Yamaha YZ450F

[j bjork]

What about the QS12F+M? can be used for 250A and 4AWG.

QS12F+M DONGGUAN QS ELECTRONIC TECH CO.,LTD - Steckverbinder: zur DC-Stromversorgung | Stecker/Buchse; QS; 250A | TME - Elektronik Bauteile Deutschland

DONGGUAN QS ELECTRONIC TECH CO.,LTD QS12F+M | Steckverbinder: zur DC-Stromversorgung; Stecker/Buchse; QS; 250A - Das Produkt ist bei TME erhältlich. Prüfen Sie unser reichhaltiges Angebot.

www.tme.eu

I ordered some qs9 that I might use for the charge port.

It seems like about 20mm2 is max on qs12, that seems a little small for the discharge to me.
But a little big to solder properly
Anyway, at the moment I'm leaning towards trying to make my own contact connector. But it depends on if I can get a strait mounting position, the bend on the battery complicates things.

A late chime in on BMS', the 32S ANT BMS I have is actually pretty good. The app, once you figure out what to install works very well. BT range is good. I haven'r tried talking to it over a serial link yet, but that's kinda what ANT BMS' are all about, so I'm not too worried. +1 for the ant..

The complaint I have about the newer app is mostly why it needs so much info from the phone, like gps etc.
Then it is the problem I have had with 3 bms:es now that they sooner or later starts reading cell 1 wrong

 

[scianiac]

I saw this video awhile ago, the guy is a little interesting but seems to me the actually the QS connectors aren't as much the issue as the wire size and solder connection. I wish there was a similar style of connector, that is giant bullets in a nice plastic housing but with crimped ends. So basically the wire connection sides are long tubes that you crimp around the wire and then snap those into the plastic body. Nothing like a proper hydraulic crimp.

 

[dominik h]

I have a QS10 soldered to 25mm² high flexible wires as fast charging plug.
It is not easy to unplug them, but the Anderson 175A is way bigger.

 

[bananu7]

For the record, got this in the mail recently:



My hands aren't small, it's just this thing is absurd. It's rated at 500A and for once I don't think saying anything about "Chinese amps" applies here. I was surprised that it came with M10 at both ends as well. Still pondering whether it's an overkill and I should downsize to match the M8 on the controller or roll with it and be sure that the battery connectors will never be a limiting factor.

I thought about the quick detach ones I posted but decided against them mostly because I don't own a crimper that would handle securing them to the cable, while regular bolts seemed easy and reliable. I am not planning on unplugging the battery hopefully ever, though.

I'm going to run 1AWG for discharge and 8AWG with the SP29 connector for charge.

 

[j bjork]

I got the QS9 connectors today, those frockers aren't small either

A XT90 for comparison.
There is a 5,2ohm pre charge resistor built in.

Those QS12 connectors are looking more interesting for discharge connectors after I got these
I would like something like this with a mounting flange, but I havent seen that in the bigger connectors I think.
With this pre charge built in I could probably skip the whole contactor business, and just pull and plug in with power in the circuit.
A little less safety in exchange for simplicity..

 

[bananu7]

Do you think QS12 would handle the required currents? Manufacturer statees 250A cont. 320A peak; I know it's at 500V, but at the power you're running, I'd be a bit concerned. Especially given that for QS12 the max wire gauge supported seems to be AWG 4.

I went with this 50A one for the charge port (called WK29), right now I have just a 10A charger, but if I upgrade it will likely be capped by 10A @ 230V anyway, so a 50A connector is more than enough, and I liked how they seal when not in use.

 

[j bjork]

It is a bit weird that they are so low rated for peak current. The continuous rating will be more than enough, but the peak will be a lot higher than the rating. Here they test a qs 8:

If dominik h can fit 25mm2 on the qs 10 I think the qs 12 should take more, maybe 35mm2 with some luck. But I am a little skeptic about soldering these kind of sizes

On the other bike I have andersson 175A and 35mm2 wires, they got slightly warm after the "stubbrace" I rode some time ago. But that was just wot (or as much throttle I could handle) then hard on the brake (regen brake that is+front brake) for maybe 10min races.
But usually they seem close to ambient.
I think these connectors should be able to carry the same amount of current at least. They should have more contact area, but maybe not as good material.
I believe the qs connectors are gold plated brass and the anderssons silver plated copper. Or is it maybe just zink or nickel plated?

 

[j bjork]

Finally my bms:es arrived:

After all the back and forth I eventually just went with ant.
The big one is for this bike, the small is for the old one.

I´m thinking that hopefully I can get the controller and bms to communicate over Bluetooth, but if not it´s not a big deal.
I will just run these as they are, no bypass or modification.
It will be some challenge to fit it in the battery it seems.

 

[j bjork]

The progress has been very slow lately, last update almost a month ago.
And then it wasn't even about building something..
First some more about just buying stuff:

I want a side stand on this bike too, but Im not that impressed with the aftermarket stuff.
So this time I went oem and just bought all the parts.
As usual it wasn't cheap

I got a pair of qs12 connectors today:

They seem better than I hoped
I dont know how they came up with the wire sizes, I tested 35mm2 and it fits just fine.
I wouldn't go smaller, it can probably take bigger. The hole for the wire in the pin is 10mm.

And as you can see you can remove the pins, they are threaded.
That sure makes it a lot more likely that I can solder it properly.
I wonder if that is possible on the smaller ones too?

It has a 15,2ohm pre charge resistor, strange that the qs9 has 5,2ohm.
It has a seal, but I wouldn't call it sealed..
There are gaps and and ridges that it cant seal, so that is mostly for show.

Then I have actually done something on the bike:

The battery box has got a pocket for the bms in the front, it seems like the only reasonable position.
I have an idea of making the battery mostly square, then make cover over it shaped as the gas tank that also holds it in position.

I have spent more time just looking at that damn box than actually building it.

 

[j bjork]

Not much new here, but I have done some pre charge tests:

So, trying to plug it in at a normal speed while not getting electrified
I used a battery from the other bike at 120V, so pretty normal circumstances there.
Seemed to work just fine, I didnt hear any spark or see any traces of arcing in the connector afterwards.

I think I will use this connector, well there is at least one problem left. Soldering 35mm2 wires
One more thing, I would have liked a connector with a mounting flange of some sort.

 

[rour8388]

Hey j bjork
After several months of looking at everyone's topics on the forum for my own project, and especially yours which inspired me a lot, I allow myself to add my two cents on your build. I wonder why you insist on installing connectors on your discharge wires. Why not connect your battery directly to your controller? Do you plan to remove your battery regularly to justify this?

 

[Zambam]

I've been following your thread bjork. Nice work!

I am surprised to see those humongous QS connectors are soldered and not crimped! If you have a momentary short, I'd bet the first thing that lets go are those soldered connections, melting and splattering solder all over. You will never find soldered pins (from smallest to the biggest) on mil-spec connectors, they are all crimped.

 

[j bjork]

The whole point of building the battery like I do, the quick disassembly of the seat etc. is to be able to change battery fast.
I change battery almost every time I ride the other bike, and it will be the same on this one too.
That is also why the built in pre charge resistor is a big thing, I plan to skip the whole contactor thing and plug in the batteries live.
Everything would be a lot easier with a permanently mounted battery, and in that case I probably wouldn't have a connector between the battery and controller.

But there would be a lot less point to build the bike in that case, I could just as well buy a varg.
There is still a few reasons to build it myself I guess, one is to be able to repair, and the biggest reason would be that I had built it myself.. I have always built my own race stuff, it would be embarrassing to show up with a bought bike

Zambam, yes I sure would like them to be crimped. I am not very worried about the solder melting though, the bms should trip long before that happens. If it doesn't I think the fuse will blow before things get hot enough.

 

[rour8388]

I better understand your need if you want to change the battery easily. Considering your discharge currents and to avoid burning the connectors, one solution might be to use two wires per polarity. This would give you one connector for the negative and one for the positive. You would then split your current in half within the connection. Also, a smaller positive connector with your precharge resistor.

 

[j bjork]

That would mean 3 connectors to plug in and out every time I change batteries, that is not quick.
I have 2 connectors on the other bike, so to make it faster on this one I went for max one connector.

I considered something that plugs in automatic when mounting the battery, but I thought it would be too risky that something goes wrong when things are dirty and you are tired and just push the damn thing down when it dosent fit properly.

A good thing with this connector is it has 4 small pins as well, handy if I will need communication with the bms.