Pics of your HV junction contactor box

[zippy500]

So I at a point where I would like to start on the HV junction contactor box.

I have tried looking through the posts for layout ideas, not having much luck.

Can you post a pic of your HV junction contactor box in your build.

I have a blank canvas now so want to get it right .

My setup is/will be a Leaf EM57 with invertor.
Leaf contactor box
Zombie
ISA shunt
Outlander charger ( position not decided yet , may go under back seat or boot area)
still have to make battery boxes

I bought a Industrial connection box, But it too big

I also have the base (has been stripped apart) of the leaf PDM , though have to make a Perspex/Ali lid for it.

[arber333]

The "new" HV / relay box in Mazda MX-3 redesign
Be advised some of the OPs here advised me to redesign the threaded studs that support the copper bars because they protrude out under the box. I tend to agree with them as in the prospect of accident you could end up with HV+ on the car chassis.
Should be redesigned using those rubber sealant blocks with M8 studs.

https://mazdamx3ev.wordpress.com/2024/0 ... ntact-box/

[arber333]

Then there is the Pug...
About the same HV / Relay box.
However i managed to get the brass rails fitted without those threaded rods sticking out of the box.
I use color coded or numbered 0.5mm2 cables. Without a sketch i would totally forget where wiring goes in a week.

https://leafdriveblog.wordpress.com/tag/contact-box/

[johu]

As always to be taken with a grain of salt... It's "flappin around in the breeze". But ensures isolation and strain relief.

[Zieg]

Wow, I love the idea of using the bottom PDM shell. Looks like it would add 100mm to the height of the stack. Still too much for my car, unfortunately.

This is mine, during installation. It was necessarily pretty compact. No shunt (current sensor elsewhere in the pack). Precharge resistor is on the right hand side, precharge relay is on the bottom plane between contactors. Fuses for the charger and DCDC are on the inside wall at the bottom of the photo. Economizer PCB is on the bottom plane between the contactor and the wall, under the fuse block.

[Boxster EV]

If I was doing it again, I’d build inside my stainless battery boxes.

[J0hannes]

I won't assume anything on OP:s special skills, so just commenting on a general level. As this is probably a thread that future builders stumble upon, I don't recommend to use most of these setups above as more than a warning example.

Probably most of these guys know better and that's why there are corners cut (If this hurt, you must know that I'm on to something)

I don't know what's the flair for other guys, but if you don't have a packaging issue, I'd recommend to place the contactors inside the battery box to layer up on the inherent safety by design. Meaning you have a full metal enclosure with isolated HV+ and HV - connection points put of it.

I mean just look at how the OEM battery box is made and mimic the design.

There are some really good points in the wiki

A battery box with contactors before output (=HV connection to outside of the box) and a service disconnect to split the pack voltage will increase the probability of ending up with a design that is less likely to kill you or the next guy working on the car.

A split pack config needs some brain power to be used when designing, but you can make it also close to non lethal too.

[arber333]

@zippy500... Well darn! Now you are back to square one....

Whatever you decide it should be your decision. Most of the time all of those applications are OK... untill something goes wrong.
Then you need to be able to quickly react and pull the HV disconnect and shutoff 12V.

But with DIY... what could possibly go wrong?

[johu]

Closest I could get to those ideals was this (removing the shunt splits pack in half)

And this with the Nissan pack

Why? Because there is simply no room for contactors in the box. At least they follow soon after in the exhaust tunnel. And if you want to work on them you have a possibility to cut pack voltage before them.

In Audi I managed to fit them into the battery box:

[nickyivyca]

In my 914 I have 2 separate battery packs and each has their own set of fuse and contactors to protect the separate packs and keep HV within the enclosure when the car is off, no mid pack disconnects though. Then, in a third box I have the main fuse, precharge relays and resistor (separate contactor controlled by the inverter to complete precharge with), DCDC fuse, and charger fuse/contactor. The main project thread has some background.

[zippy500]

...so this is build thread for beginners too.. as above, I have planned to put a fuse and a manual service disconnect to each battery box if being worked on, as well as the leaf contactor box ontop of the invertor that the zombie will control.

is it introducing more levels of failure points if additional contactors are fitted to each battery box ? are people using a single contactor to each battery box ?

[Bratitude]

I agree that there are some examples here for beginners of what not todo. If you know the rules, break them as you wish, but not knowing your set up is dangerous is not something we should be facilitating!

But there are also some great examples of what to do

is it introducing more levels of failure points if additional contactors are fitted to each battery box ? are people using a single contactor to each battery box ?

Fuse’s at every source that links to the external world, and contactor for each box minimum, to keep the box from being live intill in run mode.

best to minimize the amount of boxes. over 2, I say it’s time to rethink pack layout!

[muehlpower]

A battery box with contactors before output

This corresponds to my design. I have three contactors in the battery box, the BMS, the main fuse and an ISA current sensor, nothing else. Plastic inside, aluminum outside. The low-voltage connections for CAN and the contactors go outside via a molex connector. When the Molex is removed, no high voltage can come out of the box. The main fuse has its own small cover, just like the terminals of the HV cables. The contactors for fast charging are housed in the Tesla GEN3 charger. Additional HV fuses are in the housing of the DC-DC converter. Both only have power when the main contactors are closed.