Technical Library
Battery engineering library.
Choose a topic or start with an engineering task. Follow the requirements, understand the battery response and define the measurements that support the decision.
Start with an engineering task
Battery drops out under load?
Follow the voltage path from the measured loss to the equipment load.
Requirements & sizing
Define the equipment load, mission energy and charging architecture.
What Information Is Required to Engineer a Custom Battery?
A usable brief connects the equipment mission to electrical, mechanical, charging, validation and production decisions. Unknowns need an owner and a resolution method.
Specify a Robot Battery From Its Duty Cycle
Turn the mission into voltage, power, time and environmental requirements before choosing amp-hours or chemistry.
Your Motors Add Up to 200 A Stall. What Battery Rating Do You Actually Need?
Motor stall current describes one motor condition. A battery requirement must describe what the controllers draw, for how long, and how the system clears a blocked motor.
Can Your Equipment Run While the Battery Is Charging?
The answer comes from the power-path architecture, source limits and load transients. Start by identifying where current is measured and controlled.
Electrical behavior
Understand voltage sag and locate losses in the battery system.
Why Battery Voltage Sags Under Load
Terminal voltage falls under load because ohmic loss, electrochemical polarization and transport effects act across different timescales.
Your Battery Sags Under Load. Where Is the Voltage Lost?
Separate cell behavior from losses in joints, switches and cables using synchronized measurements at defined electrical boundaries.
Internal Resistance Is Not One Resistance
A battery resistance value is meaningful only when its excitation, timing, operating condition and calculation are defined.
BMS & protection
Coordinate sensing, current limits, precharge and the power path.
What Should the BMS Measure and Control?
A BMS is a measurement, protection and control system. Its architecture follows the battery voltage, current path, isolation boundary, charger and equipment interface.
A “200 A BMS” Does Not Make a 200 A Battery
The battery current passes through cells, joints, switches and connectors. The monitoring circuit and its protection settings cover only part of that system.
Precharge, Contactors and Fuses: Coordinate the Whole Power Path
A capacitive load, normal switching and fault interruption place different demands on the battery power circuit. Assign each function to a rated component.
Mechanical & thermal design
Resolve the enclosure, heat flow and temperature measurement.
What Makes a Battery Enclosure Mechanically Buildable?
The enclosure must locate cells, carry loads, protect insulation, transfer heat and remain assemblable across tolerance and service conditions.
How Should a Battery Pack Handle Heat?
Thermal design starts with losses and service conditions, then establishes a continuous path from each heat source to the environment.
Where Should Battery Temperature Be Measured?
A convenient sensor location can miss the limiting cell, joint or switching device. Sensor placement follows the expected heat sources and thermal paths.
Testing & measurement
Verify cell performance with reproducible measurements and acceptance criteria.
Why a Cell Can Pass a Capacity Test and Still Fail Your High-Power Application
A capacity result describes delivered charge under one test condition. Your equipment also needs loaded voltage, usable energy and thermal margin throughout its duty cycle.
DCIR vs AC Impedance vs ESR
DCIR, AC impedance and ESR can all be reported in milliohms, but the shared unit does not make the measurements interchangeable.
How to Measure DCIR Correctly
A valid DCIR result is a reproducible current-step response with defined preparation, sensing, timing and calculation.
Why DCIR Depends on Pulse Duration
Calculated DCIR changes with pulse duration because terminal voltage continues to evolve after the current step.
What Is HPPC?
Hybrid Pulse Power Characterization maps discharge and regenerative pulse capability across the battery operating window.
Cell Matching: What Actually Needs to Match?
A common model number and a “Grade A” description leave the pack acceptance limits undefined. Match the measurements that affect the application.
Production & qualification
Define applicable standards, repeatable processes and batch records.
Which Battery Standards and Certifications Apply to Your Product?
Start with the application, market and object being assessed: cell, battery, equipment or installed system. Each has a different evidence boundary.
The Prototype Worked. Can Production Repeat It?
A successful prototype validates one build under tested conditions. Production readiness requires control of variation, configuration and the tests that release every batch.
What Production Data Should Accompany a Battery Batch?
A pass/fail summary is useful only when you can identify what was built, how it was checked and which configuration was released.
Tools & supporting references
Bring the open decision into engineering review.
Collect the load profile, interface limits and available evidence. Build a brief with the unresolved questions attached.
Build the review requirement