Cybertruck L2 Charging -> Tesla Gen 4 80amp Wall Connector

CyberGus

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FYI, Level 2 charging is converted to DC by the vehicle's on-board BMS. If the internal circuitry only supports 60A charging from AC, then it won't matter if your EVSE ("Tesla Wall Adapter") can supply more.

I believe that's the real reason Tesla dropped AC charging to 60A: it made every car cheaper to produce.
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kpanda17

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If you have any chance of buying a CT or any other large EV and in the market for EVSE aka Tesla Wall Connector, future proof your home charging. Be ready for 100amp circuit and 80 amp charging.
back to the future
 

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If the original WC works to deliver 80a to the CT I'll probably have to re-wire it as I only put in big enough wire to power 60a/48a delivered. Or perhaps I can do like Tesla and monitor cable temps and derate if they get warm.
My mobile charger does that. Had to drop to 29a or it will force itself to 16a.

Time for a real charger when CT comes
 

HaulingAss

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My mobile charger does that. Had to drop to 29a or it will force itself to 16a.

Time for a real charger when CT comes
Have you determined why it forces itself to 16 amps?

I think it can only be due to either:

1) excessive voltage drop in the circuit which implies your wiring might be undersized or have electrical connections that are oxidized and/or under-torqued. It could be at the wiring to the breaker, to the back of the wall outlet (including the where the prongs plug in) or an intermediate junction box.

2) Heat gain at one of the three plug-in connections, the wall outlet, the car's charge port (unlikely) or the body of the Mobile Connector.

It's worth determining what it is before it gets worse. I'm guessing it's either voltage drop or heat detected at the wall outlet.
 

HaulingAss

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Does this mean you have 2 meters and service fees?
Yes, but the meter fee for the carport service is only $8.85/month and the electricity it delivers is not tiered. The base rate per kWh (about $0.09/kWh) is cheaper than 100-amp service to our house so it all works out. More so when we add the Cybertruck to the two Model 3's we regularly charge there.

One of our Model 3's has free Supercharging for life but our electricity at home is so cheap it's not worth it to fill up at a Supercharger, unless I'm on a road trip.
 


Gurule92

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Have you determined why it forces itself to 16 amps?

I think it can only be due to either:

1) excessive voltage drop in the circuit which implies your wiring might be undersized or have electrical connections that are oxidized and/or under-torqued. It could be at the wiring to the breaker, to the back of the wall outlet (including the where the prongs plug in) or an intermediate junction box.

2) Heat gain at one of the three plug-in connections, the wall outlet, the car's charge port (unlikely) or the body of the Mobile Connector.

It's worth determining what it is before it gets worse. I'm guessing it's either voltage drop or heat detected at the wall outlet.
Its heat at the plug (wall) nema 14-50.
 

HaulingAss

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Its heat at the plug (wall) nema 14-50.
That's what I thought and the reason why I think hardwiring is far superior to spending the money on the NEMA 14-50. Of course some people have existing NEMA 14-50's but I still recommend hardwiring.

I wouldn't wait for taking delivery of the Cybertruck to address the problem because the daily heat cycling of the outlet caused by the way you are using the plug could be causing the screw terminals to be gradually loosening. It's probably as simple as flipping the breaker off, checking the outlet for stray voltage with a voltmeter, pulling the NEMA 14-50 and making better connections on the wire terminals. If that's not it, taking some contact cleaner to the blades of the plug and outlet contacts, followed by some fine emery cloth will probably eliminate your problem.

It could also be low spring pressure on the plug blades if the outlet is a cheap light-duty outlet (as most of them are). In that case, the only real solution, besides hard wiring a Wall Connector, is replacing the outlet with a quality outlet. Even if it's low spring pressure, cleaning the contact surfaces can make a world of difference in the short term, until they oxidize again.

The potential consequences are too serious to risk. The problem here is you are relying on the thermocoupler and software in the Mobile Connector which is only intended as as a safety backup, not a primary prevention device. It has no backup.
 
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kpanda17

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Ok, the CT is here
Who knows the max current for L2 charging?
Is it 80 amps?
 

Jhodgesatmb

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If the original WC works to deliver 80a to the CT I'll probably have to re-wire it as I only put in big enough wire to power 60a/48a delivered. Or perhaps I can do like Tesla and monitor cable temps and derate if they get warm.
House fire alert! Good luck with that one.
 

Jhodgesatmb

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My problem is that I cannot take advantage of the significant EVSE rebate from Austin Energy until I have a VIN. Can I charge a Cybertruck with 120V and a really long extension cord? We're gonna find out!
I’ve run water pumps overnight with 150’ of extension cords and they got pretty hot.
 
 




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