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Discussion Starter #1 (Edited)
I was checking the tire pressure on the Volt while it was charging and noticed that the charging cord was pretty warm. Ambient air temp in the garage was 60f. Charger cord temp was 108.5. I obtained that by pinching the temp probe between two of the coils and holding it there. I suspect the actual temp was even higher than that. When checking temps on A/C lines we usually stick it under a piece of insulation to get a good number. At a minimum this implies a fair amount of wasted energy being converted to heat.

Wish the cord was thicker gauge... my Voltec is only like 2 ft from the charge port on the Volt. Wonder how difficult to replace the cord with something thicker?


I would guess the vehicle had been charging for 1.5 hours. And the batt was fully depleted at the start of the charge. Outside air temp was probably around 40f.

Anyone else noticed their charger cord getting hot?
 

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Anyone else noticed their charger cord getting hot?
I'd say warm, not hot. On those instances where I've got the EVSE plugged in to a 50' 12/3 extension, the EVSE cord is noticably warmer than the extension. I hope they're at least using 14 gauge. It doesn't look like they're using 12.
 

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16 gauge wire to blame

If you look carefully at the wire labeling, GM is using 16 gauge. Mine runs VERY warm, almost to the point where you cannot hold onto it firmly. The only way mine will work is to plug it into a 20 amp dedicated line or run it in out in the cold. Something is triggering my charger to stop, flash indicator lights, blow the horn and failing to complete the charge cycle after the wire heats up when plugged into a 15 amp circuit.

When I bring the subject up to various electricians, they are surprised that GM didn't use 14 gauge wire. The construction of the Voltec makes it appear that the case cannot be opened, so it will require replacement instead of modification when the dealer is contacted for a warranty repair. Because it does work in the one dedicated outlet, I am hoping to replace after obtaining the 240 volt charger. Now that SCE has modified their online videos, I will be trying to call SPX once again to schedule a visit from Edison. I've ordered a limited edition GE WattStation too, but those aren't ready for shipping just yet. Service Magic will be installing the WattStation.
 

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I feel a bit ripped off on this. I mean, them deciding to use smaller wire = more money out of our wallet and energy used for every Voltec sold! being wasted as heat. :( It will really suck in the summer time. I haven't even checked mine, I just assumed it was ok. I am such a moron, I didn't even check the wires inside the voltec when I installed. They didn't like.. catch my attention when I wired the 10-3 up to it. They install basically right next to each other in the box.
 

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Kind of reminds me of a story from my college days. One of the young ladies in my dorm asked my advice on buying a set of jumper cables. Not wanting to go into the details of ohms law I just told her to buy the most expensive shortest set and not be suckered into buying a long set of cables with a really good price because they would be junk. It was only later I realized what a nerd I was and what she really wanted was for me to go with her to shop for them. But given enough time I'm a pretty quick thinker. All was not lost though and now I am married to that same girl 25 years later!
 

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Discussion Starter #7
Anyone know of a source for SAE J1772 Plugs so the cord could be replaced with something appropriate?
 

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16 gauge wire plugs into the wall

I am referring to the 120 volt charger that is included with every Volt.

The wire that gets hot plugs into the wall. It is NOT the long wire with the J1772 connector. That one stays cool.

To see the entire length of the plug in the wall wire, slide the wall bracket off the back and notice how the wire exits the charger out the back at the center. The wire can exit the wall mount at the top or bottom.
 

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My math is always suspect but, assuming a 10' 16 gauge cord (20' round trip) at 4.02 ohms/1000', the power lost while charging at 15 amps from 120 volt circuit is about 18 watts (current squared * resistance), about a 1% loss.

Using the same suspect math, if the charging cord were constructed with 12 gauge wire at 1.59 ohms/1000', the loss would be about 7 watts or 0.39%.
 

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Honestly, I'm sure the cord is fine even though it gets warm. The insulation on the cord is probably rated for around 200+F, so you have a long way to go to get to that temperature. As long as the car charges, doesn't burn you, and doesn't catch fire who cares if it gets hot?
 

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OH! I am so sorry. I thought you meant the 220. HAHA, when I hear Voltec Charger, that is what I think of.
 

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Discussion Starter #12
My math is always suspect but, assuming a 10' 16 gauge cord (20' round trip) at 4.02 ohms/1000', the power lost while charging at 15 amps from 120 volt circuit is about 18 watts (current squared * resistance), about a 1% loss.

Using the same suspect math, if the charging cord were constructed with 12 gauge wire at 1.59 ohms/1000', the loss would be about 7 watts or 0.39%.
So if the 220v Voltec uses the same size cord, and we have two "hot" lines does that mean we have 18 watts wasted on each line for a total of 36 watts of wasted energy for the 220v charger?
 

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I think many Volt owners, current (heh) and future, care a great deal about energy conservation, ergo energy wasted while charging is less than desirable, and seems slightly out place for an eco-car.
 

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Discussion Starter #14
"Current Volt owners" ... good one. Got a charge out of that.

Check on the 220v Voltec cord. It uses a 14 gauge cord.

Still, I agree for $490 I think a 12 awg or better should have been used on the 220v charger.
 

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Negative (hah) Marc Lee. I like to think of a 120 volt circuit having a neutral lead that remains at ground potential while the "hot" lead goes positive, then negative, rinse, lather, repeat. With a 240 volt circuit we have two hot leads 180 degrees out of phase so when one is +120 volts the other is -120 volts, hence the 240 volt differential.

Regardless, heat loss is proportional to the current squared times resistance, if current remains at 15 amps, and the resistance remains the same, the power loss will be the same, 18 watts. The impact on efficiency however will be less, half as much or 0.5%, because there's twice the power.
 

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Whoah. this is why I failed electronics class. :) If you find a link that explains this in a fun informative factor share it! Cause it sounds intriguing.
 

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Discussion Starter #17
Negative (hah) Marc Lee. I like to think of a 120 volt circuit having a neutral lead that remains at ground potential while the "hot" lead goes positive, then negative, rinse, lather, repeat. With a 240 volt circuit we have two hot leads 180 degrees out of phase so when one is +120 volts the other is -120 volts, hence the 240 volt differential.

Regardless, heat loss is proportional to the current squared times resistance, if current remains at 15 amps, and the resistance remains the same, the power loss will be the same, 18 watts. The impact on efficiency however will be less, half as much or 0.5%, because there's twice the power.
Are you positive? (ta dum ding) Hmm hard to believe you can heat a 25' cord 50f above the ambient temp with only 18 watts.

The 12 gauge wire I ran from the panel to the 220 Voltec does not heat up at all.
 

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Well, the power dissipated as heat due to resistance and current is watt it is (gotcha), just how heat translates to temperature differences is an area I'm substantially untutored in. I wish it were not so.
 

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For the 120 volt charger, I am using a fan to cool the 120 volt wall plug, supply cord plus the back of the charger. Seems to have solved my overheating problems as the Volt now charges faster than ever with NO horn honking or charger failures. A small built in fan should have been originally engineered into the charger to cool the electronics.

Now I know why the charger worked at other locations. It was always outside getting a breeze or colder temperatures. At home, it's in the home or garage with no breeze. Once the fan was aimed at the charger; problem solved. I bet my unit has an improper stripping of the supply cable wires. If some strands of copper were cut off, the supply cord would overheat due to the fuse like properties of a smaller wire gauge for that short distance. The additional heat could heat up internal components, causing charger faults and failures. It's just a thought, but one that I will discuss with GM in hopes they will research the problem when exchanging the defective charger.
 
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