Right! Or, more formally, I=E/R. If the load could command a certain wattage, then current would rise as voltage drops, but it can't. So that formula is P=Esquared/R. Either way, as resistance goes up, voltage drops and so does power.
Do note that with the widespread use of switch mode power supplies today, there are lots of loads that can command a certain wattage, or a certain current, regardless (almost) of the line resistance. These can make mincemeat of the old resistance rules, so some devices really do appear to have negative resistance, i.e. load current increases when input terminal voltage drops.
Correct. You can design the controls in a switching power supply to regulate almost anything you want. Voltage is the most common but some regulate current and every battery charger does both depending on where you are in the charge cycle (current at the beginning, voltage at the end).
Good point. In California you are asked to charge at night because the grid is too weak. Also, you are used to spending when you buy a new car, so cough up a few bucks for a “dedicated” extension cord. BTW, is there such a thing as an in line thermal breaker, in stead of relying on the breaker in the box?
The Toyota charging cable has a temperature sensor in the plug (also linked in #23 above). Commercially-available, in-line GFCI devices typically provide only ground-fault protection, not overcurrent protection (thermal, thermal-magnetic, electro-synthe-magnetic, or otherwise) but I suppose one could put a miniature circuit breaker or supplementary protector into a small enclosure with cable glands. To be clear, I don’t recommend using extension cords for EV charging at all. (EV operation is fine, of course.)
Southwire E-238 Heavy Duty Power Station Cord reel, with 6 Grounded Outlets, 12/3 50-Foot Extension Cord, Built In 15-Amp Circuit Breaker, Green/Black https://a.co/d/j57pf8g
Hello, Looking for safety confirmation on the following charging config: Apartment detached garage using a GFCI outlet, unknown amp rating of circuit and gauge of wiring to outlet. From outlet I am using a 14 AWG 50ft 15A all copper extension cord. Purchased from Lowe's at about $37 See cord details below: primewirecable /collections/general-purpose/products/ec50173050ft-14-3-sjtw-orange-outdoor-extension-cord Weirdly the copper statement is on a different page: primewirecable /blogs/news/ten-quality-reasons-to-buy-prime I believe I fall within the safety margins but have not taken temperature readings at the connector housing. Any and all feedback appreciated.
Do you have insurance that covers electrical fire? Did you read the owners manual that came with the car about using extension cords and EVSE safety? You already know where the visual signs of trouble will show up, but you are also missing key information about the circuit between the service drop and the GFCI outlet, were the issue(s) you can't see can occur. Use at your own risk !
IMHO; 14-3 is too small!!! People here stating that there's only 14G in the walls as an excuse, obviously aren't electrician or engineers. 14G in the walls are solid copper core; NOT stranded questionable material cheap extension cords! Vendor's tend to exaggerate their specifications and that cable is going to draw 12A @ the end of that charge cable. You need to find out what other appliances are plugged into that circuit, because your likely to blow it. Your only 2-3A from blowing that breaker because that extension cord is drawing more current at the wall outlet than coming out at the other end. You need to go down to a 12-3 yellow construction extension cord at 25 feet max.. That along with your 20+ feet charge cable should be more than enough. The shorter cord will lower voltage and current drops across the entire length. Safer to operate and check for connection heat-ups 0.5 to a hour into charging - They shouldn't be warm; otherwise you have a problem brewing!!! Hope this helps... FWIW; I had to replace the ends on my construction extension cord because it was heating up - bad connections = high resistance = heat. Those cheap extension cords need to be checked on a regular basis, otherwise best case you just pop a breaker - worse case you burn down your garage/home.
