OEM contactors/precharge relay units

[RE3Rotor]

Hi, I am wondering if there are values of using these "Battery Junction Boxes" that are off existing hybrids/EVs. What are the pros and cons?

[Bratitude]

Of course. It’s pre made and test(under its designated conditions) saves on more wiring.
just make sure to use what ever box in spect of the components.

[Kevin Sharpe]

What are the pros and cons?

The contactors may require an economiser circuit.

[Dilbert]

What are the pros and cons?

The contactors may require an economiser circuit.

What’s an economiser circuit?

Do the OEMs run these at coils at full duty or pwm them?

[Bratitude]

What are the pros and cons?

The contactors may require an economiser circuit.

What’s an economiser circuit?

Do the OEMs run these at coils at full duty or pwm them?

It limits the amount of power the contractor coil draws so it doesn’t burn itself up. Some have them built in some don’t. That depends on the manufacture. Tesla’s contractors, for example, need an economiser. Most likely limiting them via pwm. There’s a thread post under fast charging on making a simple economiser for contractors.

[Dilbert]

In the past I’ve just coded this in the pwm routines, bastically a short hit at 100% for a second then drop back to < 50% pwm.

[Dilbert]

The GT86 seems to be using nissan leaf contactors / pre-charge.

[Kevin Sharpe]

Of course. It’s pre made and test(under its designated conditions) saves on more wiring.
just make sure to use what ever box in spect of the components.

The GT86 seems to be using nissan leaf contactors / pre-charge.

The devil is in the detail... it's important to review all the contactor specifications before making a decision... look for break current in particular.

[Kevin Sharpe]

Tesla contactor wiki update;

https://openinverter.org/wiki/Tesla_Model_3_Contactors