The GMC Hummer EV is many things, ludicrously quick, hilariously wide, and heavy enough to bend gravity in nearby ZIP codes. Under all that theater is the Ultium battery pack, the single most expensive component in the truck. Understanding the GMC Hummer EV battery warranty details isn’t just paperwork trivia; it’s how you protect tens of thousands of dollars in high‑voltage hardware.
Quick take
GMC Hummer EV Battery Warranty at a Glance
Core Hummer EV Warranty Numbers
GMC doesn’t reinvent the warranty wheel just because the Hummer EV is outrageous. It uses the same basic template as other modern GM EVs: a standard 8‑year/100,000‑mile high‑voltage battery and electric drive warranty, paired with a 3‑year/36,000‑mile bumper‑to‑bumper warranty and a 5‑year/60,000‑mile powertrain and roadside assistance package.
How Long the GMC Hummer EV Battery Warranty Lasts
For both the Hummer EV Pickup and Hummer EV SUV sold in the U.S., the Ultium battery and related electric propulsion components are covered for 8 years or 100,000 miles, whichever comes first, starting from the original in‑service date, the day the truck was first sold or leased new.
- Coverage clock starts when the vehicle is first delivered to its original owner or lessee.
- Warranty follows the truck, not the driver, so it transfers to subsequent owners within the 8‑year/100,000‑mile window.
- Leased vehicles get the same 8‑year/100,000‑mile battery coverage as purchased ones.
- If the truck hits 100,000 miles before 8 years, the battery warranty ends at 100,000. If it hits 8 years first, mileage beyond that isn’t covered.
Don’t assume “new to you” means new warranty
What the Hummer EV Battery Warranty Actually Covers
GM’s Ultium warranty is written in corporate Esperanto, but the underlying idea is simple: if the high‑voltage system fails due to defects in materials or workmanship during the warranty period, GMC pays to fix it.
Key Components Typically Covered Under the Ultium Warranty
Exact language lives in the Warranty & Owner Assistance booklet in your glovebox, but these are the big-ticket items.
High‑voltage battery pack & modules
The Ultium pack beneath the Hummer EV’s floor, including individual battery modules and internal wiring, when they fail due to defects.
Drive units & inverter
Electric motors, inverters, and reduction gearboxes that turn battery power into wheel‑spinning torque.
High‑voltage & charging hardware
Onboard charger, high‑voltage cables, battery disconnects, contactors, and control electronics tied to propulsion.
In practice, this means if an Ultium module internally fails, a sensor goes bad inside the pack, or a factory‑installed high‑voltage cable was defective from day one, GMC covers parts and labor to repair or replace it at an authorized dealer, often by swapping one or more modules rather than the full pack.
Good news for owners
What Isn’t Covered: Battery Warranty Fine Print
Warranties are written by optimists and enforced by lawyers. With the Hummer EV, the exclusions are mostly common sense, but they’re worth knowing before you order your first lift kit or wade into saltwater like it’s an Instagram ad.
Common Reasons a Battery Claim May Be Denied
Damage from collisions or impacts
If the pack or high‑voltage system is damaged in a crash, curb hit, off‑road incident, or road debris strike, that’s an insurance claim, not a warranty repair.
Aftermarket modifications to high‑voltage systems
Non‑GM battery heaters, DIY performance tuners, or improperly installed accessories that tap into the high‑voltage system can void related coverage.
Neglect or improper maintenance
Ignoring warnings, continuing to drive with known HV faults, or not following recall instructions can give GMC cause to deny a claim.
Environmental and flood damage
Deep‑water immersion, severe corrosion from long‑term submersion, or fire damage generally fall outside warranty coverage.
Normal wear of non‑HV parts
Things like tires, brake pads, 12‑V battery, suspension bushings, and interior trim are not part of the high‑voltage warranty.
Water crossing reality check
Capacity Loss and Degradation: What to Expect
Every lithium‑ion pack loses capacity over time. The crucial question is whether GMC promises a minimum remaining capacity, for example, guaranteeing that the battery will retain at least a certain percentage of its original energy over the 8‑year term.
What GM guarantees
GM’s public materials emphasize that Hummer EV batteries are engineered for long life and warrant the pack against defects for 8 years/100,000 miles. But unlike some rivals, GM does not trumpet a specific percentage‑of‑capacity guarantee in broad marketing copy. The exact threshold, if defined, will be in the model‑year‑specific warranty booklet.
What owners typically see
Real‑world data on Hummer EV degradation is still early, but based on similar Ultium vehicles and modern liquid‑cooled packs, modest capacity loss over the first several years is normal, especially in hot climates or under heavy fast‑charging use.
Practical rule of thumb
Pickup vs. SUV and Model Years: Do Warranty Terms Change?
From a warranty standpoint, GMC does not treat the Hummer EV Pickup and Hummer EV SUV as different species. Both ride on Ultium hardware and, in the U.S., both carry the familiar 3‑year/36,000‑mile bumper‑to‑bumper, 5‑year/60,000‑mile powertrain and roadside assistance, and 8‑year/100,000‑mile battery/electric components coverage structure.
Typical Hummer EV Warranty Structure by Component
Always confirm exact coverage in the warranty booklet for your specific model year, trim, and region.
| Component | Typical Term | Mileage Limit | Notes |
|---|---|---|---|
| Bumper‑to‑bumper | 3 years | 36,000 miles | Most non‑wear items, paint, interior electronics. |
| Powertrain | 5 years | 60,000 miles | Electric motors, drive units; often aligned with roadside assistance. |
| High‑voltage battery & EV components | 8 years | 100,000 miles | Ultium pack, modules, and key propulsion electronics. |
| Corrosion (rust‑through) | 6 years | 100,000 miles | Covers sheet metal perforation from corrosion. |
| Roadside assistance | 5 years | 60,000 miles | Towing, lockout, jump‑starts; EV‑specific tow coverage may extend with battery warranty. |
Pickup and SUV share the same basic warranty architecture in the U.S.
Model‑year nuance
Battery Warranty for Second Owners and Used Hummer EVs
If you’re eyeing a used Hummer EV, sensible, given how colossal the sticker is when new, the good news is that GM’s battery warranty is typically fully transferable to subsequent owners within the 8‑year/100,000‑mile window.
- There’s usually no fee to transfer the Ultium battery warranty; it stays with the VIN.
- A 3‑year‑old Hummer EV with 35,000 miles will still have roughly 5 years and 65,000 miles of battery coverage left, assuming normal use.
- CPO (Certified Pre‑Owned) programs at GM dealers may layer additional coverage on top of the original warranty, worth asking about if you’re shopping at a franchise store.
- Private‑party buyers should verify warranty status by checking the in‑service date and mileage and, ideally, confirming with a GMC dealer.
How Recharged approaches used Hummer EVs
How GM Handles Battery Repairs and Replacements
When something goes wrong with a Hummer EV’s battery or high‑voltage system, the dealer doesn’t just shrug and order a whole new skateboard. The Ultium platform is modular for a reason: GM can often isolate and replace specific modules or components instead of the entire pack.
What a Typical Battery Warranty Visit Looks Like
Your experience can vary by dealer, but the broad steps are similar.
1. Diagnosis & scan
Technicians pull fault codes, inspect the high‑voltage system, and verify the concern, whether that’s reduced range, charging failures, or warnings.
2. Repair plan
GM engineering and the dealer determine whether they can replace modules, harnesses, or control electronics, or if the whole pack needs swapping.
3. Replacement & validation
Defective parts are replaced with new or remanufactured components, followed by software updates and test drives before the truck is returned.
Expect some down‑time
Protecting Your Hummer EV Battery, and Its Warranty
The Hummer EV’s Ultium pack is overbuilt for abuse, but it’s not invincible. A few simple habits will not only keep the battery healthier, they’ll also keep you firmly inside the lines of GMC’s warranty expectations.
Smart Habits to Preserve Battery Health and Coverage
Avoid chronic 0–100% fast charging
Use DC fast charging when you need it, but don’t live there. For daily use, charge on Level 2 and keep the pack roughly between 20–80% when convenient.
Let the truck manage its temperature
Don’t defeat or disable thermal management with aftermarket hacks. The cooling system is a big reason GM feels confident offering long battery warranties.
Follow software updates and recalls
If GM issues a software update or recall related to the battery, get it done promptly. Blowing off a safety recall can complicate future warranty claims.
Be smart off‑road
Protect the pack from big impacts. Rock strikes and high‑centered landings are hard on the underbody, and unlikely to be treated as gentle manufacturing defects.
Document unusual behavior
If range suddenly drops or the truck refuses to DC fast charge, note dates, mileage, and conditions. Detailed records make warranty conversations easier.
Buying a Used Hummer EV: How Recharged Helps
Shopping for a used Hummer EV is a bit like shopping for a used private jet: you absolutely want to know how the engines are doing. In this case, that’s the Ultium battery. A clean Carfax doesn’t tell you whether the pack has been abused, babied, or simply lived on the wrong side of Phoenix.
Battery health you can actually see
Every Hummer EV sold through Recharged includes a Recharged Score battery health report. We run dedicated diagnostics to surface pack state of health, charge behavior, and any high‑voltage fault history, so you’re not guessing about the most expensive part of the truck.
Full digital buying experience
From your sofa, you can get pre‑qualified for financing, value your trade, and have a Hummer EV delivered to your driveway, backed by our EV‑specialist support team and transparent pricing. If you’d rather kick the tires in person, you can visit our Experience Center in Richmond, VA.
Why this matters on a Hummer EV
GMC Hummer EV Battery Warranty FAQ
Frequently Asked Questions
Bottom Line on the Hummer EV Battery Warranty
Strip away the marketing gloss and the GMC Hummer EV’s battery warranty is pleasantly straightforward: 8 years or 100,000 miles of protection for the Ultium pack and electric propulsion hardware, transferable to future owners and backed by a modular repair strategy that rarely requires a full pack swap. The nuance lives in the usual places, how you use the truck, how you treat fast charging and off‑roading, and whether you stay current on software and recalls.
If you’re buying new, the warranty is a safety net for your early‑adopter ambitions. If you’re buying used, it’s a ticking clock you absolutely want to read correctly. That’s where tools like the Recharged Score battery health report, transparent pricing, and EV‑specialist guidance turn the Hummer EV from an anxiety machine into a truck you can enjoy, with the fine print already decoded.
