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Common high current connectors - and my opinion on them

Posted: May 30 2007 11:36pm
by patrick_mahoney
Commonly used connectors are:
Dean's Ultras - They are polarized (positive can only go to positive, neg only to neg), have an 80A current limit, and make a very solid connection. They can be difficult to unplug though, the female end of the connectors (used on battery end) are shielded, but the male connector is not.
http://www.wsdeans.com/products/plugs/ultra_plug.html

Astro Flight Zero Loss: Polarized, 50A current limit. Make a solid connection. Both male and female ends are shielded. But they are expensive.
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LX3604

Kavan Gold "Stecker" Connectors: Polarized, 75A limit, make a solid connection, both male and female are shielded. Easier to separate than Deans, but not going to fall off. But they are expensive.
http://www.hobby-lobby.com/connectors.htm (mid-way on the page)

E-Flite EC3: Polarized, 60A limit, make a solid connection, both male and female are shielded. Relatively easy to separate, but unlikely to disconnect by themselves. Reasonably cheap.
http://www.e-fliterc.com/Products/Defau ... =EFLAEC303

Anderson Powerpoles: One of the most popular connectors. Polarized, both male and female shielded, there is no specific male and female side, have a 15-180A limit depending on the model. Now that patent has expired, getting increasingly cheaper. On larger plugs can sometimes become difficult to separate(which is both good and bad).
http://www.andersonpower.com/products/s ... rpole.html

Tamiya connector (often called a "standard connector" in the electric R/C world): Polarized, 20A limit, both male and female plug shielded. Individual connectors loosen in the plug over time and doesn't make a solid connection always. Can be difficult to separate (plastic is slippery)... and yet, occasionally will separate by themselves. Usually cheap.
http://www.e-clec-tech.com/tacosetm.html

Molex connector: polarized, both male and female shielded. Suffers from similar problems as tamiyas. Usually very cheap.
http://en.wikipedia.org/wiki/Molex_connector



For what it's worth, at one time or another, I have personally used every one of these connector types. Of the list, I normally use Dean's and E-Flite EC3's... but that's because a local store sells them fairly cheaply. Without my local store, I'd probably be using Anderson's Powerpoles. I personally would recommend that E-vehicle users avoid Tamiya and Molex connectors. I've had them fail on me.

Posted: May 30 2007 11:52pm
by gwsaltspring
I have only had experience with the Anderson Powerpoles, so thanks for the heads up on Dean's and E-flite.

From what I can remember, their pricing seems high compared to the Anderson's.

Greg

Posted: May 31 2007 12:49am
by CGameProgrammer
I have 50-amp Anderson Powerpoles connecting the battery pack to the controller, and while they can get very difficult to disconnect, it's really easy if you just stick a thin object (like a very small Allen wrench) into the holes in the connector and pull on it. So I still like the powerpoles.

EDIT: You didn't mention this, but a unique advantage of the Andersons is there are no male or female ends; there's only one.

Posted: May 31 2007 1:05am
by maxwell
As you have probaby noticed I use mil spec (62GB,38999) type connectors, very expensive, I have a small stash from a previous job. They are so over engineered a nominal 15A pin will happily take 50A at normal temperatures and they make a tidy job. The big problem is once used you never look back.

Posted: May 31 2007 8:41am
by TylerDurden
I use flat 4-pole trailer connectors. 2 poles for pos., two poles for neg.

Color coding not needed, won't connect in rev. polarity.

Image


walmart $5


:D

Posted: May 31 2007 2:14pm
by silentflight
Patrick, Thanks for such a useful post.

Maxwell, Could you provide photos or a link so the rest of us can see?

Posted: May 31 2007 2:17pm
by maxwell

Posted: May 31 2007 2:45pm
by Eric G
Tyler...I've been using the flat two pole trailer connectors for a while now.I like your idea of using the 4 pole ones thus doubling up on the wire,cool.

Can't seem to find Andersons connectors here where I live...

Eric

Posted: May 31 2007 3:45pm
by Ypedal
I order my andersons online, delivered to my door.

I don't understand the part about having a hard time taking them apart ? They do snap together, but i have never had a problem pulling them apart before ??? If crimped properly and snapped all the way into their housings, they are as easy to snap in as out in my experience.

Posted: May 31 2007 4:47pm
by scottclarke
Ypedal wrote:I order my andersons online, delivered to my door.

I don't understand the part about having a hard time taking them apart ? They do snap together, but i have never had a problem pulling them apart before ??? If crimped properly and snapped all the way into their housings, they are as easy to snap in as out in my experience.
SNAP!

Indeed - I don't understand the hard to open comment either. I did however once experience a 2 way powerpole on a mower - THAT was TIGHT! I never did figure out why - once seperated it was as it should have been. Maybe the contacts had welded a bit or something!

I think its worth noting here - controllers with big caps and marginally rated connectors - over time - don't mix well. The arcing on connection eventually mucks up the already marginal contact area - increasing the resistance past 'safe'. Of course - we know the way around this but how many have actually modded the wiring?

As for molex - I have used them as charge ports on my packs for a couple of years. They seem to be ok for a couple of hundred connects then get iffy. I've had only half a pack charged on more than one occasion - sure spoils the ride!

Scott

Scott

Posted: May 31 2007 5:15pm
by CGameProgrammer
Small Anderson connectors are very easy to remove, but the 50-amp multipole ones are pretty large, and I found that after using them for a while, they became hard to separate. Possibly the current slightly heats and expands the metal? I don't know. All I know is eventually it got to where I couldn't remove them without tools.

Posted: May 31 2007 5:48pm
by patrick_mahoney
I've only ever used the large 45A powerpoles, and it's been my experience that on some plugs they just got close to impossible to separate over time. They'd be a snug fit initially but after a couple of months of use, I'd put on gloves and pull... Finally I'd get a pair of pliers to separate them. As GameProgrammer mentioned, I'm not sure why this happens. But it's happened enough to me (perhaps 3 sets of plugs out of 8 ) that I thought that I'd mention it.

Posted: May 31 2007 5:54pm
by scottclarke
patrick_mahoney wrote:I've only ever used the large 45A powerpoles, and it's been my experience that on some plugs they just got close to impossible to separate over time. They'd be a snug fit initially but after a couple of months of use, I'd put on gloves and pull... Finally I'd get a pair of pliers to separate them. As GameProgrammer mentioned, I'm not sure why this happens. But it's happened enough to me (perhaps 3 sets of plugs out of 8) that I thought that I'd mention it.
Patrick,

In my experience this goes hand in hand with arcing on connection - causing a rough patch on the terminals. There may be another mechanism behind it of course....

Posted: May 31 2007 7:51pm
by patrick_mahoney
scottclarke wrote: Patrick,
In my experience this goes hand in hand with arcing on connection - causing a rough patch on the terminals. There may be another mechanism behind it of course....
The terminals arc with a very loud "POP!" that you can hear from a distance when I hook the controller up to the battery. So your diagnosis is probably correct... but I wouldn't think that there's much I can do about it. After having to cut off a couple of 45A powerpoles - and I get nervous soldering on new battery terminals - I gave up and switched to EC3's primarily... which have been easy to swap on and off but don't seem have become loose yet.

Now I use Deans on the headlight connections and on my R/C airplanes and helicopters, and the EC3's on the pair of wiring harnesses for the charger and the bike.

Posted: May 31 2007 9:24pm
by Rassy
I also use the common 2-pole connector made for car and truck trailers. Unlike the common 4-pole connector, they come with either light (maybe 14 or 16 gauge) or heavy duty wire (10 gauge). Wilderness energy uses this style connector to attach the battery to the controller and the controller to the motor. They come already connected to each other (like in Tyler's picture) and can be used as an extension cord right out of the box. I used two when I helped my son put a front hub on his tandem in order to reach the rear rack.

WE also sells a "House Type" breaker for an extra $15 that you can put between the battery and the controller to avoid the spark at the connector. Since I never remove my batteries, I always use a breaker so that it's easy to shut down all power without having to fool around with plugging and unplugging.

Posted: Jun 01 2007 7:46am
by xyster
WE also sells a "House Type" breaker for an extra $15 that you can put between the battery and the controller to avoid the spark at the connector.
I seem to recall that AC-rated breakers don't work properly with DC. Don't know if there's a physical difference beyond how the different types are rated....???

Here's some $10 push-button DC breakers:
http://electricscooterparts.com/circuitbreakers.html
and ~$25 switched DC breakers:
http://www.affordable-solar.com/dc.circuit.breakers.htm

Posted: Jun 01 2007 8:06am
by scottclarke
Just in case this suggestion has been lost I'll repeat it here - and no - I was not the original poster though I do this sort of regularly working on 25KV systems anyway - its a lifesaver then!

Use a small 2 pole connector with inline resistor - connect this first and your caps get charged over a few secs rather than instantly - assuming you have calced the correct value!

Using a seperate switch is ok - and preferable - but if it doesn't close very fast it will wear in the same way as connectors - needing an expensive replacement!

Posted: Jun 01 2007 8:12am
by TylerDurden
scottclarke wrote:Use a small 2 pole connector with inline resistor - connect this first and your caps get charged over a few secs rather than instantly - assuming you have calced the correct value!
Is that just for charging the caps, then the resister is somehow removed?

:?:

Posted: Jun 01 2007 8:18am
by scottclarke
Tyler,

Basically it a seperate lead to the main power feed - connected before the main connector. I (when I used one on the bike) just connected it first and left it on - no harm comes from this since it just duplicates the main connector - albiet with some resistance. Unplugging it once the main is connected is a bit of a pain since you then have a lead to dispose of or tuck away on the bike somewhere.

Posted: Jun 01 2007 8:39am
by TylerDurden
scottclarke wrote:Tyler,

Basically it a seperate lead to the main power feed - connected before the main connector. I (when I used one on the bike) just connected it first and left it on - no harm comes from this since it just duplicates the main connector - albiet with some resistance. Unplugging it once the main is connected is a bit of a pain since you then have a lead to dispose of or tuck away on the bike somewhere.
Got it... connected first, in parallel with the heavy main leads.

:D

Posted: Jun 01 2007 9:45am
by fechter
The big spark you get when you connect the batteries is tough on connectors and switches. Even big ones.

One way around that is to use a precharging circuit. Basically the same thing scottclarke is talking about, but a bit more refined.

Here's the circuit I use on my Vego. I'm using a 24v, 70amp relay from Allelectronics (around $5). The keyswitch gets turned on first, which charges the capacitors in the controller through the 1k resistor. It takes about 5 seconds for the caps to charge. Then I can turn on the kill switch to close the relay, which will only have a few volts across it at that point, minimizing the arcing.

An additional feature of this circuit is if there's a short in the controller (blown FET, etc.), the capacitors won't be able to charge, and the main relay won't be able to close.

Another nice feature is when the keyswitch is off, the controller is completely disconnected from the batteries, minimizing battery drain during storage and reducing the chances of a power line spike getting through the battery charger and zapping the controller (I've heard several reports of this happening, one that resulted in a spontaneous full throttle condition. Imagine your ride suddenly taking off in your living room for no apparent reason :o ).

The 1k resistor should be able to take full battery voltage without overheating. 5w is good for up to about 72v.

The resistor on the relay coil will be necessary if the relay coil is rated for a lower voltage than the battery voltage. The value of resistor is chosen to provide the correct voltage to the relay coil. A 100uf capacitor can be put across the resistor to give an extra boost to pull in the relay, allowing a slightly lower voltage to hold the relay in.

Posted: Jun 01 2007 9:55am
by fechter
The cruder, simpler way to do it is shown below. With the main switch off, the batteries can be connected without a big spark. The resistor will charge up the caps in the controller and prevent arcing on the main switch as well.

In this configuration, the batteries would be slightly drained by the controller when the switch is off, but the drain would be less than the normal "always on" configuration. You could always disconnect the batteries for long term storage.

Posted: Jun 01 2007 10:34am
by Rassy
I don't know what the ratings are on the breakers I got from WE, as there is no information printed on them. I would guess they must be rated for DC since WE supplies them for that purpose. I just called them "house type" because of their design.

Posted: Jun 08 2007 7:13pm
by Beagle123
Thanks for the info patrick. I"m going to get some of those connectors. I really appreciate that you provided the links.

I have another question about connectors:

I bought this controller:

http://tncscooters.com/product.php?sku=101210

it has a bunch of connectors attached to it. Does anyone know where to find the corresponding connectors for these?

Last time I just used wirenuts.


Posted: Jun 08 2007 7:41pm
by scottclarke
No idea where you might find some not already attached to something!

In any case - you are best to hard wire (solder) all the LV stuff like brake cut off and 'power up' since wet weather and open connectors don't mix well!

I have a couple of those controllers btw...

Scott