Honda Fit EV Overheats When Used with Blink Chargers

By · January 28, 2013

Honda Fit EV and Blink Charger

Honda Fit EV charging from Blink equipment that used to work fine, but now apparently overheats.

Like many EV drivers, I charge my Honda Fit EV almost exclusively on Ecotality’s Blink charging stations. Well, I used to. Ecotality installed seven Blink charging units at my place of work and when I first got my Honda Fit EV, I charged on them without any problems. However, over the course of a few months, some of them no longer charge my car.

After about 20 minutes of charging, the car stops charging. Honda sent engineers to look, and determined that the charge connectors were overheating and the Fit EV was stopping the charge before damage occurred. Over just a few months, more of the Blinks started having this issue.

Now, six out of seven Blinks overheat in just 20 minutes. For this reason, I now charge at Level 1 (120V, 12A) using the cord set provided by Honda. In this way, a full charge takes about 15 hours, but that's sufficient for me. I’m generally at work for about nine hours, and I rarely arrive empty.

But the issue is inconvenient, to say the least, because when I plug into Blink equipment, I never know if it’s going to overheat or not—unless I wait for about 20 minutes. Then, I have to continually check the charging status from my iPhone.

Most other EV manufacturers do not use thermal monitoring. The Nissan LEAF, Chevy Volt, Mitsubishi i-MiEV, and Toyota Prius Plug-in Hybrid have been okay, because they don’t pull more than 16A. The cars I’m worried about are EVs that charge at 30A, but don’t monitor temperature like the Ford Focus Electric and Toyota RAV4 EV.

Melted J1772 Inlet on RAV4EV

Melted J1772 Inlet on RAV4EV, photo courtesy of MyNissanLeaf user TonyWilliams.

So far, I've only seen one RAV4 EV driver who reported an issue with this, but the issue is a pretty serious one. The owner’s charge port and J1772 connector melted. The issue seems to have stemmed from an improper crimping job on the pins in the REMA brand J1772 connector. This is consistent with what I have been experiencing, as an improper crimp like this will get worse over time.

What worries me is that while my car stops after overheating on these faulty stations, I have seen other cars charging at 30A for several hours on the same stations. I have felt the connectors when the other cars are charging and they are warm—the non-faulty ones do not get warm at all—which means these cars are charging with very hot charge ports. While it’s not currently enough heat to melt the connector, it is putting extreme wear on the bad crimp, meaning the connector will get hotter and hotter each time. I always leave a note on these cars, warning them of the potential issues.

Melted J1772 Inlet on RAV4EV

Thermal Image of ITT inlet after using Blink REMA connector, courtesy of Ingineer. I have measured similar temperatures (131°F) on faulty connectors. I’ve measured good connectors at around 95°F after charging at 30A.

What To Do

Joshua Katz, Ecotality’s chief marketing officer, in an interview with PluginCars.com, characterized the problem as a communications issue in which the car and the charging equipment “are not talking to each other in the right way.” He said, “the Blink station may trip the temperature sensor and stop the charging.” Katz said that Ecotality is working with Honda to find a solution as soon as possible. “There are no safety concerns whatsoever, for the car or the driver.”

However, there is solid evidence that the problem relates to high temperatures, not miscommunication. Honda engineers monitored the temperature of the charge port and once it hit a certain point, the car shut off charging. I have also measured the temperature of the port myself with an IR thermometer on both good and bad charging stations and have seen a huge temperature difference.

Meanwhile, Honda created a software update that reduces the charge current
when the port begins to heat up. I am now able to charge on Blink
stations without overheating. Unfortunately, this is Honda providing a fix for
Ecotality's faulty hardware.

So, if you are an EV owner, what should you do? Here are some suggestions for some common situations:

  • If you drive a 2010-2012 LEAF, Volt, or other vehicle that charges at less than 16A: You are probably okay, but if you are technically inclined and own your vehicle, you can add temperature cutoff to your vehicle as described here.
  • If you drive a Tesla vehicle: To avoid melting your adapter, dial your charge current down from 30A when using a Blink (or any other EVSE with a REMA connector). We know that 16A is pretty safe and 30A isn’t, so be careful when going above 16A.
  • If you drive a Toyota RAV4 EV, Ford Focus EV, BMW ActiveE, or other vehicle that can charge at over 30A, but does not monitor the temperature of the J1772 inlet: Avoid Blink EVSE (or any other EVSE with a REMA connector) unless absolutely necessary to charge. While charging, feel the plastic shell of the connector, it should not get warm. If you are technically inclined and own your vehicle, you may want to add temperature cutoff to your vehicle or build/buy a J1772 extension cord, so the cord will melt and not your car.
  • If you drive a Honda Fit EV or other vehicle that monitors the J1772 port’s temperature: Whenever a Blink station overheats, report the issue to Ecotality via the Blink’s touchscreen. Avoid this charging station in the future.

New to EVs? Start here

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