Recent content by RealPolarBear

Yup, literally just color. In my mind this will help me differentiate between the two different functions: one enabling the precharge circuit, the other operating the contactor. Ha, that is fair. I figured I mind as well order it all from one place for simplicity.

Alright so I've been working on incorporating everyone's feedback and I believe I have come up with a pre-charge contactor circuit that will work for me. Parts have been ordered. :D For those curious about the components, they are as follows: 72V Coil Contactor 72V SPST Switch 72V SPST Switch...

Alright so an update for my wiring diagram. I have made a rough outline of what I think it should look like based what I have gathered so far. I will try to gather a list of components tomorrow. Any input or critiques of this diagram would be appreciated!

Haha, my head is spinning trying to imagine how everything can be safely wired together. For reference, I was thinking about using this contactor (TE Tyco Kilovac LEV200 72V 500A Sealed Contactor) so that I would not have to power the contactor from an external 12v DC/DC converter. How would...

I think the synthesis that I have come to is that for safety reasons, I would still like to use a combination of a properly sized fuse and a 72v coil contactor. I do not think I really need a precharge circuit, but I may still add it just as another precaution. Better safe than sorry. The only...

Ha, for some reason, @harrisonpatm and @Dui ni shuo de dui 's comments. They hadn't loaded. Both of you make some interesting points that are definitely worth considering. My ideal circuit is uncomplicated but safe and reliable. I would be okay with having two physical key switches. One is...

Thank you for all the information, it has been extremely helpful! The only thing that I would like to add to my circuit for peace of mind is an extra switch for battery power. As of right now, I just have a key switch used to turn my controller on. It would be nice to have an extra kill switch...

Gotcha, the remote idea is definitely worth looking into. Likewise for “Great Scott” haha. Thank you!

Yeah I realize that. I’m hoping that it will suffice for my requirements. I figure I can always upgrade it later if I am not satisfied. I think the em260s uses the same wiring harness too which would be convenient.

Gotcha, I have a DC/DC converter which is already apart of the wiring harness that was provided with my shipment from QS. It is hard to be able to test if it actually works without having the full 72V battery so it may be wise to wait for that before I continue more testing. Thank you for all...

Wow thank you for the descriptive response! I really appreciate you taking the time to help me understand some of these concepts. I think one of the main reasons I'm confused is because of the contactor. I don't quite get how I would trigger the contactor. I'm confused where the 12v power comes...

Hi Sphere! I've been hard at work fabricating a lot of the parts I've needed for my build and I am now at the point where I need to worry about electrical. For background, I have: Controller: SiAECOSYS/VOTOL Programmable EM200-2sp 72V 600A Controller Motor: QSMOTOR 138 4000W V3 Mid Drive Motor...

That's super sweet! It's nice to have the input from some more similar setups. I'd love to see a picture of that build 😁

Also realizing now this thread may have been better suited for the builds thread. Can any admins help with moving this?

Yeah, I think the conclusion I've come to is that a burst of 50-60 mph (80-100 kph) would suffice for me. Any more than that for an extended period of time would drain my battery quick. If my normal riding style is around 45 mph (72 kph) on flat terrain, I think the qs138 4000w v3 is a solid...