Wow, I've never seen something like this.
I am testing my new setup and have been using some older Batteries which I believe have HK Deans Plugs. I have been flying my Trex 450 with them and never had a problem with these connectors.
I am setting up a SkyFun and it also cam with a HK Deans male connector. The plugs mate fine no problem.
Last week I ordered Deans connectors from DiyDornes.com and soldered them onto the a current Sensor http://www.sparkfun.com/products/9028.
(I assume DYIDrones.com is selling original Deans connectors?!?)
No problems in testing. I did notice that the Female (DYIDRones) connector needs a lot or force to connect to the Male HK connector.
Today I was doing a final test at home before heading top the flight field. I connect the battery HK female to DYI Male and - NOTHING - no power. I check the battery 11.6 V measured with a Volt meter at the deans connector Hmmm --- I take another battery # 2 everything is fine.
I connect Battery # 1 again and leave a ,little room so I can still touch the male connector with my Volt meter tips. NO VOLTAGE. The Connectors are mechanically mated and provide perfect insulation.
I conclude the female (HK) must have an issue. I snap of the plastic of BUT the contacts are flawless - no dirt no corrosion nothing.
I take battery #3 same problem.
I take the current sensor out and connect female (HK) to male (HK) and the problems goes away.
So I have a bunch of incompatible Deans connectors.
This could have easily gone really bad in flight.
What I have learned - Do NOT mix Deans connectors from different vendors best Use something else.
I am going to switch to XT60 unless somebody has a better suggestion!
I hope this post will save somebodies Plane !
Has anybody similar experiences? I'd like to hear!