When I charge my car, I usually try to lay out my charging cable so that there are no loops in the cable. That is, no part of the cable touches another part of the cable. I believe the current going into the car is AC, so I imagine there is some (hopefully small) amount of inductance created by any loops in the cable. Does this matter in terms of either charging efficiency or safety?
Do loops in charging cable matter?
- Thread starter tim
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Francofun
Member
Wow! I never considered this and someone will hopefully do the math here (it’s been too long!), but I really doubt there is any measurable effect. The electromagnetic field exists with or without loops. There is or would be shielding in the wire if that would be of any concerns. Besides, might be a bit too optimistic, but I think we would have heard of any issues by now (not just from charging an EV).
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Kerbe
Well-Known Member
Unless you're driving a Clarity EV, the car is not capable of accepting a DC charge so don't worry about that. Actually, don't worry about the whole issue - it's not a problem. If it were, every power cord on every device and appliance in your home would need to be laid-out straight. Chillax!
ClarityBill
Active Member
I felt like I had better luck with the Chargepoint chargers when I laid out the cable. Seemed like the coils were interfering with the communication square wave.
petteyg359
Well-Known Member
Assuming you have a 240v@32a EVSE, that's still less power than some induction stovetops require, and I'm pretty sure those induction stovetops don't have a half inch of insulation in the coils. I wouldn't hang my steel pan in front of the coiled charging cable, but only because that'd make it really hard to get to the cable and the edges of the pan would slice through it if I pulled on it 
Mr. Smith
New Member
Short Answer: No, it does not matter in terms of charging efficiency or safety. Coil away!
Long Answer (shortened for simplicity): All current carrying conductors create a magnetic field (EMF). However, since both L1 and L2 conductors are next to each other in the cable, and their currents flow in opposite directions, the EMF of one conductor "effectively"* cancels out the the EMF of the second conductor. [*Not "absolutely" because they are not perfectly collinear, but certainly "effectively" and beyond normal measurement capabilities.]
If you wanted to make a transformer, you would have to cut the outer cable sheath, split apart the L1 and L2 conductors, and coil them separately. You would then have an air core transformer (although a poor one). Wrap the now split apart conductors around and iron core and you have a "real" transformer.
Short of doing the above ridiculous shenanigan, you won't be able to detect or measure the "loss of power" of a coiled up intact normal power cable.
This is why when running industrial power cables (typically 3-phase), all three phases are run together in the same conduit, with the conduit grounded. Even if there are multiple cables per phase requiring multiple conduits (say 3 cables per each of phases A, B and C), then you run one cable of each phase in conduit 1, one cable of each phase in conduit 2 and one cable of each phase in conduit 3 (this is one example, there are of course variations).
Great answer! Thanks!