Melted an onyx solder joint

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DoNoHarm

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Arrma RC's
  1. Senton 6s
I like running my onyx 3s pack when I hand over the controller to someone inexperienced (its a 6400mah 25c) but today I had it melt the back part of the connector lol.
30372

The wire came unsoldered so I just put on some heatshrink after repairing it. Anyone ever have this happen?
 
I believe we are looking at an XT90 connector. From the picture, it looks like this XT90 was built OEM with the plastic sleeve used on some later gen. XT's. No heat shrink is needed as a result after soldering. The sleeve is just slid up and snaps in place isolating Pos. and Neg. I will surmise that if the neg. soldering joint was in question, i.e. a bad "cold" soldered joint, that it was just plain defective from the get go when the Bat. was assembled. This bad joint ultimately failed from normal use on your rig. It loosened , then arced under load and melted. Ive seen this before.
I use Original Deans plugs for most of my rigs, but the XT connectors are good as well and I use them also. When I solder Xt's I never use the plastic sleeve cap if it is supplied. I toss it. I only use heat shrink. The plastic cap, when slid on after soldering can loosen a bad "cold" solder joint from the pressure of sliding it on. This can mechanically separate or loosen a bad joint or even weaken an other wise good solder joint over time and use.
The sleeve appears to speed up assembly for "mass production" and may look neater but I never liked them. They also tend to come apart and a drop of CA is all you can do to fix it aside from complete removal and replacement. I would clearly replace this XT-90 and after soldering properly, only use generously long heat shrink tubing(25mm) of the "adhesive lined" type. They stay put and are water proof sealed for outdoor use. But any heat shrink tubing is fine.
From experience, I never use the slide on cap. Only heat shrink tubing. This also allows you to see a failing joint before a meltdown. The plastic sleeve conceals an impending failure. I had one similar scenario as yours issue but I caught it in time. Just toss the sleeve.

The above assumes there were no other electrical anomalies with you ESC/ Batt. as a contributing factor. The specs on your Onyx appear adequate for your rig. I'm not partial to Onyx Lipos in general. But that doesn't mean its a bad Bat., aside from the alleged defectively assembled XT90.
You are lucky that your electrics are fine and the batt. didn't blow up.
And hopefully you are not a tad bit "over geared".
Enjoy.
 
I believe we are looking at an XT90 connector. From the picture, it looks like this XT90 was built OEM with the plastic sleeve used on some later gen. XT's. No heat shrink is needed as a result after soldering. The sleeve is just slid up and snaps in place isolating Pos. and Neg. I will surmise that if the neg. soldering joint was in question, i.e. a bad "cold" soldered joint, that it was just plain defective from the get go when the Bat. was assembled. This bad joint ultimately failed from normal use on your rig. It loosened , then arced under load and melted. Ive seen this before.
I use Original Deans plugs for most of my rigs, but the XT connectors are good as well and I use them also. When I solder Xt's I never use the plastic sleeve cap if it is supplied. I toss it. I only use heat shrink. The plastic cap, when slid on after soldering can loosen a bad "cold" solder joint from the pressure of sliding it on. This can mechanically separate or loosen a bad joint or even weaken an other wise good solder joint over time and use.
The sleeve appears to speed up assembly for "mass production" and may look neater but I never liked them. They also tend to come apart and a drop of CA is all you can do to fix it aside from complete removal and replacement. I would clearly replace this XT-90 and after soldering properly, only use generously long heat shrink tubing(25mm) of the "adhesive lined" type. They stay put and are water proof sealed for outdoor use. But any heat shrink tubing is fine.
From experience, I never use the slide on cap. Only heat shrink tubing. This also allows you to see a failing joint before a meltdown. The plastic sleeve conceals an impending failure. I had one similar scenario as yours issue but I caught it in time. Just toss the sleeve.

The above assumes there were no other electrical anomalies with you ESC/ Batt. as a contributing factor. The specs on your Onyx appear adequate for your rig. I'm not partial to Onyx Lipos in general. But that doesn't mean its a bad Bat., aside from the alleged defectively assembled XT90.
You are lucky that your electrics are fine and the batt. didn't blow up.
And hopefully you are not a tad bit "over geared".
Enjoy.
Yeah, actually the battery is pretty under spec’d. It’s a senton 6s and I’m only using a 25c. Battery wasn’t the problem as you said, it was probably a soldering fault. I just finished a run with that repair I showed you and so far it’s been fine, I guess I’ll leave it how it is.
 
There is nothing wrong with your repair. Done well.
Soldering joints should look 'shiny' not dull. Always wipe down the joint with a dab of solvent or similar to remove any excess flux before covering with heat shrink. Any excess flux can deteriorate the joint and/or eat through the heath shrink over time.. A dull looking solder joint is a "cold" joint and they separate/snap apart with undo force when you least expect it. Your solder should flow quick or you tend to get a "cold" dull looking joint.
Using heat shrink instead of the plastic sleeve cover makes it more visible for a quick inspection between runs. I've done the same repair so I could run until I can replace my XT with a new one.
I would question the Pos. connection at this time since the Neg. failed already. If you are careful you can disassemble the XT and remove the sleeve that's left and redo the Pos. terminal also. But I would just get a few new XT90's at your earliest convenience to replace it and have spares.
Regarding the Onyx Lipo, you should be 45c or better. I run min of 50c on all my 4s, 5s and 6s rigs. Generally 25C 6s packs are used for large size Drones. (less expensive and usually lighter).
Enjoy.
 
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To be honest the battery is my beater, if it dies it owes me nothing, it’s really a piece of crap. I run hobbystar 5200 3s’ in series for 6s when I’m driving and they’re great, and they’re 45c. Thanks for the help.
 
Your welcome.
Yeah I have beater Lipos too. I see. BTW, I want to get the 6s Senton. I love SC trucks. My son has an Associated Pro SE 4x4 SC and I don't really like it because It breaks all the time. And is maxed out on 3s. But the chassis cant handle it.
I am torn between the Tekno SCt410 or the Senton. I like building Tekno kits. But the Senton would save me much $$$.
:)
 
The senton is hard to break. I drive the wheels off my trucks and on my senton I’ve only broken the front bumper
 
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