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, replacing cells, rebalancing, resealing, and test cycles before returning scooters to customers.
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. Measure internal resistance, estimate capacity with timed load tests, identify imbalances, and decide which cells are recoverable or unsafe for continued use.
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 BMS data. Review fault logs, cycle counts, temperature history, firmware versions, and decide on safe resets, updates, or hardware replacement.
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, chemistries, voltage, capacity, resistance interactions. Learn how these affect range, power, aging, and state of charge estimation in workshops.
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 replacementDecide between pack replacement and cell repair. Compare cost, safety, lifespan, labour, liability to recommend options protecting riders and business in Botswana.
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 symptoms to battery faults. Analyse shutdowns, reduced range, weak acceleration, gauge issues to distinguish capacity loss, resistance, BMS cutoffs, cell 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 BMS protection. Study balancing, voltage cutoffs, current limiting, temperature sensing, telemetry for 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. Measure open-circuit voltage, compare specs, check voltage drift, decide on deeper diagnostics or 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 inspectionTest battery under load and charging. Measure voltage sag, verify charger, check acceptance, inspect ports for heat, corrosion, 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 habits and communication. Explain thermal runaway, storage/charging rules, transport, document disclaimers, waivers, warranty limits.
Recognizing and handling high-risk batteriesSafe charging, storage, and transport guidanceCustomer education scripts and checklistsDocumenting waivers and repair limitations
