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    Energy on the go

    Energy 4 h 20 slides

    Never run out of charge

    Learning objectives

    By the end of this module you'll be able to:

    • Calculate your real daily energy budget (Wh/day = Σ P × H) and size it with the ×3 rule.
    • Convert a power bank's capacity into real Wh and anticipate IATA restrictions when flying.
    • Estimate the real output of a portable panel (Wp × PSH × efficiency) against the manufacturer's specs.
    • Choose between MPPT and PWM and put a figure on the production gain for your installed power.
    • Look after your lithium batteries: the 50% rule, no charging below 0°C, the safety of the ANL fuse.
    • Pick the energy kit that fits your nomad profile (hiking, bikepacking, van, motorbike, sailboat).

    Slide 1 of 20

    Energy audit

    Mapping your electrical needs on the road

    Before choosing any gear — calculate your real consumption by profile

    DevicePowerUse/dayWh/dayTypical profile
    Smartphone (full charge)10 W1.5 h15 WhEveryone
    Laptop 13-15"45-65 W4-6 h200-390 WhDigital nomad, van
    Drone (4S battery charge)80 W1 h80 WhContent creator
    LED lighting tent/van5-15 W4 h20-60 WhCamper, van lifer
    12V compressor fridge 40L45 W avg.24 h480-650 WhVan, boat
    12V water pump30 W0.2 h6 WhVan, boat
    CPAP (sleep apnoea)30-40 W8 h240-320 WhMedical nomad
    Action camera + charger8 W1 h8 WhAthlete, hiker

    Total daily energy budget

    Wh/day = Σ (P_device × H_use)

    Ex.Light hiker: 15 + 390 + 8 = 413 Wh/day → a 26,800 mAh (96 Wh) power bank covers 1/4 of a day → you need a 25-40 Wp portable solar panel

    The ×3 rule: size your system for 3 times your minimum needs. Bad weather, charging inefficiency, conversion losses — in the real world you get 30-40% less than the specs.

    Slide 2 of 20

    Power banks

    Expedition power banks — what really matters

    Not all mAh are equal — understanding real energy density

    Real energy of a power bank

    Wh = mAh × Nominal voltage (3.7V) / 1000

    mAh × 3.7V=Internal rated capacity (Li-ion 18650 or LFP cells)

    Efficiency 85-90%=DC-DC conversion losses while recharging the device

    Ex.26,800 mAh power bank: 26,800 × 3.7 / 1000 = 99.2 real Wh. 88% efficiency → 87 usable Wh → charges a 65 W laptop for 1h20
    Power bankCapacityReal WhWeightMax output powerSolar charging
    Anker 737 (PowerCore 24K)24,000 mAh88 Wh680 g140 W (USB-C PD)Yes, via USB-C
    Anker SOLIX C300Best all-rounder290 Wh290 Wh3.8 kg300 W AC + DCBuilt-in MPPT
    Jackery Explorer 300 Plus288 Wh288 Wh3.75 kg300 W ACBuilt-in MPPT
    EcoFlow RIVER 2256 Wh256 Wh3.5 kg600 W (X-Boost)Built-in MPPT
    Goal Zero Sherpa 100 AC94 Wh94 Wh965 g100 W ACMPPT via port

    Power banks > 100 Wh are restricted in aircraft cabins (IATA): above 160 Wh, they are banned from cabin baggage. In the hold: every Li-ion format is banned. Plan accordingly for long-haul trips.

    Knowledge check

    What is the real energy of a 26,800 mAh power bank (3.7 V cells)?

    Slide 3 of 20

    Portable panels

    Portable solar panels — flexible, rigid, folding

    The right panel for the right use — real field performance

    TypeEfficiencyWeight/WpDurabilityBest for
    Folding monocrystalline (Anker, Jackery)Recommended21-23%70-100 g/WpGood (ETFE)Long hikes, bikepacking, van
    Flexible monocrystalline (glued)18-21%40-60 g/WpAverage (delamination)Van/motorbike roofs, curved surfaces
    Solar backpack (25 Wp)16-18%50 g/Wp (fabric)GoodShort hikes, trickle-charging a smartphone
    Rigid (crystalline silicon)22-24%600-900 g/WpExcellent (25 years)Fixed base, full-time van, boat

    Real daily output of a portable panel

    Wh/day = Wp × PSH × η_system × f_angle

    PSH=Peak sun hours by zone and season (2-6h)

    η_system=System efficiency (0.75-0.85 with MPPT)

    f_angle=Tilt/orientation factor (0.7-1.0)

    Ex.100 Wp panel, summer in France (PSH 5h), MPPT, optimal orientation: 100 × 5 × 0.80 × 0.95 = 380 Wh/day → a full charge for a laptop + smartphone + drone

    The full-sun efficiency myth: efficiency specs are measured at 25°C, 1,000 W/m², perpendicular to the sun. In real nomad use (sub-optimal position, hot cells), count on 65-75% of the manufacturer's specs.

    The rest of the module is waiting for you

    17 more slides, quizzes and a badge to earn.

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