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OEM contactors/precharge relay units

Posted: Mon Mar 02, 2020 9:36 pm
by 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?

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Re: OEM contactors/precharge relay units

Posted: Tue Mar 03, 2020 8:05 am
by 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.

Re: OEM contactors/precharge relay units

Posted: Tue Mar 03, 2020 6:11 pm
by Kevin Sharpe
RE3Rotor wrote: Mon Mar 02, 2020 9:36 pm What are the pros and cons?
The contactors may require an economiser circuit.

Re: OEM contactors/precharge relay units

Posted: Tue Mar 03, 2020 7:31 pm
by Dilbert
Kevin Sharpe wrote: Tue Mar 03, 2020 6:11 pm
RE3Rotor wrote: Mon Mar 02, 2020 9:36 pm 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?

Re: OEM contactors/precharge relay units

Posted: Tue Mar 03, 2020 8:26 pm
by Bratitude
Dilbert wrote: Tue Mar 03, 2020 7:31 pm
Kevin Sharpe wrote: Tue Mar 03, 2020 6:11 pm
RE3Rotor wrote: Mon Mar 02, 2020 9:36 pm 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.

Re: OEM contactors/precharge relay units

Posted: Tue Mar 03, 2020 8:57 pm
by 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.

Re: OEM contactors/precharge relay units

Posted: Tue Mar 03, 2020 11:23 pm
by Dilbert
The GT86 seems to be using nissan leaf contactors / pre-charge.

Re: OEM contactors/precharge relay units

Posted: Sat Mar 07, 2020 9:05 pm
by Kevin Sharpe
Bratitude wrote: Tue Mar 03, 2020 8:05 am 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.
Dilbert wrote: Tue Mar 03, 2020 11:23 pm 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.

Re: OEM contactors/precharge relay units

Posted: Fri May 15, 2020 11:47 am
by Kevin Sharpe