Anyone else accidently/stupidly shorting their connectors?

EdwardNY

1 kW
Joined
Aug 30, 2012
Messages
317
Location
New York
I feel like an idiot, I try and be so careful when building all my wiring, but what I seem to always do is accidently shorting my connections.

My wiring is sound it is just doing stupid stuff like plugging them in backwards, plugging two wires that shouldn't be plugged together like two batteries, touching connectors that don't have a housing on yet. I even plugged in balance wires together while the batteries were still connected in series, lucky I only burnt my extension wires.

I must have shorted over 10 connectors since I started this ebike hobby. Just today I got my rear air shock back from being repaired, I spent all day yesterday building my bike stronger, placing batteries better, looking forward to seeing if my air shock would be fixed. While plugging my batteries in series, I accidently plugged in two battery wire harnesses together and poof just destroyed two 6mm bullet connectors. I thought I was plugging my wires into my series connector and plugged two battery wires harnesses together.

I swore to be more careful when plugging everything in, I always do after every accidental shorting, only to later almost short another connector I had to resolder by touching the positive and negative connectors that I had yet to but the plastic housing on. I was extremely lucky and not sure how they did not touch each other.

It is like I just do not think when plugging stuff together, I just do it and then poof as I accidently shouldn't have done that. The problem is I obviously just don't take a few seconds and think about what I'm plugging in. Very stupid I know, but when you are always plugging and unplugging connections you just sort of daydream while doing it after a while. There are so many connectors to plug together that with enough time you will eventually do something stupid.

I am wondering if anyone will also admit to shorting lots of their connectors? Or am I the only person who seems to always do this? I am thinking about devising something like numbering all my connectors this way I match numbers up before plugging them in.
 
Weve done it so often when we started out I think Methods came up with KFF or Kentucky Fried Finger, so yes we've all done it :)

-Mike
 
I am a fan of the XT60 and XT90 connectors. They are double shielded in case a wire end is dropped or touches a conductive surface, plus they are polarized so you cannot plug them in backwards. Cheap from hobbyking. I rotate the pins so the solder cups face upwards, and they are VERY easy to solder to, and also to heat shrink. There is a recess so the heat-shrink goes into the base of the connector, no bare wire exposed...

http://www.hobbyking.com/hobbyking/...0_Connectors_Male_Female_5_pairs_GENUINE.html
http://www.hobbyking.com/hobbyking/store/__24707__Nylon_XT90_Connectors_Male_Female_5_pairs_.html

24707.jpg
 
spinningmagnets said:
I am a fan of the XT60 and XT90 connectors. They are double shielded in case a wire end is dropped or touches a conductive surface, plus they are polarized so you cannot plug them in backwards. Cheap from hobbyking

I like the EC3 and EC5 connectors for the same reasons. I've made up my pack harnesses so I can just plug everything that fits without looking and it will be ok as all the disallowed combinations are physically ... disallowed.
 
Good points. Those bullet connectors can be plugged in backwards. I should look at other connectors. I do use an ec5 and can see how you can not plug them in backwards.
 
Does color coding help? Perhaps even something as simple as a permanent marker and drawing various lines on things to signify good or bad or matching and not matching might help. Maybe, an orientation color matching system. Something like blue is for bottom, and you draw two lines or a few dots on the bottom of two connectors that attach to each other. I am just pulling stuff out of no where, I don't know what would help other than focus for sure. Some connectors look a little unclear to me, some look very clear and even impossible to screw up. I prefer as much fool proofing as possible, we all have our spacey moments.
 
Not yet.

IMO engineer out the problem rather than relying on memory or colour coding. Fully insulated connectors are a no-brainer :)
 
that is right
engineer problem,use plug which cannot be plugged backwards.
If they can be plug both ways, there are NOT belong to ebike.
 
spinningmagnets said:
I am a fan of the XT60 and XT90 connectors. They are double shielded in case a wire end is dropped or touches a conductive surface, plus they are polarized so you cannot plug them in backwards. Cheap from hobbyking. I rotate the pins so the solder cups face upwards, and they are VERY easy to solder to, and also to heat shrink. There is a recess so the heat-shrink goes into the base of the connector, no bare wire exposed...

http://www.hobbyking.com/hobbyking/...0_Connectors_Male_Female_5_pairs_GENUINE.html
http://www.hobbyking.com/hobbyking/store/__24707__Nylon_XT90_Connectors_Male_Female_5_pairs_.html

24707.jpg

Im a fan too, though ive stuck with bullets since they let me series up my packs without the need for extra plugs (just directly seiriesing one pack to the next).

As to the op, yep... Done it a couple of times, though only once with the main leads. Amasing how that much metal can be vaporised huh? My most recent sxrewup involved me having a small short on one of my bslance boards, that i stupidly left comnected (was a verry small short, like 100ish ohms so didnt show up on a ohm meters beep test) to the battery, which now has a 0v cell. :shock: :oops:
 
We've all done it some, or nearly all of us.

I did lots of absentminded stuff at first. I melted down 2 chargers mixing up polarity on them, and then plugging in. It was pretty dumb too, like check polarity with voltmeter, then proceed to mix up the wires and install the plug bacwards.

Gradually procedures emerged that prevented repeated mistakes. Check polarity, attach connectors, check polarity again, is one. Just the other day I was making some odd lipo cells from packs with a bad cell into a 1s 3p pack. After assembly and attaching red and black Anderson housings, I routinely checked the polarity. Sure enough, backwards.

YUP, still a dumbass. But my now habitual routine of one last check saved me a kff.

When assembling batteries, I try to do it in the same way every single time, and part of the routine is taking the time to be sure that series connection is made between two different batteries, not between + and - of the same one.

Sometimes though, I can't seem to save myself from being stupid. I just fried a paraboard last week. I plugged in some packs to it, but the main leads to the charger were not plugged in yet. The bare male prongs touched, and bingo, a nice spark that killed the board.

YUP still a dumbass. Rule one is never have + and - both bare at the same time. I know this rule. I just failed to notice I was breaking it.
 
My most common error is trying to plug in the balance connector on LiPO upside down when using the balance charger. Bam! Probably done that three or four times. I've only tried to plug in a bullet plug backwards once. Well, then there was the time I blew up a charger because I put a bullet connector on a charging harness polarized backward because I had the leads plugged into my volt meter bass-akwards. So yes, I'd say I have done this.

Someone already commented that the best thing was to set up so there is a minimum of plugging and unplugging. I'd second that emotion.

PS: I have used the XT series connectors but I have found that if my hand is sweaty, I have a devil of a time disconnecting them. But, yeah, they are harder to get together backward. On the other hand, you can get them close enough to arc if I am not mistaken. The terminals are right at the end of the housing, I think. I have gone to all bullet connectors, but I do use the polarized housings and that helps a good deal.
 
I accidentally plugged two different chemistry battery packs into each other one time. I didn't have a switch installed at the time so I would have to stop and get off the bike to change battery packs. I plugged an SLA pack into a lithium ion pack. The lithium had a key switch and when I turned it on I heard a rumbling noise and realized what I had done. The SLA was fine but it killed the lithium. The connectors were of course all the same type and right next to each other and I hadn't done a good enough job of keeping them separated. Luckily I had enough power in the SLA to get home.

One of my connectors between the motor and controller burned apart one time and I somehow managed to partially melt a connector between the battery and controller. Nothing was wired incorrectly, it just happened.
 
Regardless of polarised connections or not you can still series the pack main wires, while the balance taps are all still parallel :oops:
 
The frailties of being human. I am trying not to keep count, though I've had (I think) only two KFFs.

The most damaging are connecting balance taps when I still have the batteries in series by virtue of one rogue connection; makes for an awesome light show: Poof! followed by a show of sparks, then gone... :roll:

More rare were crossing APPs; at least they were color-coded.

Super-rare are crossing series batteries with parallel ones; twice I think - with one occurring whilst "On the Road". Had to break out the knife and cut away the char to resurrect the connection before continuing on down the road. Pretty dang embarrassing :oops:

Probably the stupidest of them all though wasn't a connector short, but trying to debug a controller problem with it plugged in and having the probe slip and cross the rails: Instant vaporization of the probe end, a smoking multimeter, and the complete loss of two FETs.

I try not to think about it.

Better to have more coffee, KF
 
Even though I use both the XT60 and EC5 connectors, I still managed to stupidly short and melt a connector. However, my use of XT60 and EC5 connectors dramatically reduced the chances of this happening to me.

All my lipos have the XT60 male connector. No way that I can create a short AFTER the connector is on. Of course, my last short happened while putting the connector on, and forgetting to temporarily cover the other pole with tape.
 
I had 2 SLA 36V packs. One was 12A and the other 15A. The higher amp pack was quite a few charge cycles beyond it's optimum so I thought it would be holding a charge closer to the 12A. I made an adapter plug and paralleled them through their charge ports; just basic anderson connectors. It seemed to be working okay until my bike suddenly died. I unplugged them from each other and tested them by plugging them individually to the controller. They worked fine so I left one plugged in and rode home. I put them back on their chargers. I went to ride the next day and noticed that one of the chargers was still showing red. I then noticed that the bungee on the pack looked tighter then normal. I opened up the bag, unwrapped the duct tape on the batteries and found that my wiring harness had partially melted. Two of the three batteries were swollen near to bursting while the third looked fine. Apparently the charger was trying to pump 36V into two batteries and I guess it's a good thing I caught it in time.

Now the thing is I know I did the parallel connection right because I was paralleling two packs together. So basically I used 2 of my four connections. As for the other 2, one went to the controller and the other to an electronic desulfator. I'm thinking that when I stacked the batteries on top of each other, I either damaged a couple of harness connections or the packs being pressed together generated more heat than the harness could handle. Luckily I had a 24V 15A pack that I wasn't using so I was able to replace the swollen batteries.
 
I think if you dont make mistakes you will never learn,thats what brought me to endlessphere in the first place,i was bragging about my ebike circa 2006 and plugged in my connectors -improperly- to show off my new ebike and started a stinky mess.i still get teased from that moment,plus i got kff from grabbing anything to stop my meltdown.still making mistakes but can laugh it off now.
 
Yes.

This was say a Monday:

g2.jpg


By around Wednesday my hand had healed up to be hardly sore anymore:
IMG_20120909_212450.jpg


Then, Friday when I was well into healing, and caused another >200vdc arc-flash from being a total tool and botching polarity on the same connection I botched earlier that Monday... And once again vaporized the connecting bits on the ends ends into bits of molten copper that sprayed into my fingernails and newly healing skin...

IMG_20120910_154545.jpg



So to answer your question, Yes, many others, quite likely nearly all of us, have stupidly shorted some connector at some point due to human error. If you want to not have this occur, about the only option that works is to use all non-compatible/keyed connector types so it's not mechanically possible to mate connectors in ways that causes KFF.
 
Regarding connecting packs in series while balance leads are still paralleled: I think this could be avoided by not balance charging packs in parallel.

I.e. parallel the main leads to do your regular charge. Then when you need a balance charge (usually rarely), connect only one pack at a time to the charger.

You're then out of the habit of ever having a situation where this particular short could happen.
 
Yep can vouch for cooking human flesh smells like pork.
 
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