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Heat Damaged Charger Plug

Posted: Wed Jun 12, 2019 3:18 am
by Icarus
Hi all. First post here and keen for some iMiev advice.

I'm from Perth, Australia and test-drove a 2012 iMiev for sale at a local car dealership today. ... 4455/?Cr=0

I've previously spent a few hours reading through the contents of a few posts here to better understand some of the iMiev issues I might be faced with.

The iMiev for sale has very low kilometres for its age (7200kms - 2012). That did have me very curious but was unanswered by the salesman.

More concerning is heat damage on the 15 Amp Level 2 car charger plug. My limited understanding is that the OBC can have a failure mode that causes high inrush current (Pre-charger circuit failure?). I read a couple of UWA chargers were damaged by a particular iMiev, but the same car would charge on higher capacity chargers.

I'm looking at the attached picture and presume that the charger has pulled much higher current than designed. One of the pins on the plug is so loose it seems it could fall off.

The vehicle has a 10 Amp plug and Level 1 charger (undamaged) and also a 15 Amp plug and Level 2 charger (pictured). I wasn't in a position to check the functionality of either.

Any feedback on what could cause this? I've read through the 38 pages of 'Troubleshooting and repair for On-board Charger, DC-DC Converter', so I think I'm across most of those components.


Re: Heat Damaged Charger Plug

Posted: Wed Jun 12, 2019 7:28 am
by Don
Welcome to the forum! Sounds like you've found a very nice low miles (kms) car - Those are the best ones

The 'charger' is built into the car. What you're calling a charger is actually the EVSE (Electric Vehicle Supply Equipment) and a heat damaged plug on the EVSE has nothing to do with the condition of the charger in the car. The EVSE is nothing more than a 'smart' extension cord, used to connect the charger in the car to the AC mains in the house

Most times you see a melted plug on an EVSE it's due to an older, worn out socket in the house which causes a high resistance connection when you plug it in. EV's draw substantial current and for several hours, so even a slightly dirty connection at the wall can eventually result in an overheated connection - I'll bet the socket in the original owners house doesn't look much better than the plug in your photo. The EVSE regulates the amount of current sent to the car, so it wasn't caused by too much current for the charger, but obviously it was too much current for too long for the connection at the wall. You should be able to put a new plug on your EVSE and then make sure you use a new socket at your house to plug it into and you should not have that problem again


Re: Heat Damaged Charger Plug

Posted: Wed Jun 12, 2019 4:21 pm
by Icarus
Hi Don. Thanks for the quick reply!

Yes, my use of terminology for this new (for me) market needs improving. :oops:

My next step is to take it to a dedicated EV mechanic for an appraisal of the battery cells and functionality of both EVSE. I'd like to ensure that with the long storage time this vehicle must have experienced, there hasn't been any issues develop.

Any other useful tips when looking over a potential new (2nd-hand) iMiev?

Re: Heat Damaged Charger Plug

Posted: Thu Jun 13, 2019 5:26 am
by kiev
Howdy Icarus,

i assume that the dealer would let you test drive the car. When you turn on the key the dashboard will come alive and you can read the gauges. So check the "fuel" gauge to see how full it is and count how many bars are showing, Full is 16 bars. Half is 8 bars.

You probably won't know when or how it was last driven, or charged, or calibration charged, but at least you can look at the odometer data with the push-button display. Cycle thru the readings until you get to "RR" which is the range remaining. Note the value and do some quick math, a typical normal RR reading will be about 4 miles or 6.5 km per fuel bar. This is a quick and simple check on the overall health of the pack and the car in general, if you are close to this then the car is worthy, if not then questionable.

p.s. i agree totally with Don's post and think it would be an easy repair to the plug, maybe you can use that "damage" to get the price down a bit.

Re: Heat Damaged Charger Plug

Posted: Fri Jun 14, 2019 2:51 pm
by phb10186
Hi and welcome to the forum.

As others have said... nothing to do with the car's on board charger or the EVSE charging lead (which would protect the car from any damage anyway).

I've had this happen on my own 2012 IMIEV in the UK, also running on 230-240V domestic. As has been said, if you draw too much current from a power outlet in the wall for extended periods, and 3Kw for several hours is a lot for typical domestic wiring (especially if it's on a spur, rather than a ring main - hopefully the language complies here), then that can quite easily happen.

It happened to me when I had no option but to charge from fairly long extension lead, and it melted the Mitsubishi supplied 3 pin British plug to the RCD protector, which tripped the circuit - but funnily enough, neither the RCD on the plug, nor the fuse in the plug went - it was the main breaker in the electrical box in the house. It was a hot day by UK standards (about 32 degrees last year).

The fix was just to remove the melted plug and replace it, and it's all working fine now (though I replaced it with a hard plastic one, rather than the soppy soft-touch rubber-type Mitsubishi had supplied - so get a good quality one).

I don't tend to use the Mitsubishi supplied charging cable, but rather my Level 2 wall charger and Type2-Type 1 lead,. Even though the charging rate is 3.3-3.6Kw vs 3 from the standard kit, the wall charger is wired directly to my home fuse box via a short cable with a 6 or 8mm cross sectional diameter, rather than 2.5mm from standard wall outlets - so it's far safer, and offers far lower resistance - better all round... never had any issues.

If you were really unlucky with a wall outlet melt, then I could envisage it damaging the wiring in the wall, which could be a significant pain, and potentially highly costly to fix... which is another reason I try not to charge off a standard domestic plug, especially if I need a full charge, and any length of extension lead.

Looks like you have found a nice low-mileage car, which should be fine, but do get the battery health checked out, as very hot weather and prolonged full charge state isn't good for the battery... and change the 12v battery as a precaution, unless you can verify it has been changed fairly recently.



Re: Heat Damaged Charger Plug

Posted: Sun Jun 16, 2019 11:39 am
by kiev
i recently had the MCU fuse and OBC snubber caps fail in my 2012, and have made repairs with pictures in the troubleshooting thread.

But in thinking back to the events before that occurred, i had been using the OEM Level 1 EVSE to chargge my car for about 2 weeks. Usually i use my Level II Blinnk unit, but i had another car parked in the way and was too lazy to shuffle cars around. When i finally did make access, my OBC failed after 20 minutes or so after plugging in the handle.

After seeing this thread and the heat damage to the plug i looked at the extension cord end that i was using for my little period of Level I, and found that it has thermal discoloration and the Neutral slot has expanded open and is quite loose--almost no pressure is felt on insertion.

Now i'm thinking that an interruption of the AC mains may have occurred during this period, and it may have introduced damage to the snubber-and-fuse section of the OBC.

Maybe it doesn't always fail immediately the first time, but over several instances it can weaken or degrade the components leading to the catastrophic burp. Got to pay attention to the little details and not get slack in keeping stuff up to spec...


Re: Heat Damaged Charger Plug

Posted: Sun Jun 16, 2019 1:05 pm
by Don
One of the blessings of the EVSE Upgrade many of us did long ago is they replaced the standard L5-15 plug which came on the North American factory Panasonic EVSE's with an L6-20P twistlock (later they used an L6-30) which is a much more suitable plug for a higher current device - I think the primary reason they did this was because their modification made it a 120/240 device and they wanted to make sure we were using a plug rated for both voltages. If you wanted to plug it into a standard household outlet again, you needed to purchase a short pigtail to convert it back to an L5-15. Rather than doing that, I just replaced all the outlets in my garage which I intended to use for charging (both 120 and 240 volt) to twistlock receptacles on day one. I have 4 sockets and 4 EVSE's, all of them using that same plug & socket I even made up a 12 gauge, 25 foot extension cord with twistlocks on both ends. In 7 years of charging now 2 iMiEV's and our Volt, I've never had a single problem with any plug or socket . . . . all because the guys at EVSE Upgrade chose a better plug to put on their modified EVSE's

Whatever country you live in, there are *probably* better choices for your EVSE's than the household plugs that came on them and spending a little money upfront *might* save you from electrical problems later on down the line


Re: Heat Damaged Charger Plug

Posted: Sun Jun 16, 2019 6:33 pm
by Icarus
Hi kiev. That's interesting information and matches some of the observations I've read in other threads. Namely, that there sometimes appears to be a 'relatedness' between the failure of the MCU fuse/OBC snubber caps and EVSE damage. That's what pinged my initial concern.

Suffice to say I'm going into the purchase with 'open eyes' to the potential for an OBC repair. The information in this forum has made me comfortable I can carry out the repair myself if needed (instead of requiring a $4000 OBC replacement).

One further item I seek clarification on -

My intent is to integrate vehicle charging with the home automation system to switch excess solar production into the car. I can easily switch the house AC-side via contactors, but have read that this can also spike the OBC and cause damage.

My intent is to hack into the iMiev 'remote' and wire onto the buttons for relay control of the device. Unfortunately, the iMiev 'remote' has been lost and isn't with the vehicle.

Besides buying a new remote (are they still available/price?), what other mechanisms exist to remotely turn charging on and off?

Re: Heat Damaged Charger Plug

Posted: Mon Jun 17, 2019 7:18 am
by Don
All North America iMiEV's came with a remote control (of sorts) from the factory - It's my understanding that most other countries version of the car didn't. I know the ones sold in Europe didn't, but not as sure about the Aussie version. Are you sure the car you're looking at is remote capable? Anything in the documentation hint that it originally came with one? If it didn't, you can't add one now

The NA remote is ridiculously priced new from Mitsu (around US $1K) but others here have bought used ones for a couple hundred or so. There are even instructions here for programming it to work with your car (assuming your car originally came with one) so you don't have to pay a dealer $150 or so to program it for you

That said, so far as it being useful for turning charging on and off . . . . it's a bit complicated, but it might do what you're wanting

However, dozens of us here have used various timers to turn the power off and on to the EVSE so as to charge at off peak times and I don't think we've ever linked that sort of activity to OBC failures. The failure kiev was alluding to was from a dirty, overheated connection which can cause input voltage to vary all over the place and rapidly come and go as the dirty connection heats up and cools down - THAT could well be a cause for concern with the OBC health. Turing off charging with a mechanical relay from one source and then turning it back on from another source should be doable I think . . . . but I would definitely take kiev's advice on the subject - For sure he's the top of the knowledge base here for what may be causing failures


Re: Heat Damaged Charger Plug

Posted: Mon Jun 17, 2019 7:50 am
by Icarus
Thanks Don. That was a complete assumption on my part regarding the availability of remotes on Australian cars. I'm likely looking for something that doesn't exist.

After watching a video of the remote fob in action, I can see it would be a real challenge/disaster to re-engineer with hacked relay control and no feedback. A simple contactor on the AC supply sounds like the way ahead.