What is inside a battery pack?
Back on the driveway. The app shows the battery at 80%, about 56 of 70 kWh. Outside it is minus 3 °C.
The car warmed the battery during the last hour of charging, because the departure time was set the evening before.
The questionWhat actually stores those 56 kWh, and who decides how warm the battery should be?
Guess firstMore than half of all electric car batteries deployed worldwide in 2025 used one chemistry that contains no cobalt. Which one?RevealHide
Lithium iron phosphate, LFP: over 55% of EV batteries deployed globally in 2025, up from nearly 50% in 2024.
The smallest unit. When it charges, lithium ions move from one electrode to the other; when it discharges, they move back and drive a current.
Select each level to see what it adds.
Most electric cars use one of two lithium-ion families:
- , nickel manganese cobalt, stores more energy per kilogram.
- , lithium iron phosphate, contains no cobalt and costs less. In 2025, LFP packs were on average more than 40% cheaper per kWh than NMC packs, partly because the average includes stationary storage, which mostly uses LFP and needs less energy density.
LFP has the lower energy density, so for the same energy it needs more space. The choice is a trade-off between range per kilogram and cost.
The pack is built from cells, either grouped in modules or, as cell-to-pack, without them; it sits in the floor between the axles, and a watches the cells.
close to this on average for a new battery electric car
more than this share of EV batteries deployed globally
more than this share of EV battery demand in the EU
average change in 2025, across EV and storage batteries
All figures for 2025 from the IEA Global EV Outlook 2026.
Why the battery likes it mild
Lithium-ion cells work best in a moderate temperature range, which ADAC gives as about 10 to 40 °C. Thermal management keeps the cells from overheating, and in the cold it warms them and limits the power.
That is why the car warmed its battery before departure: a warm battery accepts and fast charging sooner. How the BMS shapes charging power is shown in the charging curve.
Check your understanding
3 questions. Answer all of them to complete this stop. Each answer explains itself.
What is the main trade-off between LFP and NMC cells?
Both chemistries charge with AC and DC and appear in cars. The difference is energy per kilogram against cost and materials.
What does the battery management system do?
Converting current for the motor is the inverter's job, the subject of stop 03. The BMS protects the cells.
Why did the car warm its battery before departure?
Cold slows the chemistry, so the BMS limits power. Warming the pack while still plugged in uses grid energy instead of the battery's own.
- BMS Battery management system: the car's electronics that decide how much power the battery accepts at each moment. EV charging fundamentals, stop 04 Glossary
- LFP Lithium iron phosphate: a lithium-ion chemistry without cobalt, lower in cost, with less energy per kilogram than NMC. Glossary
- NMC Nickel manganese cobalt: a lithium-ion chemistry that stores more energy per kilogram than LFP. Glossary
- Regenerative braking Slowing down with the motor working as a generator, which returns part of the car's energy of motion or height to the battery. Stop 05 Glossary
- IEA: Global EV Outlook 2026: Electric vehicle batteries. https://www.iea.org/reports/global-ev-outlook-2026/electric-vehicle-batteries. Checked 09 Oct 2026. Licence: CC BY 4.0.
- ADAC: Glossar Elektromobilität: battery management system, cell-to-pack, DC/DC converter, inverter, onboard charger, state of health, motor types. https://www.adac.de/rund-ums-fahrzeug/elektromobilitaet/elektroauto/glossar-elektromobilitaet/. Checked 13 Oct 2026.
- ADAC: Glossar Elektromobilität: battery management system, cell-to-pack, DC/DC converter, inverter, onboard charger, state of health, motor types. https://www.adac.de/rund-ums-fahrzeug/elektromobilitaet/elektroauto/glossar-elektromobilitaet/. Checked 13 Oct 2026.
- ADAC: Elektroantrieb und Elektromotor, Aufbau und Funktion (2 October 2023): components, torque, one gear, efficiency, battery temperature, gross and net capacity. https://www.adac.de/verkehr/tanken-kraftstoff-antrieb/alternative-antriebe/elektroantrieb/. Checked 13 Oct 2026.
- IEA: Global EV Outlook 2026: Electric vehicle batteries. https://www.iea.org/reports/global-ev-outlook-2026/electric-vehicle-batteries. Checked 09 Oct 2026. Licence: CC BY 4.0.
- ADAC: Elektroantrieb und Elektromotor, Aufbau und Funktion (2 October 2023): components, torque, one gear, efficiency, battery temperature, gross and net capacity. https://www.adac.de/verkehr/tanken-kraftstoff-antrieb/alternative-antriebe/elektroantrieb/. Checked 13 Oct 2026.