# Contactors with Tesla motor & battery



## itchyback (May 28, 2014)

So i'm chasing three contactors for using a tesla motor and full 16 modules from a tesla battery (400v). one for precharge, one each for positive and negative battery terminals. 

I dont know what size to get.
I see evtv offer the GIGAVAC GX14BAB for the Tesla module BMS, but it seems a bit too small (350amps), and i dont know if it is publicly known what the continuous current usage of the Tesla motor is.
I was thinking it might be better to get the Gigavac GX16BEB 600 Amp 800v Contactor. 

Do you think the 600amp would be better?
Is it a problem to get a contactor that is too big?
should all three be the same size?

Cheers


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## Kevin Sharpe (Jul 4, 2011)

Where are you based? If you're in the US or Europe then it might be a lot cheaper to buy a Tesla Rear HVJB or Rear Ancillary Module and reuse the contactors, pre charge resistor, connectors, etc., etc.


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## Kevin Sharpe (Jul 4, 2011)

itchyback said:


> So i'm chasing three contactors for using a tesla motor and full 16 modules from a tesla battery (400v). one for precharge, one each for positive and negative battery terminals.


FYI most systems use two contactors not three... the precharge resistor is wired across one of the main contactors.


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## itchyback (May 28, 2014)

Thanks Kevin,
I'm in Australia so conversion rates and postage may make buying those original bits cheaper. 
I bought the whole battery case and kept all the bits inside. I clearly havent looked at them properly, my thoughts are they were OEM and may be more difficult to re-use than to buy something else. whoops :?

I have the pieces from the second two photos. The bits you mentioned, the HVJB and rear ancillary module, which name refers to what you have in the first picture and where is it located in the car? I'll ring the guy who has the car and see if he has it still. They dont know much about them yet so help locating bits is appreciated. 

It makes sense there is only 2 contactors, the instructions i got have three. written by someone smarter than me no doubt so i follow them.

Cheers


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## boekel (Nov 10, 2010)

I think the precharge resistor is switched by the small board-mounted contactor on the BMS master board.
(The above is an uneducated guess, I didn't trace the tracks, just assumed)

If you still have the battery case: carefully remove the bms wires so you can reuse them, some battery packs are easier than others...but it's possible to get the wires out without damage.


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## itchyback (May 28, 2014)

I'll get some garage time in two days. i'll check my bits then.
I have the BMS wires, they were buried within a large amount of glue and wires! difficult to get out bit not impossible.


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