You plugged in before bed, and the cable still sits in the port. Dawn hits the driveway and the percentage hasn’t moved. In the Las Vegas Valley that usually isn’t a ruined pack. It’s a charge window that never opened. It can be a silent wall unit. It can also be a 12-volt battery that slept through the heat.
Valley nights don’t dump yesterday’s heat after a long day. NWS Las Vegas puts the average July high at 104.5F. About 78 days a year reach 100F or more. About 9.4 days a year reach 110F. The all-time record high is 120F, set on July 7, 2024. Driveway concrete and garage slabs hold that load after dark. Harry Reid International Airport runs 5 to 15F warmer than outlying areas. East valley and downtown can run 11F hotter than the rim. A car in Winchester or Paradise sits warmer overnight than one in Summerlin. Summerlin sits near 3,500 feet and climbs toward Red Rock. That’s why a quiet charge looks like a dead pack at 6 a.m.
Overnight power here follows a named window
Most valley addresses sit on NV Energy, Nevada Power Company. NV Energy publishes a Residential Electric Vehicle Recharge Rider. That rider’s EV charging window runs from 10:01 p.m. to 8:00 a.m. You enable that window once and then forget it. You get home late from a Strip night in Paradise or Winchester. You plug in at 11:30 and the car may still wait. If you leave at 7, you only caught part of the night. The dash can say charging while the car is only waiting.
Nevada has no retail electric choice for homes. Voters rejected Question 3 in 2018, so you stay put. Boulder City Utilities is Boulder City’s own municipal electric service. It runs largely on Hoover and Glen Canyon hydro. Blue Diamond, Indian Springs, and Sandy Valley sit on Valley Electric Association. Moapa Valley, Overton, Logandale, and Moapa sit on Overton Power District No. 5. Don’t call NV Energy if that’s not who serves you. Confirm your overnight window with the utility on your bill. No rate figure is published on this site. Ask them for the current plan rules before you change the car.
NV Energy also runs a Residential Managed Charging Program. The handbook was revised on July 29, 2026. If you enrolled, the utility can shift when the car draws. A managed session can look idle until the program allows it. Check the car’s schedule and that enrollment before you blame the hardware.
Heat puts the 12V to sleep first
The high-voltage pack doesn’t start the charge session. The 12-volt battery runs that computer instead. If the 12V is weak, the car can look plugged in and do nothing. Valley heat is hard on that small battery. You plug in hours before 10:01 p.m. The car drops into a low-power sleep. The charge latch stays closed on the port. The wall unit may still show a ready light. At sunrise the percentage is the same.
Wake the car before you assume the EVSE failed. Open a door, unlock with the fob, or start climate from the app. If charging begins a few minutes later, sleep was the issue. A weak 12V can cause the same stall. If this repeats a few nights, the 12V is tired. That still isn’t the high-voltage pack. Tesla 12V failure in valley heat explains how desert heat wears that battery. What happens when an EV’s 12-volt battery dies in the valley covers the warning signs. Operators we connect you with can jump or replace a dead 12V. They handle Tesla and every major EV brand.
Check the app before you blame the pack
Open the app and the center screen first. Look for scheduled charging, departure time, or off-peak charging. Confirm the window actually opened while you slept. Check the charge limit on the app. An 80 percent cap can look like a failed overnight fill. You may have wanted 100 percent for a Lake Mead morning. Unplug the cable, then reseat it fully. Listen for the port to click in place. A ready wall light and a quiet car often mean a loose latch. Look at the breaker and the GFCI next. If the circuit died at 2 a.m., the EVSE had nothing to send. Reset it once, and stop if it trips again.
If a session started and then froze at a random number, that isn’t a missed window. That’s an interrupt in the heat, not a closed window. Why EV charging stopped at a random percentage in the heat covers that pattern.
When the house side actually failed
Home cables back out when the cord is short or under tension. Reseat the plug fully until it clicks. Winchester and Boulder City have some of the valley’s oldest housing. ACS 2019-2023 figures put that share at 53.1 percent and 48.5 percent. That’s a garage and panel proxy, not a diagnosis of your circuit. An older garage run can still trip a Level 2 load overnight. Clark County’s Title 30 code requires EV-ready wiring in new construction. A Level 2 home charger needs an electrical permit. If the breaker keeps tripping, get the circuit inspected. Why your Level 2 charger keeps tripping the house breaker is the next read.
If you still have to leave on a thin pack
July mornings in the valley don’t forgive a guess. Recurrent Auto found about 5 percent range loss at 90F. The same work found 17 to 18 percent loss at 100F. Cabin cooling drew 3 to 5 kW in that work. AAA, in May 2026, measured 8.5 percent range loss at 95F. Those range figures aren’t from Tesla. Tesla didn’t publish a range-loss number we could cite. Don’t treat the dash estimate as a lock on I-15 or US-95.
If remaining range is too thin, skip the driveway debate. Charge Pro LV is a referral line. We match stranded EV drivers with independent local mobile rescue operators. We don’t own trucks or employ technicians. We don’t set prices or promise an arrival time. The operator quotes you before starting and bills you directly. Operators bring a 240-volt Level 2 source to the car. Tesla uses a native NACS plug. Other EVs use a CCS or J1772 adapter. They typically add 10 to 20 miles of range. That takes 15 to 30 minutes of charging. That’s charging time, never an arrival time. Mobile EV charging is the page for that match. When 240-volt charging at home isn’t an option covers that roadside source.
We serve every city in the valley. If you need a match, call (702) 935-4699. We’ll connect you with a local operator.
Why did the car say it was charging if the percentage never rose?
The window often hadn’t opened yet overnight. Or the charge limit was already met. Check the app schedule and the set limit first.
Can the pack sit on a live cable all night without drawing power?
The software can wait on a schedule, a managed program, or a sleep state. Sitting on a cable without current isn’t a charge session.
Should I keep resetting the breaker if the charger is dead at dawn?
Reset it once, and stop if it trips again. A breaker that keeps opening is protecting the circuit. Get the panel inspected before you restore the load.