Batteries & power

Supplies energy to joints, sensors and computers. Cells store the energy; pack electronics monitor it and control charging and discharge.

Inside a battery pack

Cells store energy; interconnects, sensing and protection turn them into a managed pack. Open the layers to inspect each role.

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Inside a battery pack

Select a part to see its role.

Source & model scope

Illustrative cylindrical-cell pack. Cell count, interconnects and monitoring-board layout are schematic; the view does not define a voltage, series/parallel configuration or wiring plan. Original Korthos geometry.

Texas Instruments · mobile robot battery management · Model scope & reuse
Architecture, materials & specificationsArchitecture options, material requirements and integration constraints

Architecture options

Chemistry, cell format and pack servicing are separate decisions. Pack performance varies with load and temperature.

ApproachMechanismAdvantagesTrade-offs
LFP cellsLithium iron phosphate is used as the cathode material.Avoids nickel and cobalt in the cathode; generally offers good cycle life.Typically stores less energy per kilogram than high-energy nickel-based cells.
Nickel-based cellsCathodes such as NMC combine nickel with other metals.Can store more energy within a limited pack mass.Temperature, operating limits and protection remain critical; formulations differ.
Fixed packThe pack stays installed while charging.Avoids a frequently disconnected battery interface.Charging takes the robot out of service unless the operating setup allows otherwise.
Swappable packA depleted pack is exchanged for a charged one.Can shorten the interruption between work periods.Needs durable connectors, accessible mounting and a safe replacement procedure.

Specifications & operating limits

Watt-hours measure stored energy; watts measure the rate of use. Runtime is approximately usable energy divided by average power, with conversion losses and reserve included. Stored energy depends on both charge capacity and voltage.

Materials & constraints

Graphite-based anodes
Graphite stores lithium during charging. Some anodes include silicon to increase storage, but expansion and repeated cycling must be managed. Cell construction and operating limits determine how much capacity remains usable over time.
LFP or nickel-based cathodes
Lithium iron phosphate avoids nickel and cobalt; nickel-manganese-cobalt chemistries make different energy-density and thermal-management trade-offs. Pack construction, operating limits and protection also affect runtime, lifespan and safety.
Electrolyte & porous separator
Electrolyte transports lithium ions; the separator keeps the electrodes apart while allowing ion movement. Temperature and mechanical damage affect these layers; cell protection and pack structure are separate assembly requirements.
Copper, aluminium & pack structure
Current collectors and interconnects carry electrical current; the enclosure supports and protects cells. Conductors, cooling, protection electronics and housing all add mass beyond the cells themselves.

Dependencies & engineering limits

Cells & usable pack energy
In a series pack, one cell group can reach its discharge limit before the others. Balancing helps manage charge differences; it does not repair lost cell capacity.
Pack assembly & testing
Cell connections, temperature sensing and protection electronics form a coupled pack system. Connection resistance and protection settings matter alongside the cell’s advertised capacity.
Joint demand & voltage drop
Brief high-current movements can cause voltage drop and heating. Peak demand places different loads on the pack and power stage from average consumption.
Integrated actuators
Ageing & replacement
Usable capacity and power capability change with age and operating conditions. Pack access, mounting and connectors affect how easily a worn pack can be replaced.
Structure & materials

Manufacturing & assembly

Guide

About this route

The route shows one process or architecture. Select a step to see its function and connections; related parts can be parallel inputs or alternatives.

Function

Inputs & dependencies
Outputs & connections
Related processes & parts
Sources

Assembly · Representative route. Cell assembly plus a documented TI protection-board example.

Related parts & processes 5

Cells

Cells provide the pack’s underlying energy storage.

Cell chemistry and format are separate design choices.

Sources & technical scope

Illustrative images of generic materials and components.

Related references
Link to this detail

Production equipment

Market context

Battery active materials

Cathode active material production
About 85%China · global production share
Anode active material production
Over 90%China · global production share

Global processing shares for materials used in electric-car batteries.

CATL battery market position

39.2%Global EV battery usage
30.4%Global energy-storage shipments

EV battery usage and energy-storage shipments are separate markets. Both figures cover global supply in 2025.

Unitree

US$500BT2-05 · retail pack price

BT2-05 retail pack price in USD; industrial volume pricing and cell supplier are undisclosed.

LFP chemistry & production

ChinaNear-exclusive LFP supply · estimate

LFP removes nickel and cobalt from the cathode, but manufacturing remains concentrated.

Supply constraints

Battery-grade refining adds dependencies

LFP requires purified phosphoric acid; LMFP and other manganese-bearing cathodes also depend on battery-grade manganese sulphate. The IEA’s 2025 assessment places China at 75% of global purified phosphoric acid supply and 95% of battery-grade manganese sulphate supply.

Sodium-ion substitution has production limits

Sodium-ion removes lithium, but commonly uses hard-carbon anodes whose processing can raise costs. Stanford/SLAC finds that production scale alone does not ensure a price advantage over LFP: energy density and mineral prices also matter.