EV & Hybrid Battery Chemistry & Glossary

Every electrified vehicle in the US market runs one of four cell chemistry families. Each ages differently, costs differently, and tolerates fast charging and cold weather differently. This page is a working primer; the pack reference table is where the per-vehicle hardware lives.

Phase 1 stub. Section narratives are placeholders pending a full editorial pass. The glossary below is current.

NCM — Nickel-Cobalt-Manganese

The dominant chemistry for long-range US EVs. Variants like NCM 811 (80% nickel) push energy density at the cost of cycle life and thermal headroom. Hyundai e-GMP, Ford Mach-E ER, GM Ultium, BMW Gen5, and Tesla Long Range trims all run NCM-family cells.

Full editorial coverage coming soon. See the pack reference table for current packs using this chemistry.

NCA — Nickel-Cobalt-Aluminum

Tesla's long-running pack chemistry, supplied by Panasonic at Gigafactory Nevada. High energy density, well-characterized degradation curve, and a long field history. Mostly seen in Tesla 2170 packs.

Full editorial coverage coming soon. See the pack reference table for current packs using this chemistry.

LFP — Lithium-Iron-Phosphate

Cobalt-free, longer cycle life, lower energy density, cheaper to make. Tesla Model 3 RWD shifted to LFP in 2021; Ford F-150 Lightning Standard Range, Rivian R1T Standard, and most Chinese-built EVs ship LFP packs. Cold-weather performance is the trade-off.

Full editorial coverage coming soon. See the pack reference table for current packs using this chemistry.

NiMH — Nickel-Metal Hydride

The pre-2023 Toyota hybrid pack chemistry. Air-cooled, low energy density, decade-plus field life when treated well. Replaced by Li-ion (NCM) starting with Toyota Hybrid Gen5 in 2023.

Full editorial coverage coming soon.

Glossary

BMS: Battery Management System. Firmware + sensors that monitor cell voltage, temperature, and state of charge; balances cells and protects the pack.
ICCU: Integrated Charging Control Unit. Used by Hyundai/Kia e-GMP packs; combines onboard charger and DC-DC converter. Subject of recall 24V-244 and follow-ups.
Prismatic: Cell format: rectangular hard-shell cells stacked in a frame. Used by LFP packs (Tesla, BYD) and Hyundai e-GMP. Higher pack-level efficiency than cylindrical.
Pouch: Cell format: soft-shell laminated cells. Used by LG NCM packs in Mach-E, Ultium, and Hyundai e-GMP. Energy-dense but susceptible to swelling under heat stress.
Cylindrical: Cell format: tall round cans (18650, 2170, 4680). Tesla's primary format. Modular and well-suited to high-volume manufacturing; module-pack ratio is lower than prismatic.
V2L: Vehicle-to-Load. The vehicle's battery acts as a power source for external devices via a household-style outlet (typically 1.6-3.6 kW). Hyundai/Kia, Ford F-150 Lightning, Rivian R1T support it.
V2H: Vehicle-to-Home. The vehicle powers a home through a bidirectional charger during outages. Currently mostly Ford F-150 Lightning + Sunrun integration; Hyundai/Kia partial.
Heat pump: HVAC system that uses a refrigerant cycle (instead of resistive heaters) to warm the cabin and battery in cold weather. Materially extends real-world winter range.
Regen: Regenerative braking. The motor acts as a generator during deceleration, returning energy to the pack. One-pedal driving and B-mode are stronger regen settings.
DC fast charge: Direct-current high-power charging that bypasses the onboard charger. Public stations operate at 50-350 kW. Different packs have different peak rates (the Hyundai e-GMP 77.4 hits 233 kW; older Bolt EV peaks ~55 kW).
Onboard charger: AC charger built into the vehicle that converts wall AC to DC for the pack. Sized 7.2 kW (single phase), 11 kW (three-phase 16A), or 22 kW (three-phase 32A).
800V architecture: Pack and high-voltage system designed for ~800 volts (vs. the more common 400V). Enables higher peak DC charge rates with lower current. Hyundai e-GMP, Porsche Taycan, Audi e-tron GT, Lucid Air.
Capacity floor: The percentage of original battery capacity below which the manufacturer covers replacement under warranty. Most US EVs: 70%. Hyundai/Kia: 70%. Some older Nissan Leafs: 66.25%.
Aggregate degradation: Average percentage capacity loss across a fleet sample, typically reported by Recurrent or Geotab. Not a guarantee for any individual vehicle — climate and charging behavior shift the curve significantly.
Thermal management: How the pack regulates temperature. Liquid (glycol loop) is most common on EVs; air-cooled is typical on hybrid packs and the Nissan Leaf.
Thermal runaway: A self-propagating thermal failure in a damaged or defective cell. Triggers fire risk. NHTSA fire-event recalls (Bolt EV, Hyundai Kona EV, certain VW MEB packs) all involved thermal-runaway concerns.
State of Charge: SOC. The current pack charge level expressed as a percentage of total capacity. Different from the user-displayed gauge, which often hides the bottom 5-10% as a buffer.
State of Health: SOH. The estimated current pack capacity as a percentage of original capacity. Reported by some manufacturer tools and aftermarket OBD-II scanners.
Pack architecture: How cells are organized into modules and how modules are organized into the pack. Module-based packs (most current EVs) allow individual module replacement; cell-to-pack designs (Tesla 4680, BYD Blade) integrate cells directly into the structure.
Cell supplier: The company that manufactures the cells, distinct from the OEM. Most NCM cells in the US market come from LG Energy Solution, Panasonic, SK On, or Samsung SDI. LFP cells largely from CATL or BYD.

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