Bad quality OEM portable charger...???

Almost five years now, I am the owner of an i3 REX.
I nearly always charge at home and to do that, I'm using the portable charger as supplied with the car.
Of course the dealer tells me, I should use a wall charger unit, but I don't see any reason for that.
The lower charging speed of the portable charger is fine for me and never gave me any problem with the way I'm using the car.
And using the standard supplied portable charger, should even be better for the battery lifetime because of the lower charging current!!

Anyhow, in our "energy plus house" (even including 2 electric cars and a heatpump for heating our nett usage is zero over a year) I'm always looking for ways to save a few kWh's. For those of you interested, look here (it's in Dutch, but Google translate can help): https://geen-energierekening-meer.weebly.com/


And I noticed that the 230V cable of the OEM charger was a little warm during charging. I also noticed that this cable was actually quite small in diametre compared to the same 230 V cable from my wifes Volkswagen E-Up charger. So I compared the two chargers and the cable diametres.
I shot this picture. In the top of the picture you see both 230V cables and at the bottom the charging cables that will go from the charger to the car. The right charger is from the i3 and the left one is from the VW E-Up. Draw your own conclusions...


So by knowing the 230 V cable to the charger was quite small (in cross section area for the conductors as well of course, I measured 1,5 mm2), I thought I'd take an infrared picture of the cable (inside the outdoor-cabinet were the charger is located):


And as I expected, the cable was warm, but the connection from the cable to the plug was even warmer.
A closer inspection of the temperature of the plug showed a temperature of 54°C (129F):
image uploader

Well mostly this is a bad connection between plug and socket, but after a closer inspection it looked like it was not this connection, but the connection between the cable (with small cross section) and the plug pins.
The resistance I measured over the 230 V line was about 2*0.2=0.4 Ohm. This is a loss of 23 Watts (at 10.8 Amps of measured cherging current in the 230V line). The calculated loss over 2 x 1.7 metres of 1.5 mm2 cable is only 2*0.02=0.04 Ohm
Following photos shows what the plug was looking like:




Of course I replaced the 230 V cable and plug. This time with decent 2,5 mm2 cross section cable and a plug with 2,5 mm2 connections.
This is the result. Just to be sure, I also replaced the wall socket.

No more hotspots in plug or cable. Of course the cable is a little heated up from the side of the chargebox.

I did not like the portable charger at all, even at 110V it became quite warm to touch. I was little worried that portable charger might junk the car if something goes wrong.(Even today, i am not sure if my auto insurance will cover should that happen).

IMHO, the more common problem when using a plug-in EVSE is from a worn receptacle verses the unit itself. If it isn't somewhat hard to insert the plug, the contact may not be ideal, and things can overheat. To pass UL (in the USA) testing, things can't be overheating, but it assumes your receptacle is not worn out and the contact pressure and surface area are still like new.

FWIW, the conversion in the car from 120vac verses 240vac is less efficient. SO if you want to get the most from your charging, you'll use a 240vac input.

From what I've been reading lately, wireless, inductive charging can be more efficient than using a plug. That option will start to show up eventually. Getting the two coils aligned is the critical thing, though.

The 1 foot cable to the charger head of my 2017 model is better than the 2016 charger. I think 2016 is 14 AWG and 2017 is 12AWG. Everything else is same.
It made by delphy and looks a identical copy of clipper creek design.
Looks like he the difference is inferior quality....

As has been pointed out, most of the time plug overheating is caused by the receptacle, not the plug, with loose/worn contacts, or badly connected feeder wires, though not always. I have (had) a Clipper Creek 120 v charger I was using, where the plug would get very hot during charging. I changed out the old receptacle to a commercial grade one, with no change in the plug getting hot. Then tried an OEM i3 120v charger in the same receptacle, and the plug stayed normal temperature - so the Clipper Creek charger had a defective plug that was causing the overheating. Clipper Creek replaced the unit for free under their three year warrant - and impressed me with their fast/great customer service people.