Lesson 1Battery repair process workflow: isolation, safe disassembly, cell verification, balancing, reassembly, and test cycleFollow a structured, safe workflow for battery repair. Practice isolation, opening packs, inspecting welds and insulation, replacing cells, rebalancing, resealing, and running post-repair test cycles before returning scooters.
Isolation, PPE, and workbench preparationOpening packs without causing new damageCell replacement, welding, and insulationFinal balancing, sealing, and test ridesLesson 2Cell-level diagnostics: IR measurement, capacity estimation using simple timed load test, and spotting cell imbalancesDive into cell-level testing techniques. Measure internal resistance, estimate capacity with timed load tests, identify imbalanced parallel groups, and decide which cells are recoverable versus unsafe or uneconomical.
Using ESR meters and four-wire techniquesTimed discharge tests for capacity estimatesFinding weak cells within parallel groupsCriteria for rejecting marginal cellsLesson 3BMS and firmware checks: extracting BMS logs/telemetry where possible, common BMS failure symptoms, and firmware reset/firmware update considerationsLearn to access and interpret BMS data when available. Review fault logs, cycle counts, temperature history, firmware versions, and decide when resets or updates are safe or hardware replacement wiser.
Connecting to BMS apps, tools, or adaptersReading fault codes, flags, and event logsEvaluating cycle count and SOH indicatorsFirmware reset and update risk assessmentLesson 4Li-ion battery fundamentals: cell chemistry, nominal voltages, capacity (Ah), internal resistance, and state-of-charge estimationUnderstand Li-ion cell structure, common chemistries, and how voltage, capacity, internal resistance interact. Learn how these affect range, power, aging, and state of charge estimation in the workshop.
Common scooter chemistries: NMC, LFP, NCANominal, max, and cutoff voltage per cellCapacity (Ah) vs. energy (Wh) vs. C-rateInternal resistance and its measurement basicsLesson 5When to replace pack vs. repair cells: economic, safety, and longevity criteria; pros and cons of cell replacement vs. full pack replacementLearn to decide between full pack replacement and cell-level repair. Compare cost, safety margins, expected lifespan, labour time, liability to recommend options protecting rider and business.
Cost comparison: parts, labor, and shop overheadRisk assessment: fire, recalls, and liabilityEstimating remaining useful life of old packsWhen to refuse repair and recommend new packLesson 6Interpreting symptoms: sudden shutdown at 40–50% and reduced range — common failure modes (capacity loss, increased internal resistance, BMS cutoff, cell group failure)Link real-world symptoms to likely battery faults. Analyse sudden shutdowns, reduced range, weak acceleration, inconsistent gauge readings to distinguish capacity loss, high resistance, BMS cutoffs, cell group failures.
Patterns of range loss and voltage sagSudden cutoff at mid SOC and BMS triggersDiagnosing weak cell groups in series stringsDifferentiating pack vs. controller issuesLesson 7Battery management system (BMS) role: balancing, over/under-voltage protection, current limiting, and telemetry interfacesExplore how the BMS protects the pack and rider. Study balancing methods, over and under voltage cutoffs, current limiting, temperature sensing, telemetry data exposed to controllers or diagnostic tools.
Passive vs. active cell balancing methodsOver/under-voltage and current protectionsTemperature sensing and thermal deratingBMS data lines: CAN, UART, and proprietaryLesson 8Preliminary non-invasive checks: open-circuit voltage, resting voltage distribution, and pack voltage vs. expected valuesPerform quick, non-invasive tests before opening a pack. Measure open-circuit voltage, compare to rated specs, check resting voltage drift, decide on deeper diagnostics or immediate replacement.
Measuring pack open-circuit voltage safelyComparing measured voltage to nameplate dataMonitoring resting voltage over several hoursRed flags that justify deeper investigationLesson 9Under-load and charging checks: voltage sag under load, charge acceptance, charger output verification, and charge port/connector inspectionLearn to test a battery safely under load and during charging. Measure voltage sag, verify charger output, check charge acceptance, inspect connectors and ports for heat, corrosion, or damage.
Simulating real-world load with test equipmentMeasuring and interpreting voltage sagVerifying charger voltage and current outputInspecting charge ports, pins, and wiringLesson 10Battery safety and customer communication: explaining thermal runaway risk, storage/charging guidance, safe transport, and warranty/legal disclaimersDevelop safe handling habits and clear customer communication. Explain thermal runaway risks, storage and charging rules, transport precautions, document disclaimers, waivers, warranty limitations.
Recognizing and handling high-risk batteriesSafe charging, storage, and transport guidanceCustomer education scripts and checklistsDocumenting waivers and repair limitations
