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-   -   8AWG wire to a Deans Connector? (http://www.rcuniverse.com/forum/electric-rc-jets-198/10699951-8awg-wire-deans-connector.html)

BadThumz 09-03-2011 02:06 PM

8AWG wire to a Deans Connector?
 
Getting ready to attached some new LiPo's with 8 gauge wires to a Deans connector. Big wire, small soldering pin. Any new tricks out there? It was suggested I try the Traxxas LiPo connector for cars. The Traxxas connectors are supposed to be wider and longer for an easier soldering job? Anyone try that?

Extreme_RC 09-03-2011 02:29 PM

RE: 8AWG wire to a Deans Connector?
 
5.5mm long or 6mm short bullets, dont even think of using Deans with this weight of wire. Also you need a high quality iron with a big wide tip and at least 60-80 watts, its going to take a few minutes to get the heat right through the wire so you can tin it properly, you need to sweat soak the solder right through the wire first, then fit to your plug and use the heat to sweat the solder right through the whole joint, without a powerful solder station this takes plenty of time so dont be impatient when doing it.

harralk 09-03-2011 02:44 PM

RE: 8AWG wire to a Deans Connector?
 
I agree with Extreme.  Dean's connectors are actually only rated to 60A continuous current with 75A burst.  I know a lot of people run 100A+ through them, but it's NOT recommended.  An electrical engineer friend of mine did an analysis on the Deans and found out what there actual current rating is.  Besides, the contact area of the solder joint diminishes when the wire gauge gets bigger, thus further reducing the connector's current rating.

Just go with bullets.

BadThumz 09-03-2011 06:38 PM

RE: 8AWG wire to a Deans Connector?
 
Shall do. I have Deans on everything but they are just too small for 8 gauge. I'l go with thr 5.5 bullets.

evan-RCU 09-04-2011 03:51 AM

RE: 8AWG wire to a Deans Connector?
 
I disagree. I still use HK clone Deans on everything...


harralk what do you mean... "the contact area of the solder joint diminishes when the wire gauge gets bigger..."

nonstoprc 09-04-2011 04:35 AM

RE: 8AWG wire to a Deans Connector?
 
my 4mm bullets have much more contact area than Deans and the current drawn by the motor is around 85A. Deans probably would work but there will be a power loss at the Deans.

evan-RCU 09-04-2011 05:01 AM

RE: 8AWG wire to a Deans Connector?
 
My HK clone deans don't get warm at 85A or even higher so there can't be too much loss...

nonstoprc 09-04-2011 05:52 AM

RE: 8AWG wire to a Deans Connector?
 
what is the application? I am surprised.

evan-RCU 09-04-2011 01:31 PM

RE: 8AWG wire to a Deans Connector?
 
One is the 16ft span plane in my avatar. 12S, like 4000W, 80-85A. I also have a 12S 700 size helo, some F5D pylon planes, and some hotliners... All with the clone Deans.

BadThumz 09-04-2011 02:13 PM

RE: 8AWG wire to a Deans Connector?
 
I have actually partially melted a Deans. I have learned to keep the male or female plug attached and use it as a heat sink when I solder a Deans.

Extreme_RC 09-04-2011 03:09 PM

RE: 8AWG wire to a Deans Connector?
 
1 Attachment(s)
Connecting deans together when soldering risks distorting the casing as it gets hot, due to the spring pressure against the flat plates.

Deans are NOT recommended on anything above 6s purely for the reason of soft start, how do you soft start when plugging deans together???

Bullets (not banana plugs) have more contact area for both the connection and the soldering point, plus you can add a resistor to the ESC side for soft starting, this helps to save your ESC caps and ultimately your ESC from premature death. Pic attached.

PLUSbullets are far easier to work with on multi pack setups, they simply plug into each other to create series packs, no Y harnesses needed.

I used to use real Deans on a 70E size chipmunk, 6s and 70+ amps, the plugs got warm, wiring was stock ESC length, no extensions. All converted to 5.5mm long bullets now, much easier to deal with and no temp rise.

Lastly, you get what you pay for even with plugs and wire, HK wire is very difficult to solder due to low copper content, its cheap silicon wire, same with the plugs, the machining quality of the cheap plugs vs premium plugs is quite apparent, bad machining = poor contact. Pic attached.

gary41 09-04-2011 03:44 PM

RE: 8AWG wire to a Deans Connector?
 
As an ex-electronic tech, I totally agree with Extreme RC in his recommendations.

evan-RCU 09-04-2011 05:36 PM

RE: 8AWG wire to a Deans Connector?
 
1 Attachment(s)
Same as you do with bullets. Pic attached...

As an electronics tech I think each person should decide what works best for them themselves...


Quote:

ORIGINAL: Extreme_RC

Deans are NOT recommended on anything above 6s purely for the reason of soft start, how do you soft start when plugging deans together???


MaxThrottle 09-05-2011 04:21 PM

RE: 8AWG wire to a Deans Connector?
 
It boggle the mind.... this repeating conversation.... look at the stardard plug you use on your wall. Now look at the 30 or 40amp plug on your stove or dryer. There is a standard of safe operation. Why is it necessary that some must push beyond this .....

Deans explains their connector is only as good as 12 AWG rating and are in the process of making larger connectors. If you are going to 8AWG why use a 12AWG rated connector?

juanjulian 09-05-2011 05:02 PM

RE: 8AWG wire to a Deans Connector?
 
Also with recomendation of Extrem RC.

Liked a lot how he placed the resitor, hope there is no copy right on that idea.

What is your solution for avoiding the possible shorts using bullets as terminal in the batteries?

I´m building a high power 90mm edf from Extreme RC, and discovered after a few minor shorts even being carefull that there is a big chance for the bulltes to short even with heat shrink. For the moment I put some tubing to the male bullet while in storage, but there is a risk while assembling and dissasembling 4 3s packs into a 12s pack.

Bought a parallel harness to charge 4 3s packs at once, and very scared of the high posibility of the leads shorting while disconecting each pack from the harness.

Cheers,

Juan

gary41 09-05-2011 05:14 PM

RE: 8AWG wire to a Deans Connector?
 
You might take a female bullet and shrink 2 or 3 layers of H/S tubing about 1/2 inch longer than the bullet so that the unused "wire end" can be pinched shut. Makes a good "dummy" safety plug.

BadThumz 09-05-2011 05:35 PM

RE: 8AWG wire to a Deans Connector?
 
The "dummy" plug is a good idea!

MaxThrottle 09-05-2011 06:36 PM

RE: 8AWG wire to a Deans Connector?
 
juanjulian; Why not just use a [link=http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=12887]XT150 connector[/link]
These 6mm bullet, not banana connector, can link together if you must setup like a Dean and the casings as well as the bullets are male female and color coded.
So if you are the type to get confused then put male male and or female female casings on the batteries. This will allow you to still series the batteries also.

As for copyright on using a resistor??????? The manufacturer sold it for that intended use?

Extreme_RC 09-06-2011 01:55 AM

RE: 8AWG wire to a Deans Connector?
 
Quote:

ORIGINAL: evan-RCU
As an electronics tech I think each person should decide what works best for them themselves...
An electronics tech would not suggest that someone decide what works best for them, rather he/she would recommend whatis thesafest mostreliable and electrically "correct"product/method for the particular application.

Oh and all that wiring in your picture, harnesses etc, very unnecessary for a series connection, Bullets simplify and improve immensly over cheap HXT T plugs. Any tech will know resistance across additional lengths of wire coupled with masses of extra plugs just robs the system of power. http://www.rcuniverse.com/forum/js/f...wink_smile.gif

nonstoprc 09-06-2011 04:15 AM

RE: 8AWG wire to a Deans Connector?
 
[link=http://www.stefanv.com/rcstuff/qf200001.html]This URL[/link] has good info on the resistance of various types of connectors. If the number on Deans is accurate, then the power loss at 85A will be 85*85*000039 = 2.81w.

Type of Connector Resistance per Connection Power Loss at 20A
Anderson / Sermos / Lightspeed 0.00066 Ω 0.26W
AstroFlight Zero-Loss 0.00048 Ω 0.19W
Deans Ultra Plug 0.00039 Ω 0.16W
Kyosho / Tamiya 0.00652 Ω (see text) 2.61
W


The soldering area for Deans is also smaller than 4mm bullets: one side for Deans, and all-round plus the tip section for 4mm bullets. The total soldering area contributes to the power loss inversely.

MaxThrottle 09-06-2011 06:22 AM

RE: 8AWG wire to a Deans Connector?
 
Using the same source material linked, note the final comment made; "Finally, if you are into really high currents (such as the 60 to 100A encountered in F5B), none of these connectors will be suitable. At 100A, even the best of the surveyed connectors would dissipate about 4W of heat per connection. Most F5B fliers use 4mm gold plugs, with the battery connectors soldered directly onto the first and last cells in the pack. Motor connections are soldered directly. "

Thus 6 and 8mm bullets starting to take their place above 85A and with the added protection of some newer connectors like the XT150, you have both safty and performance advanatages.

ACES&8s 09-06-2011 06:08 PM

RE: 8AWG wire to a Deans Connector?
 
8 awg with a deans is dangerous to fly on. It is not good procedure. Check the current rating on Deans. 74 amp max. Over that the heat melts the solder connection. Immediate loss of power in flight, worse if you lose servo. 8 gauge wire is rated higher than the deans, and will carry plenty enough to melt the solder on a hot gold deans pin. You'll be hard pressed to work it into place anyway.

My Saab used deans on the battery, with some disastrous results, see my vid on tube acecade345 called Saab Story. The deans was found to have melted. The ESC was still good, an 80 amp. The connection had become intermittent and I lost the plane.

In engineering drafting classes and electronics classes we a taught, a simple rule, over-do the rating, by double if possible. For a resistor on a circuit board; if 200 milliamp is going through it and its a 10 ohm resistor, that's 20 milliwatts or .02 watt. a 1/4 watt resistor is ok. For that same resistor with a higher applied voltage, with a current of 2 amps, that is 20 watts. a fixed resistor would pop. somewhere in between say, 100 miliamps and a 10 ohm resistor, the watts is .10 watt. a quarter watt resistor is fine (.25 watt)

If you look at a motor and esc and battery from a power / volts / amps point of view, and keeping in mind, the over-do-it rule of double (for a safe circuit), then any current through that Dean's should be as great or greater than the total current in the system. No Weak Link. If your ESC is 100 amp, the 8 awg can carry over 400 amps and the lipo can supply bursts of 200, and you are connecting them with a 74 amp (fuse), what's going to pop first? Every link should be greater than the total system power.


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