Which Anderson connectors to use

[Beavinator]

Hello I am currently building a 72 Volt e-bike. The battery I am using is from EV Assemble and is 20Ah. I am changing the wiring on my controller to 10 ga. Which amp rating Anderson Powerpole connectors should I use? I have some 75Amp ones here but they are a little bulky. Would the 45Amp be best?

 

[dogman dan]

Depends on the amps. Don't take 45 amp andersons much past 45 amps. 50 should be ok, but not 80 amps. Same for the wire. 12 guage is ok for 45 amps, but above that you want the bigger wire, which doesn't work so well with the smaller andersons. So if you are going big, you want the 8 guage wires and fat andersons. 10 guage wire should still just be able to shove the insulation into the housings of 45 amp andersons, just barely.

Other than the bulk though, bigger is always better.

 

[amberwolf]

Having used the 45-size ones and some much larger 50/60A Multipoles, I most definitely prefer the secure and cool connections of the physically larger Multipoles (which are around the same size as a pair of 75A Powerpoles). I am only running 20A, but can feel the warmth of the 45A-sized housings after a ride, and don't much like it.

I can see a few reasons why some people have trouble with melting those, even when not exceeding their current limits. Using the larger housings/contacts should significantly reduce or eliminate all of those particular problems.

So I'd say go for the largest physical connector practical for your setup, both for the physical security of the connection (less likely to come unplugged by accident) and for the electrical security of not worrying about melting connector housings/etc.

 

[Beavinator]

Well I talked to Michael at EV Assemble and he said my bms is going to be good for 50Amps continuous so I am unsure if the 45 amp connectors will be good.

 

[El_Steak]

Use the PP75 and be worry free.

I'm currently rewiring my pack with 8AWG and PP75. The smaller PP45 I've used up to now get pretty hot on my bike.

But you're right, those PP75 are huge!

 

[dogman dan]

Well yeah, I would too with a methods 100 amp controller.

 

[El_Steak]

Well yeah, I would too with a methods 100 amp controller.

pfff, it's software limited to 80 amps (battery side)

Seriously, the controller may me 100amps capable, but the motor will only ask for that for a few seconds under hard acceleration from a stand still (if you can manage to keep the front wheel on the ground).

Even going up a very steep hill at WOT it will stabilize quickly to around 60 amps. That's with a 9c 9x7, with my previous 10x6, it was hungry for significantly more amps. It was unusuable at 100V though because it was getting way too hot way too fast.

BTW, I like your new avatar!

 

[auraslip]

I'm taking this as an opportunity to bitch about andersons.



Unless you buy the crimping tool 45 amp andersons are almost impossible to crimp correctly.

Sure you can try, but you'll waste a bunch of contacts and time trying. When you do get one that works, it'll be a nasty connection.

I don't really have any advice for other connectors, but just know that andersons are expensive to start with (50 cents each) and you have to buy a $40 tool to make reliable crimps.

 

[dogman dan]

I crimp andersons with a cheapie crimping tool, but yes, it has to be done just a certain way, or they will either have bad contact, not fit in the housing, or both. They can always be soldered of course. For the numbers I'm doing nowdays, I should have the special crimper though.

 

[BIG BEAM]

How come you guys don't solder?Back in my old R/C days all we did was hard wire,even the batteries.Just break out the old Weller and some good 4% silver solder and have at it But back then a good battery was a Sanyo 1400SCR.
DON

 

[dogman dan]

Cuz I can crimp while kicking back watching tv and do a pile of andersons quite quickly. While I find soldering anything about as hard to do as Auraslip finds crimping.

 

[auraslip]

like your new avatar dogman

also you still have to crimp the contact correctly for them to fit into the housing.

14 gauge wire with 35 amp contacts is relatively easy. 10 gauge wire with 45 amp contacts is impossible.

 

[BIG BEAM]

Didn't know that,I use 4mm bullet.If I remember anderson connectors look just like an old connector that some used in R/C called lite speed.

Dogman you don't have a tv in your man cave?
DON

 

[auraslip]

uhhhhhg

The main andersons I use to plug and unplug my ping pack.....I did a shit job of crimping them.....45 amp and 10 gauge wire!

The housing has started to melt because the connection is so poor!

It's been cutting off when I ride...major pain...

ordering the crimping tool and more connectors right now!

 

[dogman dan]

Here in the desert, the man cave, (garage) is often about 120F inside. Because my back is trashed, I pretty much have to get lying down by early afternoon most days. So the bedroom is where I do a lot of working on wiring harness stuff, lying in front of the tv.

Ripped the avatar from the motorized bicycle forum, in the add attachments section. They have a bunch of animated smileys there.

Crimping a 10 guage wire on a 45 amp anderson IS hard, and might even require taking off a few strands. One reason to buy the contacts 50 at a time. Fortunately, 12 guage is big enough even for my racing bike, with the controller I'm using now at 100v.

 

[El_Steak]

Here's how I do mine without the crimp tool:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=18238

BTW, the wire is Hobbyking silicone 10AWG. Noodle like flexibility !

I always finish the job wit a bit of solder though.

 

[Beavinator]

I have the 40 dollar anderson crimper so Ill be fine

 

[Alan B]

The "real" Anderson crimpers are about $160 last time I checked, and they only do 2 of the 3 sizes of the 15/30/45 amp units.

I've been using Powerpoles for a long time in the Ham Radio hobby.

I spent quite a bit of time talking with the Anderson West Coast Sales Manager a few years ago at a Ham Radio convention and I learned a few things from him.

Before West Mountain Radio came out with the excellent "low cost" $50 crimper we searched for crimpers that would work, and we soldered them, and fought with them to keep the tube small enough and round enough to seat in the body.

I wanted to get a real Anderson crimper, but the cost and the fact that it would not do all three pin sizes turned me off, so I soldered them for the most part. And they worked fine. Ham Radio applications generally run 25 amps peak and things are not so critical at that current level.

The Powerpole pins DEPEND on being able to move and be brought into full contact by the stainless steel springs in the housings. If you are planning to run anything like 45 amps the pins MUST be free to move and self align.

Anderson does NOT RECOMMEND SOLDERING. The soldering stiffens the wire and impedes the proper motion of the pin. I have seen many failures on this board from this problem. Even a short loop of heavy wire will interfere with the pin self alignment. If the pins get hot then they are not working properly. Either too much current or improper contact. They will fail over time, probably at the worst possible moment.

I use some of the 50 amp two pin Anderson connectors. They are not Powerpoles, it is a single plastic body and quite a bit smaller than the 75A Powerpoles. They have various sizes. If you compare the resistance specs for the 50A 2 pin connectors they are SIGNIFICANTLY lower than the 15/30/45A Powerpoles. As others have mentioned here, DO NOT EXCEED 50A on the 15/30/45A Powerpoles.

I plan to use the 50A 2 pin connectors on my build for the battery to controller connection. As I recall they can easily handle 100A for awhile. They have a lot more margin and will handle a much larger conductor (#6 AWG as I recall).

There are accessory jaws for the West Mountain Radio crimper to handle the #6 pins on the 50A connectors.

With all the vibration and flexing in a e-bike, properly crimped connections are less likely to fail than soldered connections that concentrate the force on the end of the soldered portion and add leverage to the connection. At least on the large wires.

The Powerpole pins must be undistorted and free to move about in the connector body for the proper tension to be maintained on the mating contact surfaces. Also, the silver plated ones are a bit better than the tinned parts. Silver is a bit better for this application, especially if there is any corrosion or moisture to contend with.

 

[amberwolf]

I use some of the 50 amp two pin Anderson connectors. They are not Powerpoles, it is a single plastic body and quite a bit smaller than the 75A Powerpoles.

That sounds like the Multipole 2-pin version (like I use on CrazyBike2 and The Velcro Eclipse, and like I had on DayGlo Avenger until recently).

They have various sizes. If you compare the resistance specs for the 50A 2 pin connectors they are SIGNIFICANTLY lower than the 15/30/45A Powerpoles.

I'd vouch for that, based on my comparisons of the two on DGA with otherwise identical wiring, battery, controller, motor, etc.

They are also physically more secure in their connection than even 6 of the 45A-sized Powerpoles; the contact detent force is enough that it requires two hands to pull them apart, or one being bolted down to the frame.

I plan to use the 50A 2 pin connectors on my build for the battery to controller connection. As I recall they can easily handle 100A for awhile.

And over 153A for a second or two, as I found during one mechanical failure on CrazyBIke2.

 

[Alan B]

The two pin connectors I use for higher current are Anderson SB 50's. They also have higher current versions. They are the type of connector generally seen on electric forklifts for the charge connection (though generally a size larger than 50A).

I got my SB 50's from dcpwr.com as I recall. They have the 50, 175 and 350 amp sizes as well as the usual 15/30/45 and the WMR crimp tool and various dies. They also have various colored housings for the 15/30/45 and 75 amp pins so you can color code things. Looks like they have just black and gray for the SB 50A connector bodies.

With the SB connectors there is a lot more room for the crimp/solder connection so you don't have problems getting things to fit. As was also mentioned the retention force is larger - they stay plugged in well but are not difficult to unplug.

I think the SB 50 is a good choice for a battery connector, but for the phase wires the current is higher and three connections are needed, so perhaps there a 75A Powerpole is a good choice for controllers over 30 or 40 amps. If that connector is near the motor it is an opportunity to run heavier wire from the controller to that point, at least.

I see that powerwerx.com has come up with their own crimper (and pushed the tool prices down a bit), so there are two products on the market that are slightly incompatible at the die level. The westmountainradio.com crimper and the powerwerx tri-crimper. I have the West Mountain Radio one (for many years) and have not tried the Powerwerx model. I have bought stuff from all three outfits and all are good. They are all involved in the Ham Radio business and come to many conventions. West Mountain gives classes at some conferences on how to install and use the Powerpoles.

 

[auraslip]

I think the SB 50 is a good choice for a battery connector, but for the phase wires the current is higher and three connections are needed,

Really? That seems backwards....since there are three wires you'd think the total electrons flowing through each would be a third of the total flowing through the battery cables.

 

[amberwolf]

higher current are Anderson SB 50's. They also have higher current versions. They are the type of connector generally seen on electric forklifts for the charge connection (though generally a size larger than 50A).

THey are also used in UPSs and powerchairs.

Looks like they have just black and gray for the SB 50A connector bodies.

Those are the two interchangeable colors; the rest are keyed by color so they can't fit into each other (unless you cut the keys out). Often they are used for different voltages.

FWIW, Anderson makes those Multipole shells with three (or even more) contacts per shell, if you wanna use them for phases, too. And you can use the larger sizes if you like, for lots more current.

Really? That seems backwards....since there are three wires you'd think the total electrons flowing through each would be a third of the total flowing through the battery cables.

Well, it depends on the motor speed and the throttle setting, and any current-limiting going on. Basically, as long as PWM switching is happening, voltage is being sent from 0 to pack voltage over and over again, on every phase, as the motor spins, for some percentage of time. Each time that goes back to zero, currents flowing in the motor change (but the motor tries to resist this) and the voltage drops, until the next pulse. Each time the pulse comes back (voltage rises), currents flow again, and they are multiplied

Sorry, had to run while was typing up the above; dogs were way too rowdy and noisy at the fence outside (stray dogs out in the street aggravating them). Can't remember what I was going to say now.

 

[Alan B]

I think the SB 50 is a good choice for a battery connector, but for the phase wires the current is higher and three connections are needed,

Really? That seems backwards....since there are three wires you'd think the total electrons flowing through each would be a third of the total flowing through the battery cables.

There's a little more going on in this case.

When the motor is in the PWM phase (at low speed) the controller acts as a power converter. It is taking power in at the battery voltage and current limit and converting it to the lower voltage the motor is requiring. This conversion increases the current between the flyback diodes in the FETs and the inductance in the motor over what is being drawn from the battery. Current flows there even when the FET path to the battery is switched off. The additional current is generated by the collapsing magnetic field in the inductor, so the load current exceeds the supply current. This amplification is maximum when the motor speed is lowest and the PWM duty cycle is low and it stops when the PWM gets to 100% duty cycle.

 

[auraslip]

When the motor is in the PWM phase (at low speed) the controller acts as a power converter. It is taking power in at the battery voltage and current limit and converting it to the lower voltage the motor is requiring. This conversion increases the current between the flyback diodes in the FETs and the inductance in the motor over what is being drawn from the battery. Current flows there even when the FET path to the battery is switched off. The additional current is generated by the collapsing magnetic field in the inductor, so the load current exceeds the supply current. This amplification is maximum when the motor speed is lowest and the PWM duty cycle is low and it stops when the PWM gets to 100% duty cycle.

I won't pretend to fully understand that. But what i did get was that; phase cable current is higher than battery current.
But now that is interesting, because it means we should be using higher rated andersons.

But the high current PWM isn't always on. Only 1/3 of the time. So for heat reasons you could divide current by 3 and then add the current the motor generates on it's own?

 

[amberwolf]

But the high current PWM isn't always on. Only 1/3 of the time. So for heat reasons you could divide current by 3 and then add the current the motor generates on it's own?

Actually, 2/3 of the time, because it has to use two phase legs to flow current thru at any time; it's just going the opposite way in one of them than it does during it's "turn" in the cycle.

Only one of them is ever "off" at any one time.