GMC · 2025
Sierra EV AT4
Off-road electric truck. Here's what its onboard charger actually needs from your home's electrical panel.
Home (Level 2) charging facts
Pulled straight from the Sierra EV AT4's onboard charger rating - not a generic EV number.
- Onboard charger draw
- 19.2 kW
- ~80A at 240V (kW × 1000 ÷ 240)
- Empty-to-full at max Level 2
- 8.9 hrs
- 170 kWh battery ÷ 19.2 kW
- Range added per hour
- ~40 mi/hr
- 19.2 kW × 2.1 mi/kWh efficiency
- DC fast charging
- 350 kW max
- Public chargers only - tapers as the battery fills
Typical full-speed install
80A charger on a 100A circuit
Reaches this car's 19.2 kW ceiling. Whether your panel has room for that circuit depends on everything else already on it - that's the actual assessment.
Connector
CCS
CCS (Combined Charging System) is the most common connector on non-Tesla EVs for both home Level 2 charging and public DC fast charging.
On the Sierra EV AT4 specifically, that connector carries up to 19.2 kW at home on Level 2 and up to 350 kW on public DC fast hardware.
Charging speed by circuit size
None of these common home circuit sizes reach this car's 19.2 kW onboard ceiling - it can use every amp up to 48A.
| Charger setting | This car actually draws | Range added / hour | 8-hr overnight |
|---|---|---|---|
| 16A | 3.8 kW | ~8 mi | ~64 mi |
| 24A | 5.8 kW | ~12 mi | ~96 mi |
| 32A | 7.7 kW | ~16 mi | ~128 mi |
| 40A | 9.6 kW | ~20 mi | ~160 mi |
| 48A | 11.5 kW | ~24 mi | ~192 mi |
Overnight, at full onboard speed
320 mi / 8 hrs
400 mi across a 10-hour window, at 19.2 kW.
Approximate cost to fill from empty
$22.10
Assumes $0.13/kWh (a national-average estimate, not your local rate) × 170 kWh - about $0.062/mile.
GMC Sierra EV charging questions
How long does it take to charge a 2025 GMC Sierra EV AT4 on a Level 2 charger?
About 8.9 hours from empty to full at its 19.2 kW onboard-charger ceiling (170 kWh battery ÷ 19.2 kW).
Times scale with amperage - see the circuit-size table above for other settings.
What amperage does a GMC Sierra EV draw on Level 2?
At its full 19.2 kW rate, the GMC Sierra EV draws about 80A at 240V (kW × 1000 ÷ 240 = amps).
Can a GMC Sierra EV use a 48-amp charger?
Yes, and it'll use the full 48A. A 48A charger delivers ~11.5 kW, which is at or under this car's 19.2 kW ceiling - about 24 mi of range per hour.
How much range does a GMC Sierra EV add per hour on a Level 2 charger?
About 40 miles of range per hour at its 19.2 kW ceiling (19.2 kW × 2.1 mi/kWh efficiency).
How much range does an 8-hour overnight charge add to a GMC Sierra EV?
Roughly 320 miles from an 8-hour overnight charge (40 mi/hr × 8 hours), or about 400 miles across a 10-hour window.
What's the DC fast charging ceiling for a GMC Sierra EV?
Up to 350 kW on a public DC fast charger - well above its 19.2 kW Level 2 (home) ceiling, though DC fast rates taper as the battery fills.
Other GMC EVs
Will your panel handle this?
ChargeRight runs the full NEC load calculation against your actual panel - not a generic rule of thumb.
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