How to make an XT90 Loop Key

More compact if you ditch all the XT60 connectors and solder everything, unless you take apart your board all the time

cool, yeh i would do if it was more permanent, at this point though i am taking it apart a lot, the idea is to have an easily swappable battery between 2 set ups,
at least until the bank balance levels out and i can buy another battery :wink:

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JB Weld does have actual steel in it. It is definitely very magnetically conductive. It doesnā€™t seem to conduct electricity at low voltages, but I would not count on that. I just tested it (JB Weld 8265-S Original Steel) with the multimeter and no conduction. Itā€™s not steel ā€“ but it has steel powder in it.

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Thanks!
yeh iā€™m gonna not use it if thereā€™s even a slim chance of conduction at higher voltages,
plus it doesnā€™t look as pretty as resin, and with resin i can patch up a few old decks at the same time

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Being snug is really good, and it will get looser with use. Also sometimes I slightly bevel the edges of the plug as seen in this photo on the bottom-left edges

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Iā€™m afraid to tear the cables from the connector with an lanyard :frowning:

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Shouldnā€™t happen. If itā€™s a good solder joint, youā€™re saying that the tensile strength of metal wire isnā€™t comparable to wool/plastic lanyard. As long as itā€™s not razor thin, I think the most youā€™ll risk is cutting the silicone sheathing

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Iā€™ve used the same loopkey for 3 years, 10awg wire loop

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Can you help me figure out why I fried 2 times in a row my XT90S loop key ?

My battery is a 14s3p Samsung 30Q, the loop key is on the positive terminal of the battery.
I fried my loop key (big spark when connecting it, black residue, and now I measure a resistance way higher than 5.6Ī©). I made another one, after 1 or 2 connections, it fried again.

Any idea why ?

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I burnt one by not having the loop key all the way in during a quick test. Smelled it and pulled it out. Next time installed it went pop.

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Not pushing the key all the way in.

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Check the polarity of the XT90 connectors on the battery

@b264 well it wasnā€™t pushed all the way in, but it sparked before letting me a chance to do so :frowning:

@Linny I checked with a multimeter, the polarity is ok

Itā€™s permanently broken because it was operated without being pushed in all the way.

Make a new key. You used the female side for the key, right? (male side on board)

The female side is the one thatā€™s broken.

In the future, make sure you fully insert it, donā€™t just plug it partially in.

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Yes I use the female connector for the key.

Iā€™m pretty sure I pushed it all the way in since I knew it could damage the connector if I didnā€™t.
Iā€™ve made a new loop key which fried too, so Iā€™m trying to figure out whatā€™s going on before killing more connectors :smile:

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It would be interesting if you could make a loop key with a tiny buzzer that would go off until it was fully inserted.

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The only thing that will kill them is being operated while not plugged in all the way.

and using them for 20S voltages (84V)

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AS150 is another option. I used one for quite a while on a board until I popped in an Antispark.

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Is it possible that the black residue on the male connector because of the first spark, prevent the connection with the resistor on the female connector ?

How long does it take to kill while partially connected ? Maybe I plugged it too slow, I really donā€™t know :sweat_smile:

It donā€™t take longā€¦ milli-secondsā€¦ your entire battery power will be flowing through that tiny resistorā€¦

milli-seconds

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