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Comment by Rebelgecko | Hacker News Reader

FWIW, this video changed my mind: https://youtu.be/zsNiupN1X7s

Part of what makes Tesla so successful is that they can make EVs cheaply. Using NACS instead of CCS seems to be one factor in keeping costs down:

because the charge door is smaller, they can make it part of the trim instead of having to match it to the body

The plumbing from the charge door to the battery also seems more cost effective

Watt for watt, dropping weight makes a small but real improvement in EV range

The latch setup also seems better, on Plugshare I see a decent # of chargers that are out of commissions because of how CCS puts the latch on the EVSE

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The difference between my car with a minutely smaller charging door is like maybe an ounce or two in weight. We're not even talking pounds. On a vehicle that weighs a few thousand pounds and will vary several hundred based on how many passengers are in it.

Shaving a few ounces isn't going to make a difference in range. With EVs, even adding a hundred pounds or two isn't changing the range that much. You get a ton of it back in regen so the vast majority of energy usage is rolling resistance (which a few pounds isn't changing) and aero drag (no weight difference at all).

I don’t necessarily agree to the parent comment, but I believe the point is that it eliminates need to attach, remove, and keep the fuel door by use of a temporary fixture during painting.

All doors and bumpers on a car is attached to the body during the paint process, then the whole thing is painted, disassembled, and re-mated later to the same chassis, for better color matching.

The door itself and the plastic bit are a minor part of the weight savings, I think most of it would come from what's just on the other side of the connector: With NACS you can throw everything onto the 2 aluminum bus bars in the vid, whereas CCS has a whole octopus of copper (relatively heavy and expensive) cables coming out of it

It's two extra wires. Two extra wires going a few feet. Let's say those two wires are 2lb/foot (that's way heavier than actual, but let's be generous here) and they need to go 6 feet (also, probably doesn't really go six feet, let's be generous).

That's maybe 12lbs of extra stuff. On a 4,500lb car. 12/4500. 0.2% difference in mass in a car with regen braking. You think that's enough for a difference in range?

I routinely get groceries weighing more than that. There's no effective difference in my range. I don't even have a noticeable hit in range with just a solo driver or four total people with bags, a difference of probably 600lbs or so.

The Lightning range estimates don't really change much with several hundred pounds of stuff in the bed. You really only start seeing range hits towing, and that's mostly because you're adding a lot of drag and extra rolling resistance with more tires.

I don't think the charge port is making that much of an impact on the range. Motor design and placement, aero drag, suspension, tires, battery size, inverter efficiency. These things will affect range, but not 12 extra pounds.

To have specific numbers, the wires for AC charging would be 2-8 gauge depending on max speed.

So the three wires would weigh 1-3 pounds total for six feet of cable.

IMO both latches are poor designs.

The NACS latch is entirely driven by the car, which is fine for the owner of the car — assuming the car is working as it ought to, the owner can disconnect a charger. But there is no intelligent logic for when someone (owner or otherwise) ought to be able to disconnect the charger without the owner’s help. In many cases, it would make sense to be able to disconnect someone else’s car once it’s fully charged, and disconnecting or connecting a charger in the owner’s garage should not require unlocking the car.

The J1772 latch is substantially more complex, and I’ve seen it get stuck. This is quite nasty when it happens.

> it would make sense to be able to disconnect someone else’s car

This seems like a bad idea for something designed by for use in public with no direct supervision. I would absolutely prefer that no one disconnect my car over having the ability to disconnect someone else's car. I can understand having some override that requires a little mechanical effort in the case of malfunction, repossession, or something like that. However, I wouldn't want any random person to be able to disconnect my car at their discretion. That is a recipe for chaos at charging stations. Plus the caveat of "once its fully charged", already means you need to let the car have at least partial control over the unlocking mechanism anyway.

There's already a two-way data flow in the standards, so the charger could just ask the car to unlock if someone requests that at the charger. It does make sense for it to be a request to the car and the car can know the driver's preference on desired charge level (should be at least 80% charged, for instance) and/or alert the driver somehow that the request has been made.

Does Tesla not have an option to unlock the plug when charging is done?

Wait what - people should be able to unplug other peoples cars? Why? The car will still be parked in the charging spot

I've seen plenty of places where there are two charging spots per charging cable. In which case it makes sense to unplug a car that's in the spot and full.

It sounds like it makes sense until someone else wants to charge their car regardless of whether yours is charged or not. That will be 99% of the use case for this. Just charge idling fees, that's a great deterrent for sitting there with your car fully charged and still plugged in. I'm not sure about all of the major networks, but Tesla and EA both charge those fees.

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