openinverter forum

Hey all,
I'm starting to build my contactor box using 2013 Nissan leaf components and have a few questions that I'm sure you guys can answer.
1. What's the purpose of a negative contactor? i see that some Ev systems don't use them? "is this a battery pack safety measure?"

2. Does anyone have a diagram of the factory Aev6501C pre charge relay?

thanks everyone for you input ill be sure to post some picture of the final box design for you guys to take a look!

you beat me to it, I was going to ask this question also, anywho I swear I heard Damien Maguire answer it specifically in one of his videos, and I have spent the last month rewatching them to see if I can find the exact clip, if anyone knows in which video he says it, please help a brother out and provide a linky link

monabuild wrote: ↑Wed Apr 13, 2022 5:25 pm Hey all,
I'm starting to build my contactor box using 2013 Nissan leaf components and have a few questions that I'm sure you guys can answer.
1. What's the purpose of a negative contactor? i see that some Ev systems don't use them? "is this a battery pack safety measure?"

2. Does anyone have a diagram of the factory Aev6501C pre charge relay?

thanks everyone for you input ill be sure to post some picture of the final box design for you guys to take a look!

OEMs want to have battery completely isolated from the vehicle for eventual removal installation. So it makes sense to put DC contactor on each side.
This makes sense for single battery box. However usually DIYs make space where it is available and can have 2 or more battery boxes.
I allready mentioned what happens if front box goes to smoke. It will inevitable fry the cables which will touch the car frame and bang oes the rear pack! This is why i would advise putting one contactor on positive side in front and one on negative most side in the back. Fuse i would put in the middle of the positive line between packs. That way unfortunate event in front would not cause total loss on both sides.