GMC Hummer EV Battery: Complete Guide
The GMC Hummer EV battery is one of the largest in any production vehicle — a 212.7 kWh usable Ultium pack in the top 3X trims, using 24 modules of GM’s NCMA chemistry in a pack that drives at 400V and series-switches to 800V for fast charging. This massive battery enables up to 363 miles of range (Pickup) and supports 350 kW DC fast charging that adds nearly 100 miles in 10 minutes.
The Hummer EV is also exceptionally inefficient — consuming roughly 57.8 kWh per 100 miles versus a Tesla Model Y’s 26.8 — meaning it needs that enormous battery just to achieve competitive range, and shares its BT1 truck platform with the GMC Sierra EV. This guide covers the Hummer EV battery’s full specs, charging, the 800V series architecture, and what its size-versus-efficiency tradeoff means for owners.
Quick answer
The GMC Hummer EV uses GM’s Ultium NCMA pouch-cell pack in two sizes: a 24-module pack with 212.7 kWh usable (246 kWh gross) and a 20-module pack with about 170 kWh usable. The big pack weighs 2,923 lb, enables up to 363 miles of range and charges at up to 350 kW; a new replacement pack fitted runs roughly $25,000–$40,000, and GM’s warranty is 8 years / 100,000 miles with a 75% capacity floor.
Key figures: 212.7 kWh usable (24-module) · ~170 kWh (20-module) · up to 363 mi · 350 kW DC peak · 8 yr / 100,000 mi warranty, 75% floor
GMC Hummer EV Battery: Full Specs (2026)
| Variant | Battery (Modules) | Usable Capacity | EPA Range | Peak DC Rate | Power |
|---|---|---|---|---|---|
| Hummer EV Pickup 2X | 20 modules | ~170 kWh | up to 316 miles | 350 kW | 625 hp |
| Hummer EV Pickup 3X | 24 modules | 212.7 kWh | up to 363 miles | 350 kW | 830 hp |
| Hummer EV SUV 2X | 20 modules | ~170 kWh | up to 319 miles | 350 kW | 625 hp |
| Hummer EV SUV 3X | 24 modules | 212.7 kWh | up to 314 miles | 350 kW | 830 hp |
The two packs in full: the 24-module pack holds 246 kWh in total, of which 212.7 kWh is usable, and weighs 2,923 lb; the 20-module pack holds about 178 kWh in total, about 170 kWh of it usable, and weighs about 2,436 lb. AC charging is 11.5 kW on most trims, with a 19.2 kW onboard charger available. Cars with the Extreme Off-Road package (larger tires) are rated below the range figures above — check the window sticker of the specific truck.
Inside the Hummer EV’s Massive Battery
The Hummer EV uses GM’s Ultium battery platform with NCMA (Nickel Cobalt Manganese Aluminum) chemistry — the same cells used across GM’s electric lineup. The top 3X Pickup uses 24 modules of large-format pouch cells — 576 cells in total — holding 246 kWh gross, of which 212.7 kWh is usable. The pack is built on GM’s BT1 truck platform, the same platform underpinning the Chevy Silverado EV and GMC Sierra EV.
The Hummer EV’s standout engineering feature is its 800V series-charging architecture. The battery operates as two 400V packs during driving, then reconfigures into series 800V when DC fast charging. This allows the Hummer to accept up to 350 kW charging despite its base 400V drive architecture — recovering nearly 100 miles of range in 10 minutes. GM also uses wireless communication between battery modules — a unique approach that eliminates much of the wiring harness complexity in a pack this large.
It is also the heaviest battery ever fitted to a production EV. GM’s EPA filing lists the 24-module pack at 2,923 lb — about 32% of the Edition 1 pickup’s 9,063 lb curb weight; the 20-module pack weighs about 2,436 lb. The two layers sit in a stamped-steel enclosure: a Munro teardown counted roughly 139 stamped components and some 3,500 welds in its structure. For context against the rest of the market, see how much an EV battery weighs across today’s electric cars.
The Efficiency Problem: Why Such a Big Battery?
The Hummer EV needs its enormous battery because it is one of the least efficient EVs ever made. On independent range testing, the Hummer EV consumed 57.8 kWh per 100 miles — 8.6 kWh/100 miles higher than the next-most-inefficient EV (the related Chevy Silverado EV RST), and more than double the Tesla Model Y’s 26.8 kWh/100 miles on the same route.
This inefficiency comes from the Hummer’s extreme weight (9,063 lb curb weight in Edition 1 pickup form), boxy aerodynamics, large off-road tires, and high power output. The 212.7 kWh battery is necessary just to deliver a competitive 363-mile range from such an inefficient vehicle. For comparison, the Lucid Air achieves 516 miles from a 112 kWh battery — less than half the Hummer’s pack size — because it is roughly 3x more efficient.
The practical implication for owners: charging costs are high. A full charge of the 212 kWh pack costs significantly more than charging a typical EV, and the Hummer uses far more electricity per mile driven. Buyers choose the Hummer for its capability, presence, and off-road prowess — not efficiency.
GMC Hummer EV Charging Speeds
| Charging Method | Power | 212.7 kWh Pack (3X Pickup) |
|---|---|---|
| Level 1 (120V) | ~1.4 kW | Multiple days (impractical) |
| Level 2 (240V, 19.2 kW) | 19.2 kW | ~13–14 hours full |
| DC Fast (150 kW) | 150 kW | ~90 min (10–80%) |
| DC Fast (350 kW, 800V) | 350 kW peak | ~100 miles in 10 min; ~45 min (10–80%) |
The 350 kW peak depends on the series-switching described above: the pack charges as an 800V system even though it drives as a 400V one, and it can also charge on 400V infrastructure at lower rates. In an independent test the truck peaked at 344 kW and charged from 21% to 80% in 34 minutes. On AC the picture splits by trim: the standard 11.5 kW onboard charger needs roughly 19 hours for a full 24-module charge, while the available 19.2 kW unit (shown in the table) cuts that to about 13–14 hours.
Bidirectional Charging and Vehicle-to-Home
The Hummer EV supports bidirectional charging — Vehicle-to-Home (V2H) and Vehicle-to-Load (V2L). With compatible equipment, the massive 212.7 kWh battery can power a home during an outage for an extended period, run tools and equipment off-grid, or even charge another EV. The huge pack makes the Hummer one of the most capable mobile power sources of any consumer vehicle — a full charge holds enough energy to power an average American home for over a week.
GMC Hummer EV Battery Warranty and Degradation
GM covers the Hummer EV battery with an 8-year / 100,000-mile warranty against defects and capacity loss below 75% of original — the 75% floor is printed in GM’s own EV warranty booklet (many websites quote 70%, which is the floor some other brands use, not GM’s).
- Low cycle depth: A 212 kWh pack means each daily drive uses a small percentage of total capacity — most owners rarely deeply cycle the battery, which slows degradation
- What to expect over time: There is no large independent degradation dataset for the Hummer EV yet. Ultium packs in GM’s other EVs show small early losses, and the Hummer’s shallow cycling should help — but treat any specific percentage for this truck as an estimate, not data. In normal use the pack is expected to serve 10 years or more.
- Heat management: Active liquid cooling protects the pack; like all NCMA batteries, avoiding parking at 100% in hot climates extends life
- Large buffer advantage: Even significant absolute capacity loss leaves substantial usable range given the pack’s enormous starting capacity
GMC Hummer EV Battery Replacement Cost
There is no official GM price for a Hummer EV replacement pack, so any figure is a planning estimate. For a new full pack fitted at a dealer, budget roughly $25,000–$40,000 depending on which pack the truck has — the 24-module unit is the largest and most expensive battery GM fits to any vehicle. Online estimates of $20,000–$30,000 usually quote the pack alone, before labour, ancillary parts and taxes.
Most owners will never pay it. The 8-year / 100,000-mile warranty covers the pack down to 75% capacity, GM dealers service these sealed packs at module level where a repair is possible, and a thin used market in salvaged Ultium packs exists for out-of-warranty trucks — prices there move too fast to quote as a guide figure. If a dealer quotes a full-pack replacement on an out-of-warranty truck, get the module-level diagnosis in writing first.
Read more: our EV battery replacement cost guide breaks down pack prices across brands.
The Hummer EV’s 12-Volt Battery
Like every EV, the Hummer EV also carries a conventional 12-volt battery — an AGM unit (Group 94R class; confirm the exact fitment by VIN) that runs the computers, locks and displays while the high-voltage pack keeps it topped up. Expect about 3–5 years of life. A weak 12-volt battery can trigger misleading warnings — including ‘service high voltage battery’ messages — or a no-start, so it is the first thing to check before fearing a high-voltage fault. Aftermarket lithium and sodium 12-volt replacements exist as an owner option.
Hummer EV vs Other Electric Trucks: Battery Comparison
| Truck | Battery (Usable) | EPA Range | Efficiency (kWh/100mi) | Peak DC Rate |
|---|---|---|---|---|
| GMC Hummer EV 3X Pickup | 212 kWh NCMA | ~363 miles | ~57.8 | 350 kW |
| Chevy Silverado EV RST | 205 kWh NCMA | ~440 miles | ~49 | 350 kW |
| Rivian R1T Max | 140 kWh NCA | ~410 miles | ~34 | 220 kW |
| Ford F-150 Lightning ER | 131 kWh NMC | ~320 miles | ~41 | 155 kW |
| Tesla Cybertruck AWD | ~123 kWh | ~325 miles | ~36 | 250 kW |
Full specs for the Rivian and Ford rivals above are in our Rivian R1T battery guide and Ford F-150 Lightning battery guide.
Charging Tips for GMC Hummer EV Owners
- Charge to 80% daily: Even with the massive pack, limiting daily charging to 80% preserves NCMA battery health. 80% of 212.7 kWh still provides ~170 kWh — far more than most daily driving needs.
- Use 800V DC fast charging on trips: The series-charging architecture’s 350 kW capability is essential for the large pack — a 150 kW charger takes about 90 minutes for 10–80%, while 350 kW cuts that roughly in half.
- Install a 19.2 kW Level 2 charger: Given the pack size, a high-power home charger is worthwhile — a standard 11.5 kW charger takes significantly longer to fill the 212.7 kWh battery overnight.
- Budget for higher charging costs: The Hummer’s inefficiency means higher electricity costs per mile than any other EV — factor this into ownership cost calculations.
Frequently Asked Questions
What battery does the GMC Hummer EV use?
GM’s Ultium pack: NCMA pouch cells in a double-stacked, two-layer layout. Two sizes exist — a 24-module pack (246 kWh gross, 212.7 kWh usable, 576 cells) and a 20-module pack (about 170 kWh usable).
What is the difference between the 20-module and 24-module Hummer EV packs?
Capacity, range and weight. The 24-module pack gives 212.7 kWh usable, up to 363 miles in the Pickup and up to 314 in the SUV, and weighs 2,923 lb. The 20-module pack gives about 170 kWh usable, up to 316–319 miles depending on body, and weighs about 2,436 lb. Both charge at up to 350 kW.
How much does the Hummer EV battery weigh?
2,923 lb for the 24-module pack — GM’s figure from its EPA filing, and about 32% of the Edition 1 pickup’s 9,063 lb curb weight. The 20-module pack weighs about 2,436 lb. It is the heaviest battery in any production EV.
Does the Hummer EV really charge at 800V?
Yes — for charging. The pack drives as two 400V layers in parallel; for DC fast charging, internal switches re-wire the layers in series to 800V, which is how it reaches its 350 kW peak. It can also charge on 400V infrastructure at lower rates.
How much does a Hummer EV battery replacement cost?
GM publishes no official price. A new full pack fitted at a dealer runs roughly $25,000–$40,000 as a planning figure (online $20,000–$30,000 estimates are usually pack-only, before labour and parts). Most owners pay nothing: the warranty runs 8 years / 100,000 miles down to a 75% capacity floor, and many faults are repaired at module level.
How long does the Hummer EV battery last, and what does the warranty cover?
The warranty covers 8 years / 100,000 miles against defects and capacity loss below 75%. There is no large independent degradation dataset for this truck yet; Ultium packs generally show small early losses, the pack’s shallow cycling helps, and in normal use it is expected to serve 10 years or more.
Conclusion
The GMC Hummer EV battery is a study in extremes — a 212 kWh Ultium NCMA pack, one of the largest in any production vehicle, with innovative 800V series-charging that enables 350 kW DC charging despite a 400V drive architecture. Buyers wanting the same BT1 platform in a more traditional pickup body should see our GMC Sierra EV battery guide. The enormous battery is necessary because the Hummer is among the least efficient EVs ever made, consuming roughly double the energy per mile of an efficient sedan.
For buyers who prioritize capability, off-road performance, and bidirectional power over efficiency, the Hummer EV’s battery delivers — but with high charging costs and an environmental footprint that comes with moving 9,063 lb of electric supertruck.
