Can't get full 80Amps out of Tesla Gen 2... How to monitor the J1772 negotiation??

[galstaf]

I don't know if the ForScan objects it describes actually exist. Most of them don't in prior sessions. Gemini makes up a LOT of sht.
But that is probably the only way to diagnose if an 80A offer request is actually being made and if the truck/EVSE sees it.

Flashing red lights can only tell me there is an negotiation error. I already know that.

I have another adapter coming tomorrow... will try that too.

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[ZSC100]

I don't know if the ForScan objects it describes actually exist. Most of them don't in prior sessions. Gemini makes up a LOT of sht.
But that is probably the only way to diagnose if an 80A offer request is actually being made and if the truck/EVSE sees it.

Flashing red lights can only tell me there is an negotiation error. I already know that.

I have another adapter coming tomorrow... will try that too.

You can tell exactly what FORScan extended PIDs exist by filtering by module. The ones you are after for diagnosing this are part of the SOBDMA, And are pilot voltage and pwm duty.

 

[ZSC100]

I don't know if the ForScan objects it describes actually exist. Most of them don't in prior sessions. Gemini makes up a LOT of sht.
But that is probably the only way to diagnose if an 80A offer request is actually being made and if the truck/EVSE sees it.

Flashing red lights can only tell me there is an negotiation error. I already know that.

I have another adapter coming tomorrow... will try that too.

AI doesn't know jack shit about a ripped off diagnostic software from Russia other than what It can read from the FORScan forum or others posts.

 

[galstaf]

AI doesn't know jack shit about a ripped off diagnostic software from Russia other than what It can read from the FORScan forum or others posts.

Lol.. Well aware! Most of it's suggestions don't exist.

It is a pretty convincing liar tho!

 

[garsh]

Lol.. Well aware! Most of it's suggestions don't exist.

It is a pretty convincing liar tho!

Yep, I always try to check the "supporting material" links Gemini provides. I'm always a little shocked when I find nothing that supports the statement being made by Gemini. But I'm glad it provides those links so I can double-check its conclusions.

 

[tls]

The Gen1 wall connector puts out a dirty pilot waveform that Ford and some other vehicles won't accept at 80A. This has been discussed here several times. There is no solution.

The Gen1 wall connectors are also very old now and lack features like the ability for multiple units to share a circuit. The eBay seller basically ripped you off, is my take.

A forum search is likely a better first step in this kind of thing than feeding AI slop to an AI to see what it vomits up next.

 

[ZSC100]

The Gen1 wall connector puts out a dirty pilot waveform that Ford and some other vehicles won't accept at 80A. This has been discussed here several times. There is no solution.

The Gen1 wall connectors are also very old now and lack features like the ability for multiple units to share a circuit. The eBay seller basically ripped you off, is my take.

A forum search is likely a better first step in this kind of thing than feeding AI slop to an AI to see what it vomits up next.

Hearing this, grab you an an Oscope and check out the signal. It might be as simple as adding a resistor or capacitor to the CP.

 

[tls]

Summarizing long ago discussions about this, at 80A - 100% duty cycle - the Lightning won't accept the Gen1 unit's signal. At lower settings, there's a possibility of a mix up with the DIP switch settings because there were two hardware revisions and the settings for some of the current limits were swapped. If your unit is working at 64A, this might confirm one of the long ago theories, but nobody has ever been able to make one work at 80A. If you read the below you might see a test you could run to find out whether 72A is achievable on your particular unit. But be aware due to the DIP switch mixup 72A can appear to work but actually be limited to 24A!

https://www.f150lightningforum.com/...-j-1772-adapter-not-working.11822/post-338010

Also worth noting even Tesla's newer (than 2012!) in car charger designs had trouble with the Gen1 HPWC. There was a brief period before Tesla reduced all their car's onboard chargers to 48A, when they were selling Model S and Model X cars with dual 48A chargers for 72A total current, and these cars would not reliably charge at Gen1 HPWCs, resulting in Tesla actually replacing many of these EVSE with Gen2 for free when the owners complained. They may have been state of the art at the time but these days a Gen1 HPWC is really just bad news, sorry to say.

 

[chriserx]

Anyone else get a kick out of how 'long ago' isn't even 3 years. One more case study proving time dilation.

 

[Oafy44]

If you want to use the full 80amp charger you need a 100a breaker

 

[chl]

On the bright side, 64A will put a bit less stress on the battery and give the DC-DC converter more time to charge the 12v battery.

 

[garsh]

On the bright side, 64A will put a bit less stress on the battery and give the DC-DC converter more time to charge the 12v battery.

Batteries don't see "stress" from high AC charging rates. 64 amps at 240 volts is only 15kW. You need to get to 1C-2C rates before charging stress starts to happen. For a standard-range Lightning, that's 100kW-200kW.

Charging at the fastest AC rate you have available gives the best charging efficiency.

 

[chl]

Batteries don't see "stress" from high AC charging rates. 64 amps at 240 volts is only 15kW. You need to get to 1C-2C rates before charging stress starts to happen. For a standard-range Lightning, that's 100kW-200kW.

Charging at the fastest AC rate you have available gives the best charging efficiency.

Stress, it's all relative...

Lower current inherently creates less heat, that is just physics, even if it is just a "bit less" (the words I used)...the difference should be negligible of course if the BMS is managing the temperature well.

I was being a little bit facetious about it, looking for a silver lining to the cloud.

Not sure about "charging efficiency" being better at higher currents though...you'd have to define what you mean.

Higher current will require more thermal management by the truck, and the I^R heat loss in your wiring (service panel to EVSE to Truck Port, etc.) would be higher as well - that's why utilities use high voltage for transmission after all, to reduce the current for the same power and minimize I^2R losses.

Yes, DC charging creates the a lot of stress, no argument there!

 

[galstaf]

f you read the below you might see a test you could run to find out whether 72A is achie

There is no setting on my version for 72A. That is the later model with the rotary dial to set amperage. Mine is the 4 linear DIP switches and the next lowest after 80A is 64A (which does work fine).
It is definitely about that amperage also.. About twice as fast as the Ford portable 32A EVSE.

I did search for relevant threads .. there was a lot of noise. Didn't find this one you are referencing for sure.
What did you mean by "dirty" waveform? Has someone looked at it with an oscilloscope?
Has anyone tried Zach's idea of putting in a resistor? As the pilot uses pull down resistors to change the voltage for signalling, would that not mess things up or could it trick the unit into functioning?

Sorry again for the newbie questions. It is hard to find answers on some of these threads.

 

[galstaf]

Hearing this, grab you an an Oscope and check out the signal. It might be as simple as adding a resistor or capacitor to the CP.

Wouldn't the resistor mess up the voltage pull down?


Would the capacitor help? Are you suggesting it to smooth the waveform?
I am weak with building circuits, so would love an explanation from an EE if you could.

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