:D :bolt:
 
The problem with soldering is that it can promote work hardening of the copper wire and you can break soldered connections with repeated vibration. That is why some people prefer crimping. The problem with crimping is that you need to make sure you know how to make a good crimped connection and you need to have the right crimping sleeves.

That said, I mostly solder connections and then enclose them with relatively long shrink wrap. My thinking is that longer shrink wrap can act as a strain relief. I do this because I don't want to stock a whole bunch of different crimp sleeves for the small amount of wiring that I do. But I should probably switch to crimping.

https://millennialdiyer.com/articles/motorcycles/electrical-repair-crimp-or-solder/
 
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