Testing Tesla Model S CHAdeMO Adapter w/ Odd Over-Voltage Discovery – Video


Kman's Tesla Model S CHAdeMO charging adapter.

Kman’s Tesla Model S CHAdeMO charging adapter.

KmanAuto tests out the recently released CHAdeMO adapter for Level III charging of the Tesla Model S at CHAdeMO charging stations. He states:

“Testing the Tesla to CHAdeMO adapter for the first time. IT WORKS CAPTAIN! However, the station itself wouldn’t output it’s max capacity of 20kW (Sad I know, only 20kW DC “FAST” Charger). I only got 12kW. Either way, It works, and it’s a start. I will be testing a more powerful station, and including Thermal Camera footage as well showing any heat build up etc

We are happy to see that it works. However, Kman discovered something unexpected at a CHAdeMO station… Take a look for yourself in the video below:

Kman discusses the issue like this:

“Finally got a chance to test a HIGHER power CHAdeMO station tonight…. And…. It scared me…..
When the station kicked in, Voltages being pumped to my car were in excess of 460v. That is WAY THE HECK TOO HIGH! Can you say “HOLY COOKED BATTERIES BATMAN!!!”.

Thats right, lithium doesn’t like having too high of voltage being pumped into it. Even a Supercharger doesn’t go that high of voltage. In comparison, a FULLY CHARGED 60kW Model S pack tops out at 353v FULLY CHARGED. a 85kW Model S pack tops out at 404-405v Fully Charged!!!!

So, with my 60kW pack, the CHAdeMO station tried pumping in over 100v HIGHER then my pack would be fully charged. That, let alone my pack was NOT full, and at a lower voltage (about 340v, and if my pack was near empty, about 290v, Car is shutting down voltage is around 260v)

This is scary. And part of the reason why Tesla took so long to release this adapter. The direct access to the pack via DC is not something to be taken lightly. Now, my pack did survive this onslaught of high voltage, why? Because safety measures kicked in. As soon as the car sensed this high voltage, the contactors opened, cutting off the main pack, then, once voltage dropped back down (Most likely the CHAdeMO Tesla Adapter’s computer) told the station to BACK THE FRACK OFF! and it did. Once voltages dropped, contactors closed again, and charging commenced.”

Supposedly, this over-voltage jump is some sort of insulation test.  Is it damaging to the battery pack or other electric components?  We sure hope not. Perhaps this issue will be dealt with by Tesla soon?

Below Kman was attempting to do a speed comparison of a CHAdeMO station to a Tesla Supercharger.  The test didn’t work out as expected:

So, there appears to be a couple of faults with the CHAdeMO adapter and/or some compatibilities issue with the charging station and the Tesla Model S.

Categories: Charging, Tesla

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7 Comments on "Testing Tesla Model S CHAdeMO Adapter w/ Odd Over-Voltage Discovery – Video"

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It would be awesome if folks “testing” the CHAdeMO adaptor understood the actual process. There are three fundamental connections from a CHAdeMO station to the car (or adaptor, in this case). 1) High Voltage – two conductor, Positive and Negative. It does not use a ground, because unlike SAE-CCS Combo1 and its close cousin Tesla Supercharger, CHAdeMO uses an isolated system. This is IMPORTANT to know based on the comments in the article. 2) Low voltage communication – there are a total of 5 conductors used for establishing “proximity” and 12 volt electrical power for the vehicle’s onboard High Voltage relays. 3) CAN bus – two conductors for High and Low CAN signals, used to communicate the amperage between the vehicle and the charger After the car is plugged in to CHAdeMO and the and the analog handshakes are completed, the CAN bus is used to inform the car how many amps the charger is capable of providing, and the car requests only that many amps, or less. Now, begins what the “tester” person thought was going to “fry the batteries”, the High Voltage ISOLATION TEST. That means that the charger ramps up from zero to at LEAST the rated… Read more »

Interesting. Indeed I’ve seen the ‘insulation test’ hit 505v on our Kia Soul EV and likewise I’m certain the pack cannot take that voltage as an input.

I totally understand your frustration and am glad you posted. I’m sure you can see why this would be scary for a Model S owner though. 😉

And now you know why there’s no isolation test on a non-isolated charge system (SAE-CCS-Combo1 and Tesla Supercharger).

Thank you, Tony, for your comprehensive explanation of this. It is truly appreciated.

The reasons you require an adaptor for your Tesla car:

1) The plug / inlets are physically incompatible (obviously)

2) The grounding of High Voltage is incompatible (isolated versus non-isolated)

3) The communication methods are completely and grossly incompatible. Tesla uses unique digital communication sent over the High Voltage conductors. CHAdeMO uses safe and simple low voltage dedicated CAN communication that every western car has used for 30 years, INCLUDING TESLA !!!

Wow, ABB should have been ready for this. I think some are rack based, perhaps more amps could be added.

It sounds like ABB isn’t doing very well. Does anyone know? I’m sure there are far better CHAdeMO units out there, which are the best value?

Has anyone done a teardown of the Unit? I’ve heard there’s hardware and software that should get firmware upgrades inside.