Micro Motor Community

Learn from my mistake... Double check polarity, do it again, and one more time for good measure


So I finally got my walkera female cables to make my battery y-connector so I could run FPV setup and FC off the same battery, when catastrophy hits. It turns out the female connecters came wired reverse polarity for some reason, and being the idiot I am, I forgot to check for this… luckily, my pololu voltage regulator acted like a $6 fuse, and the only thing that got damaged was it.

Moral of the story:
Check polarity on the part its connected to, check polarity on the wires, check polarity on the connector, and then do that 2 more times…

(also the reason this is in crash clinic is because it says that it can be “if you released the magic smoke” also)



Many of the batteries for various toys are reversed polarity to what most of us run. You have learnt the hard way, but the hot tip is like you say, always check polarity on a new battery. Several of the hobbyking batteries are like this.



Yeah I have had a reverse polarity battery from HK that almost fucked up my hubsan, but luckily i immediately removed it before anything was damaged and fixed the polarity and it worked great. Now I’m going to always use my multimeter to check things before connecting them (after soldering something new at least) because of this incident.



I learned it the hard way too. As many others here. Me haven’t had a 6$ fuse like you. Glad that saved your FC.



The FC actually got the full force of the reverse polarity, but I guess it doesn’t burn out hubsans :confused: The FPV setup is what got saved by the voltage regulator acting like a fuse.



Ah, too early in the morning here. Just woke up, need some time before my brain is working.
Maybe shouldn’t post before thinking through it, haha.
Anyway, glad you saved everything except for the vreg.
Interesting that FC has survived.

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It’s very late over here in the PT zone. Another reminder of how cool the internet is (connecting people so far away and such)… I bet the reason the FC survived was because I was sorta timid so it was only plugged in for a split second, I could be wrong though.



Hubsan FCs have reverse polarity protection. See:




I actually learned this lesson on mains voltage. My dad was an electrical engineer, and as a teen I would go work with him in the holiday. Long story short, I blew some stuff up and scared the crap out of myself. Been careful cutting wires and connecting them ever since!

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