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If you don't want to watch a 7 minute video, I'll summarize it.
"Use a 5-20 outlet instead of a 5-15."
"Use a 5-20 outlet instead of a 5-15."
If you don't want to watch a 7 minute video:
"Use a 5-20 outlet instead of 5-15."
"Use a 5-20 outlet instead of 5-15."
jelloslug
Active Member
There is not a single forum for battery / charging and I thought it was relevant information for S,3,x owners. If that offends you well, move along.
It is poor etiquette to cross post the same thing in multiple places. It’s really best to find the one spot that you think is best and post there, even if it fits in multiple categories.
It’s also poor etiquette to post a clickbait title and just link to a video with no explaination. This and the cross posting just comes across as someone desperate to get views and isn’t going to make you many friends here.
If you really want to benefit the community you can post it once and add a quick sentence or two explaination with the video... “You can charge faster by charging at 20 amps instead of 15... watch this video for more details”. That way people who are interested in the video can watch it and learn and those who are already know about it don’t have to waste their time clicking through.
I see now that we do have a videos forum for youtube etc.. In the future I'll just put videos in there.
dhanson865
Well-Known Member
Heck I'll give him an upvote for using 120v (what we have in the US) verbally and in written form instead of 110v (what some other countries have over seas).
I'd give him another vote for not using back stab outlets and for the fact that he gave enough information that someone might replace a worn outlet and/or replace a breaker.
Personally I'll never use a 5-20 for my car because my 14-50 socket is right next to it. But if he helps someone that doesn't know the proper US voltage or that needs to replace worn out parts then it's a small plus for fire safety.
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dhanson865
Well-Known Member
I notice you are seeing 117v while charging at the end of the video. You might want to check your wiring size / breaker quality and to make sure something on your end isn't causing the voltage drop.
If it is outside your house you should notify your utility. It's not uncommon in older neighborhoods to have overloaded transformers. 114v is the minimum spec for 120v per ANSI C84.1 but anything that far below 120v catches my eye and if you do see less than 117v I'd be all over someone to get that addressed ASAP. I tend to see 119-123v at my house (partly because I replaced most of the inefficient lighting, appliances, and HVAC reducing my load on the meter and transformer).
Low input voltage is hard on the electronics of most all the devices in your house and in most cases causes more waste heat because the internals are more efficient at high voltages (for example desktop PC power supplies get more efficient the higher the voltage).
I really don't get your high level of concern over 117V. Allowable ranges for the input from the utility to your house would be 120V + or - 5%, so as you point out, 114V would still be allowed coming into your house. And any wiring run beyond that in the house itself is going to have about 1 to 2V drop anyway by the time it gets to an outlet/appliance. 117V while loaded and drawing current is extremely close to nominal and is of no concern at all.
dhanson865
Well-Known Member
Running low input voltage ages equipment and will cost you in replacement equipment (forced upgrades due to premature end of life) all while producing more waste heat and using ever so slightly more electricity (making your utility bill higher).
For a typical desktop PC power supply with the computer at full load the efficiency at 120v vs 110v looks like
120V 84.4%
110V 83.7%
But the effect is exaggerated at lower loads as the PSU gets less efficient.
And that is for a high quality desktop PC PSU, many devices in your home have much cheaper less robust power supplies that don't handle brownouts or near brownouts as efficiently.
Then there is the AC feedback loop if you live in a warm climate. That is waste heat causing you to run the AC more, using more power because of the original inefficiency. How efficient is that multi ton heat pump at low input voltages?
an extra 0.5% or 1% or more times all the loads in your house would cost hundreds of watts. It might be a dollar a month if your electricity is very cheap but some people pay more for electricity.
davewill
Active Member
In the video, he has a 20a circuit with only one outlet on it that he changes out to a 5-20. He could have changed the breaker and the outlet and had a 6-20 which would have nearly tripled his charging speed.
That statement may be totally factually correct....but is also totally irrelevant, because 117V from a nominal 120V supply isn't in any way close to being considered "low". Your suggesting to call the power company over a 2.5% variance is ridiculous.
Oh yeah, that hadn't even occurred to me, but that's absolutely true. It's not usually something you think of, because 120V outlets don't usually have just one outlet on the circuit.
If you really want more juice out of a 120v outlet, replace the single pole breaker with a 2-pole 15A breaker and switch the formerly neutral wire to a hot pole. You must verify that the outlet is the only outlet fed by the breaker or you must decommission those outlets accordingly. Also label your wires accordingly.
That's what @davewill is suggesting above. Have to buy/make a NEMA 6-20 to NEMA 14-50 adapter and set the amperage manually, though.
The video would have been longer...
dhanson865
Well-Known Member
The thing is this is winter and he is likely to see worse voltages when it is hot outside in the summer.
Notice he is in Miami, FL which is a bit warmer than your Boise, ID.
Notice also I said "if you do see less than 117v" not if you see 117v.
And if you think I'd call the utility first, that is a reading comprehension problem, go back up thread and you'll see I said to check the wiring in the circuit first and the breaker before looking at the utility.
Here are some pictures from a car 120v charging on substandard wiring (14 gauge instead of 12 gauge). This guy almost had his house burn down. He had to have the fire dept put this out.
Guess what the first symptom of substandard wiring is before the fire starts? It's lower than expected voltage. And as the wire heats the voltage drops and the amps increase to compensate. The breaker will trip eventually. But the big question is, will the breaker trip before or after something hits the smolder point?
So when you start charging if the voltage is below 120v, the first thing I'd do is monitor the charge session and see if the voltage drops further. If it got to 117v or below I'd unplug the EVSE and grab an IR thermometer and or a way to read voltage from the jack and start checking things out.
Or if you prefer you can just wait for it to let the smoke out.
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