Occasional use charger nearly started a garage fire

Smelled something burning in the garage and noticed the charger plug was very hot.

I have been charging the car in the garage 115V L1 (car set to max current) for 2 months now with no problems until tonight.

I noticed before that the cord would get only slightly warm.

The only difference is the car was almost completely discharged today while I usually charge from ~1/2 discharged.

Does the car pull higher current if completely discharged?

I set the car charging current to low and now the plug is cool.

Two things:
- you should always ensure that the cord is fully out and free and NOT partially wrapped around the EVSE prior to using it.
- if there is a loose connection in the plug (either the receptacle contacts or with the wire(s) going into it), it can generate a lot of heat when you have a long duration, high current use

Now that that receptacle has been overheated, you should replace it since if nothing else, it will have lost some spring tension. While you have it out, double check that the wires going into the clamps are tight.

IF your input voltage was low, that will try to compensate by increasing the current levels. Still shouldn't try to use more than 12A, but it's hard to say how well it is calibrated. The receptacle should be able to handle 12A continuously, but only if it is in perfect working order.

The cord is never wrapped.

Do you think the car pulls higher current when the batteries are nearly discharged?

My range was down to 4 miles.

Thanks

My guess is that, no, the car doesn't pull more power when the battery is lower BUT it will pull it longer. If the power to the receptacle's contacts is loose, it will act like a resistor, and things will get hot. Replace the receptacle, verify that the wires are attached properly and if there is a twisted connection (wire nut(s)) in there, make sure that those are all tight. THen, just to be sure, make sure you don't have aluminum wire in the walls. If you do, get an electrician to make an approved splice to patch in a copper pigtail. Can't tell the age of the building, but AL wire when used to save some money can be a real problem.

If you want to monitor the power, then pick up a plug-in monitor - something like a 'Kill A Watt' from P3 International. It will show you the volts/amps/Kw/Hz of the inlet power and how much power is passing through it. http://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU/ref=sr_1_1?ie=UTF8&qid=1430112106&sr=8-1&keywords=kill+a+watt

If the receptacle doesn't grab onto the plug tightly, that can cause the symptoms you're seeing.

That looks like a dodgy socket problem, not a charger problem to me.

Do the 110v chargers come with such a short charger to wall socket cord that it has to hang off the socket like that? My 240v charger has at least a 6 foot cable on it, and I can easily plug it in without stressing the wall socket connection.

I33t said:

That looks like a dodgy socket problem, not a charger problem to me.

Do the 110v chargers come with such a short charger to wall socket cord that it has to hang off the socket like that? My 240v charger has at least a 6 foot cable on it, and I can easily plug it in without stressing the wall socket connection.

Click to expand...

Agreed, that cable to the mains socket looks really short compared to mine. Hanging like that will but some pressure on the pins in the socket and could lead to a less than perfect connection = heat.

Do the US chargers have three pins on the plug or just two?
I know when I'm in the US the two pin plugs never seem very secure to me compared to the UK's three square pins?!

mrsmith said:

I33t said:

That looks like a dodgy socket problem, not a charger problem to me.

Do the 110v chargers come with such a short charger to wall socket cord that it has to hang off the socket like that? My 240v charger has at least a 6 foot cable on it, and I can easily plug it in without stressing the wall socket connection.

Click to expand...

Agreed, that cable to the mains socket looks really short compared to mine. Hanging like that will but some pressure on the pins in the socket and could lead to a less than perfect connection = heat.

Do the US chargers have three pins on the plug or just two?
I know when I'm in the US the two pin plugs never seem very secure to me compared to the UK's three square pins?!

Click to expand...

The supplied EVSE is a 3-pin (i.e., grounded) plug. Many receptacles are located closer to the floor, and in most cases, the case of the EVSE would then sit on the floor rather than hang. It's not uncommon for receptacles in a garage, though, to be higher on the wall. The overall length of the level 1 EVSE supplied is about 18 feet, end to end.

I33t said:

That looks like a dodgy socket problem, not a charger problem to me.

Do the 110v chargers come with such a short charger to wall socket cord that it has to hang off the socket like that? My 240v charger has at least a 6 foot cable on it, and I can easily plug it in without stressing the wall socket connection.

Click to expand...

It's not hanging and has a good radius service loop ... it's just the picture.

I moved the plug to a different crappy, aluminum wired outlet in the garage for further testing:

She's been charging on max for an hour so far and the plug seems normal temperature.

Shoulda brought my IR gun home from work to monitor the plug's temp increase

I'll let the pics speak for themselves ... whadya think?








Low power charging


Reduced Power charging


Max Power charging

The car is showing a 19 hour full charge time on max at the above 11.5 AAC

Is this normal?

If you have aluminum wiring, poor or oxidized connections are a known problem. It may behoove you to do some remedial upgrades. There are at least several 'fixes' that are known to work reliably.

For those that may not be aware, there was a period of time where copper wiring prices spiked radically, and for a time, aluminum wire was used as a less expensive substitute. AL is a great conductor, but it really likes to be more stable and oxidizes. That small interface can create a significant resistance, and create heat with current flow. Fires from old aluminum wiring that has not been 'fixed' are not uncommon, and has nothing to do with the device plugged in except as a symptom of E=IR and the resulting heat. An EV is probably one of the bigger loads you plug in, and it isn't surprising it showed its ugly head here.

So is it ok to set the charge to max? How much faster is the charge?
I have a older home with just 100 amps
Thanks
Barry

The car won't pull any more because your SOC was very low. I'd bet this a case of a bad outlet, or loose connection. You shouldn't have an issue pulling ~12amps, even for many continuous hours.

The battery pack has a usable range somewhere between approximately 18-19Kw. Given that it slows down as it reaches full capacity (not as much with a level 1 EVSE as with a full-power level 2 unit), and that making high voltage DC from 120vac verses 240vac isn't as efficient, yes, 19-hours is entirely normal from a nearly dead pack to full charge. Some of the power is used to run coolant, pumps, and fans and doesn't go into the battery, either. This is one reason why they recommend a level 2 unit if you're going to want max charge in a more reasonable time. Europe gets a small level 2 unit because their nominal power is 220-240vac, and they have a better chance at being able to get by with that alone verses say a 32A unit. I see less than 120vac as your input, too, which when current limited, keeps the recharge rate down a bit as well.

My nominal level 2 input is 247vac, and at 30A, can reach the max capacity of the i3's charging units, or close enough to not count! Power=volts*amps.

If your wiring is up to snuff, you should be able to use the OUC at full UNLESS it is a shared circuit. I have 100A service at my condo, and installed a dedicated 40A circuit for my EVSE...works fine. The OP has aluminum wiring, which, if updated with the proper crimps or anti-corrosion material, should also work. It requires a receptacle designed for AL or CU wiring, though, or the addition of copper pigtails to the AL wirings done properly to be safe. Unfixed AL wiring is dangerous. AL wiring corrodes creating what works just like a heating element in a toaster...it not only generates heat, but lowers the voltage to the load.

jadnashuanh said:

The battery pack has a usable range somewhere between approximately 18-19Kw. Given that it slows down as it reaches full capacity (not as much with a level 1 EVSE as with a full-power level 2 unit), and that making high voltage DC from 120vac verses 240vac isn't as efficient, yes, 19-hours is entirely normal from a nearly dead pack to full charge. Some of the power is used to run coolant, pumps, and fans and doesn't go into the battery, either. This is one reason why they recommend a level 2 unit if you're going to want max charge in a more reasonable time. Europe gets a small level 2 unit because their nominal power is 220-240vac, and they have a better chance at being able to get by with that alone verses say a 32A unit. I see less than 120vac as your input, too, which when current limited, keeps the recharge rate down a bit as well.

My nominal level 2 input is 247vac, and at 30A, can reach the max capacity of the i3's charging units, or close enough to not count! Power=volts*amps.

Click to expand...

Thanks for all your insight on this subject and the whole Forum.

So what are the charging time difference on different setting, low, medium and max?

barrychan said:

So what are the charging time difference on different setting, low, medium and max?

Click to expand...

Here it's 19 hours on max from fully discharged

Longer for reduced and low



This is the first time I have run the battery completely down and then charged at home L1 115V

I usually hit the dc fast or L2 around town and then top it off at home

The charging rate is somewhat linear - not quite, but close enough for a WAG. I do not remember the 'steps' on max, medium, low on the US level 1EVSE, but would probably not even bother running it on low unless there was just no other place to plug it in and that circuit needed to share its power with a common breaker. In the USA, a 'typical' 110vac receptacle is protected by a 15A circuit, but it needn't be dedicated to one purpose. The largest 110vac receptacle commonly found is a 20A one, but not as often in residential situations. To get more power, you need to generally go up to a 240vac circuit, and those tend to be dedicated to a specific appliance. US code requires the 80% rule, so on a 15A circuit, the most you can use continually is 12A, or 80%. Something plugged in for more than 3-hours, triggers that rule, one often ignored when using something like space heaters, sometimes, to the operator's peril. Intermittent use at up to the max is allowed, but not continuous use of more than 3-hours.

Moving to a different garage wall socket solved the problem ... 12+ hours of cool plug charging

I was much too close to a dangerous situation

Feeling lucky !!!



Will replace the socket and wires tomorrow

BTW they are copper