[TimWI]

Hi. New to this forum, and a recent owner of an electric Smart fortwo, which is a great driving experience. I have had the vehicle for about one month, though it is four years old. I am charging it at home using the provided 120 volt charger unit. The unit frequently faults, showing two flashing red lights. This doesn't happen all the time, but often enough to make overnight charging very hit or miss. Have tried swapping sockets etc, with some benefit, but no complete solution. I think it faults more often if I charge at the high setting, but not 100% on that. Vehicle was at dealership for annual service, and I had them check the charger unit. They said charger unit is fine, car is fine, but when pressed, said the cable might be at fault. I complained to them again, and they asked me to bring it back for more diagnostics, but haven't said why or what. Anyone with any ideas on this problem? What kinds of problems cause the unit to fault and stop like this? Do I need a new charger? Could it be something with the vehicle? Any help from those of you with lots of experince of these is most appreciated.

Finally, forgive a newbie if this is the wrong sub to post this, and I will relocate to the right one.

 

[jwight]

Welcome to SCoA!

 

[MB DNA]

Welcome to SCoA. While it could be the EVSE your home electric circuit sounds suspect - try another circuit not just another plug. Try plugging it in at a neighbors house?

Amp capacity, grounding and current load from other devices can all contribute.

 

[TimWI]

Thanks so much for the response. So you are suggesting it might be the home circuit rather than the charger itself. If it is, what can I do to test/fix this?

 

[InjuredAgain]

I don't believe I have ever seen an accurate list of things that will cause the supplied EVSE to complain. But somehow it is looking at the supply power and determining if it can charge at maximum current.

Possible things you could do would be to see if any other devices are also using power on that same circuit, and to check for the integrity of that circuit and the power wiring themselves. Worst case, you might have to run another circuit and create a dedicated outlet for charging, though if you do that you might as well make it a level 2 capable outlet.

 

[TimWI]

Thanks for the information. The garage/powder room circuit I am using has three receptacles, and also runs the lights. The only other major appliance on the circuit is the garage door opener. The circuit is 20 amp. So, when I run the charger, there is really nothing else drawing major load. The circuit breaker has not tripped. If it is the circuit, I would guess it is some kind of transient ground fault. The faults don't seem to correlate with any usage in the house, though I will say that I seem to have better luck charging at night.

I am pursuing MB DNA's suggestions, and will give report. It would be useful if Smart gave more information than they do about these issues. As you say, it would be handy to know what kinds of issues trigger the charger to fault. I have read the manual carefully, and find not much that helps there. Not for the hacker minded for sure!

Thanks again.

 

[InjuredAgain]

Sometimes household wiring is more jury-rigged than it seems to be. As a case in point, the circuit that powers our garage plugs, which I use to charge our ED with the factory EVSE, is also wired to just one of the two floor mounted plugs in our formal living room. I found that out when I plugged a vacuum cleaner into that outlet and blew the breaker when the car was charging.

Normally there is just a floor lamp plugged into that outlet, and this last winter we left that light on during the dark winter days. When I swapped the bulb for an LED, the car would take a couple of hours longer to complete its charge. Something about the LED bulb on that circuit caused the equipment to charge at less than full current.

I just went "huh" and started using the other lamp on the other outlet.

Good luck chasing down your issue.

 

[lebikerboy]

A friend who has a Leaf noticed that his car doesn't charge at full capacity when
all the computers, home theatre, washer/dryer, air conditioner, stove, microwave,
refrigerator, freezer, dishwasher etc.are running at the same time. He surmised
that this is caused by the 100 Amp panel during the current hot weather spell we're having...



When I installed the unswitched outlet for our smart car, I installed a home run
back to the panel so the charger gets the full 12 Amps it requires. Also, as we don't
have a plethora of teens at home, the total demand on our panel is fairly low.

 

[TimWI]

Thank you InjuredAgain and lebikerboy for more comments. I am familiar with the strange arcana of what is connected to what in house wiring, as your stories well illustrate. Also familiar with mice gnawing wiring, which had to be fixed when our bedroom lights started flashing.

I have just found that I misstated the max amperage of the circuit I am currently (pun not intended) using. It is 15 Amp and not 20 amp. Though there is nothing else on the circuit, might a circuit close to load trigger a fault? Am I right that the amperage for the supplied charger is 8 amp at low setting and 12 amp at high setting? I can't find this information presently in the manual.

The experiment so far: I switched to a second circuit, also rated 15 amp, and quickly got faulted several times at the high charge setting. I am presently charging it at the high setting on a 20 amp circuit dedicated to the washer (not running), and it has charged for 90 minutes so far without faulting. I will run it on this circuit longer to see if it continues without fault.

 

[InjuredAgain]

In the instrument panel charging menu, there are three settings of 8 amps, 12 amps, and max. When the remote access app was working, and if it could be believed, the max setting would result in charging at up to 1.8 kilowatts on 120 volt, with the EVSE set to four lights. I would tend to believe that as there were times when I could charge from 10% to full in less than 12 hours.

And again, when the web app was working, it would show a pattern of higher current charging followed by a slightly lower current, cycling over a period of about 15 to 20 minutes. Possibly it was doing that as a test to see if the AC power supply was adequate, or maybe that was best for battery health? I just don't know.

 

[TimWI]

Thank you again InjuredAgain for the information. I hadn't thought to look at the charge setting for the car. Just now checked it and it is set to the default of Max. If, as you say, the Maximum rate is 1.8 kW, then the current would be 15 Amp at 120 Volt. That would have been taking my garage circuit to maximum load, though, as I said, the breaker was not triggered. My charger unit seems only to toggle between two lights and four lights. Not sure if the two light setting is 8 or 12 amps. Any thoughts on that? I would guess it is 8, and that a 12 Amp charge rate would have to be set in the car with the charger unit toggled to Max. I don't understand why the charger unit would not give all three settings allowed.

Nothing more yet to report on charging. More on that tomorrow. Today was laundry day so charging was low priority!

 

[InjuredAgain]

It kind of feels like the EVSE and the car's charging menu were designed independently because they don't seem well integrated with each other. My experience has been that two lights on the EVSE means 8 amps maximum, and four lights means the maximum of what the car will accept.

I've thought about using our laundry dryer circuit as well, but I generate enough laundry to need to do it at least every other day if not more. . .

 

[jimsokoloff]

The EVSE and car handshake "negotiate" the current allowed to be drawn during charging.

More precisely, the EVSE advertises the current capability that the EVSE can deliver and the car is free to draw up to that amount of current. Assuming everything was implemented properly (and I have no reason to think otherwise), the car will charge at the lower of the rate the car is programmed to take or the rate the EVSE is set to allow.

The EVSE and the car almost surely *were* designed somewhat independently and that's OK/desirable in a standards-based world.

 

[TimWI]

Thanks InjuredAgain. So 8 Amps on low, and 12 or 15 Amps on high depending on the car menu setting. I'm only using the laundry circuit as a temporary hack to see what the problem is, as per the original suggestion. I will be very unpopular if I keep doing this! Next stop is my neighbor's front door to see how his circuit works. So far, the laundry circuit (20 Amp) has proved much more reliable, but not perfect. I have had the car charging at max for the evening, and it has faulted twice. I have gotten about 18% SOC in three hours of charging. I was unable to charge on max at all on the garage circuit (15 Amp).

Thanks Jimsokoloff for your comment. I assume that the charger is meant for more cars than this model. Not sure why they could not have given the same three settings (8, 12, 15) on the charger as the car takes. It would be simplest to leave the car at max and select the charge rate on the charger. The manual seems to imply that the charger can be different for different markets, and there are, potentially, four settings since there are four lights for the charge rate.

 

[TimWI]

OK, so I have completed trials over a few days with various outlets, and have to say that unless the power supply in our neighborhood is unstable and the cause of the problem, it must be something wrong with the charger unit. The washer circuit in our house was the one, on which the charger seemed at first to give the best charging, and I was able to charge at max for a few hours. Now, the charger is faulting very often on that circuit, usually after no more than 10-15 minutes of charging, and regardless of whether charging is at 8 amps or max. My neighbor's external outlet was much worse. One of the two receptacles faulted immediately, and did this on several attempts to us. The other started, but charging faulted after about 10 minutes.

This is a difficult problem to pin down. Does anyone have any further ideas?

 

[MB DNA]

Not sure where you are located but, any other EV owners (generally a helpful lot) in the neighborhood? If so, might try their OEM Level 1 EVSE vs. yours on the same circuit?

If you are still under warranty, this may require a trip to the closest smart Center? If further "testing" points to a faulty EVSE, might be less hassle to pick one up off eBay at $175 - 275?

 

[InjuredAgain]

I don't know if I've read if you've tried a commercial charger. If so, try to charge it fully on one of those. You can then mostly rule out that the problem is with the circuitry inside the vehicle, and can concentrate on the EVSE itself or on possible wiring issues in your home.

 

[Mister_smart_LA]

If your charger continually faults, most likely you need an electrician to update and upgrade the grounding at your house or charging circuit.


Try another house and see if that makes a difference.

 

[TimWI]

MB DNA: Thanks. Car is under a three month warranty from a used car outlet, so may need to contact them. I don't know any other EV owners, but will look. Not too many smartcars in our area, but a few more leafs. Dealership not too helpful. Serviced it and said all worked well, but then offered to do more unspecified diagnostic work for $100 per hour.

InjuredAgain: Thanks. Good idea, I will find one.

Mister_smart_LA: Thanks. I have already tried a neighbor's house and get the same result. Their house recently rebuilt, so recent wiring.

Ovewrall, I suspect the charger, but this sure is tough to pin down. I have contacted SmartUSA technical support to see if they are any more help than the dealership.

 

[Mister_smart_LA]

MB DNA: Thanks. Car is under a three month warranty from a used car outlet, so may need to contact them. I don't know any other EV owners, but will look. Not too many smartcars in our area, but a few more leafs. Dealership not too helpful. Serviced it and said all worked well, but then offered to do more unspecified diagnostic work for $100 per hour.

InjuredAgain: Thanks. Good idea, I will find one.

Mister_smart_LA: Thanks. I have already tried a neighbor's house and get the same result. Their house recently rebuilt, so recent wiring.

Ovewrall, I suspect the charger, but this sure is tough to pin down. I have contacted SmartUSA technical support to see if they are any more help than the dealership.

I'd try a public charger to see what results. Or try a different EVSE charger of the Level 1 variety. Any J1772 should work.