Power, Fuel, and Batteries

Lesson Overview

A modern team carries its capability in its kit, and most of that kit runs on stored energy. The radio that lets a section talk, the light that lets it work after dark, the device that holds the map, the team's TAK end-user device and its Meshtastic nodes that share a common picture, all of them draw on batteries, and when the battery is flat the capability is gone. Beyond the small stuff, the vehicles that move the team, the generator that powers a base or a clinic, and the stove that heats the meal all run on fuel, and fuel is a commodity that must be planned, stored, and handled with care because it is dangerous when it is not. This lesson treats power as what it is: a commodity to be planned by consumption like water and rations, not a thing that simply happens when a switch is thrown.

The discipline at the heart of the lesson is simple to state and easy to neglect. A flat battery is a logistics failure, not bad luck. A radio that dies mid-task did not fail; it was not planned for, not given spares, not charged. The planner who treats power seriously asks, for every device the team carries, how long its battery lasts, how many it will need in a day, how many spares to carry, and how those batteries will be charged or replaced before the team runs out. The same discipline applies to fuel: how much the vehicles, generator, and stoves will burn, where it is stored safely, and how it is handled without harm. Power planning is the difference between a team that stays in contact, lit, mapped, moving, and fed, and one that quietly goes dark.

This is the knowledge layer. The hands-on stores work of this commodity class, signing for batteries and fuel, stocktaking them, and storekeeping them safely, is practised and signed off in person where supervision allows, and the fuelling of vehicles, the safe running of a generator, and the use of stoves are practical skills certified in person under supervision. By the end you will be able to plan batteries by device and by day and build a charging plan from mains, vehicle, or solar power, explain why a flat battery is a logistics failure that ties directly to SIG communications, plan fuel for vehicles, generators, and stoves by consumption, state the rules for storing and handling fuel safely, and bring all of it together as the power plan for a team on a task.

Key Terms

• Battery life: how long a given battery powers a given device before it is flat, the figure all battery planning is built from; it varies with the device, the load, the cold, and the age of the battery.
• Spares: charged batteries carried in reserve so that a device whose battery dies can keep working at once, planned per device and not as an afterthought.
• Charging plan: the deliberate arrangement for keeping batteries charged on a task, drawing on mains, vehicle, or solar power, so that flat batteries are recharged before they are needed again.
• Rechargeable battery: a battery that can be charged and used many times, planned around a charging source; lighter on resupply but dependent on power to charge.
• Primary (single-use) battery: a battery used once and replaced, planned around a stock of spares; simple and reliable but consumed steadily and demanded like any other store.
• Mains power: electricity from a fixed supply at a base or building, the simplest charging source when it is available.
• Vehicle power: electricity drawn from a vehicle, used to charge devices and batteries when mains is not available, within the vehicle's own limits.
• Solar power: electricity from a portable solar panel, a charging source that needs no fuel and no fixed supply, useful where neither mains nor a vehicle is at hand.
• Generator: a fuel-powered machine that produces electricity, used to power or charge a base, a clinic, or a charging point where mains is absent.
• Fuel: the liquid or gas that powers vehicles, generators, and stoves; a planned, accounted, and carefully handled commodity that is dangerous when mishandled.
• Consumption rate: how much of a commodity, a battery or a litre of fuel, a device or machine uses in a set time, the figure all this planning is built from.

Power is a commodity, not a given

It is easy to treat power as something that is simply there. The radio works, the light comes on, the device shows the map, and the energy that makes all of that happen is invisible until the moment it runs out. That moment is the whole subject of this lesson. Stored energy, in a battery or a fuel can, is a commodity exactly as water and rations are: it is held in a known quantity, it is consumed at a rate, and it runs out if it is not replenished before the team needs it. The planner who understands that plans power; the one who does not discovers it is gone at the worst time, which on a task is usually the moment the capability matters most.

The governing idea of the lesson follows from that. A flat battery is a logistics failure, not bad luck. When a section's radio dies on task, it is tempting to call it misfortune, but it is nothing of the sort. The battery had a known life. The task had a known length. Spares could have been carried and a charging plan could have been made, and if they were not, the failure was planned in from the start by the person who did not plan the power. This is not a hard discipline to keep; it is only one that is easy to skip, because power is invisible until it fails. The remedy is to make it visible: to write down every device the team carries, what it draws, how long it lasts, and how it will be kept alive, and to treat that plan as seriously as the water plan, because a team that has gone dark, lost contact, lost its light, lost its map, is as surely out of action as one that has run out of water.

Batteries first: plan by device and by day

Batteries are planned the same way every commodity in this course is planned, but with one extra column: not just people and days, but devices. The unit of battery planning is the device, because each device has its own battery, its own appetite, and its own consequence when it dies. So the planner lists the devices the team will carry, and for each one answers a short set of questions. How long does its battery last in use? How many battery-changes will a day of the task demand? How many spare batteries should be carried so that a dead one is replaced at once? And how will those batteries be charged or replaced over the length of the task?

Take the team's main devices in turn. The radio is first, because of every device it is the one whose failure is felt soonest and worst, and it is treated in its own right below. Then the lights that let the team work, move, and stay safe after dark, which are needed every night and which a planner must never assume will simply last. Then the devices that hold the picture: the smartphone or tablet that carries the map and the notes, the team's TAK end-user device that shares a common operating picture, and the Meshtastic nodes that carry text and position across the team over their own low-power mesh. Each of these has a battery life that the planner must know rather than guess, because the cold shortens it, age shortens it, and a screen left bright drains it fast. For each, the planner sets a realistic life, works out how many spares a day demands, and folds the answer into the plan.

The table below shows the shape of a battery plan. The planner fills one line per device, sets the life honestly for the conditions, and reads off the spares and the charging need. The figures shown are illustrative, to be replaced with the real ones for the actual kit and weather, and the rule beneath the table is the one that matters: carry spares, and have a way to charge.

  BATTERY AND POWER PLANNING TABLE  (one line per device)

  Device            Battery   Hrs of use   Days   Spares to    Charge
                    life      per day      on     carry        from
                    (in use)               task   (per device)
  ----------------  --------  -----------  -----  -----------  ----------
  Radio (per set)   ~8 hrs    ~12 hrs/day  3      2 charged    mains/veh/
                                                  + on charge  solar
  Head torch /       ~6 hrs    ~4 hrs/night 3      1 to 2       spares or
   work light                                                  recharge
  Phone / tablet     ~8 hrs    most of day  3      power bank   mains/veh/
   (map, notes)                                    + charge     solar
  TAK end-user       ~6 hrs    most of day  3      1 + on       mains/veh/
   device                                          charge       solar
  Meshtastic node    ~24 hrs+  continuous   3      1 + small    solar/USB
                     (low power)                   panel        trickle

  ----------------------------------------------------------------------
  RULES:
   - Plan a REALISTIC battery life: cold and age make it SHORTER.
   - Carry SPARES per device, charged, ready to swap in at once.
   - Have a CHARGING PLAN before the task, not a hope.
   - A flat battery is a LOGISTICS FAILURE, not bad luck.

The charging plan: mains, vehicle, or solar

Carrying spares answers the question only for so long. On any task longer than the batteries themselves will last, the spares must be put back into service, which means they must be charged, and charging needs a source of power. So a battery plan is only half done until it has a charging plan beside it, naming where the power to recharge will come from. There are three sources a small team can usually draw on, and a good plan often uses more than one so that the loss of any single source does not leave the team in the dark.

The first source is mains power, the fixed electrical supply at a base, a building, or any place with a working socket. It is the simplest source when it is there: plug in the chargers and the batteries come back to life with no fuel and no fuss. The planner's job is to know whether mains will be available, where, and when, and to carry the chargers and leads to use it. The second source is vehicle power, the electricity a vehicle can give up through its own outlets to charge devices and batteries when no mains is at hand. It is widely useful because the team's vehicles travel with it, but it has limits: a vehicle's power is not unlimited, and draining it carelessly to charge a stack of devices can leave the vehicle itself unable to start, which is a worse failure than a flat radio. So vehicle charging is planned within sensible limits and not relied on to do everything.

The third source is solar power, a portable solar panel that turns daylight into charge with no fuel and no fixed supply. Its great value is independence: a team far from mains and rationing its vehicle can still keep small devices and low-power nodes alive from the sun, and the Meshtastic nodes in particular, sipping power as they do, suit solar trickle-charging well. Its limit is equally plain: it needs daylight and good weather, and it charges slowly, so it supplements a plan rather than carrying it alone. The sound charging plan therefore layers the sources: mains when at a base, vehicle on the move within limits, and solar as the independent backstop, so that the team's power does not rest on any single point that, lost, takes the whole team dark.

  CHARGING SOURCES  (layer them; do not rely on one)

  Source     Good for                  Watch out for
  ---------  ------------------------   ------------------------------
  MAINS      fast, fuel-free charging   only where a supply exists;
             at a base or building      carry the right chargers/leads

  VEHICLE    charging on the move,      LIMITED power; do not flatten
             always travels with team   the vehicle's own battery

  SOLAR      independent, no fuel,      needs daylight + good weather;
             suits low-power nodes      charges SLOWLY; a supplement

  GENERATOR  powering a base / clinic   burns FUEL (plan it); a noisy,
             and bulk charging          hot machine, handle with care

  PLAN: name the source for EACH device, and a fallback for each.

Batteries and communications: the SIG link

Of every device on the battery plan, the radio sits first for a reason that reaches beyond logistics into the team's ability to function at all. Communications hold a team together. A section that can talk can be controlled, can report, can call for help and be helped; a section that has gone silent is on its own, and on a relief task a silent team cannot be coordinated with the people it serves or the headquarters that supports it. All of that capability runs on the radio's battery, and so the single most important line on the battery plan is the radio's. This is where logistics and signals meet, and it is why this lesson ties directly to the SIG communications training.

The discipline the two share is the spare battery and the charging routine. SIG teaches the operator to manage the radio's power: to start the task with a fresh battery, to carry charged spares, to change a battery before it dies rather than after, and to keep the charging routine going whenever a source is available. LOG plans the means for all of that: the right number of spares demanded and carried, and a charging plan that names where the radio's batteries will come back to life. Neither half works without the other. The best charging plan is wasted if the operator does not change the battery in time, and the most disciplined operator is helpless if no spares were planned or no charging source provided. So the radio's power is planned by the logistician and managed by the signaller together, and between them they keep the team in contact. A radio that goes flat on task has failed both of them, and "the battery died" is never an excuse; it is the symptom of a plan that was not made or not kept.

Fuel: planning by consumption

When the energy needed is more than a battery can hold, the team turns to fuel: the petrol or diesel that runs the vehicles, the fuel that drives a generator, and the gas or liquid fuel that lights the stoves. Fuel is planned exactly as water and rations are, by consumption. Each thing that burns fuel does so at a rate, and the planner who knows that rate can work out how much fuel a task will need from the same simple arithmetic: the rate, times the running time or distance, times a margin. A vehicle burns roughly so much fuel over so many miles, so the fuel for a journey is the distance divided by the vehicle's economy, plus a margin for detours, idling, and the cold. A generator burns roughly so much an hour at a given load, so the fuel to run a base or a clinic is the hours it will run times that hourly rate, plus a margin. A stove burns a small but real amount to heat meals and boil water, and over days for a team it adds up to a quantity worth planning rather than guessing.

The margin matters for fuel as much as for water, and for the same reason: plans slip, tasks run long, the route is longer than the map promised, and the generator runs through a colder night than expected. A team that plans fuel to the exact figure has planned to run dry on the first delay, and a vehicle or generator that runs dry on a relief task takes a capability out of action at the moment it is needed. So fuel is planned generously, and resupply of fuel, like resupply of everything, is timed to arrive before the team runs short, never after. The table below shows the shape of a fuel estimate, again with illustrative figures to be replaced with the real consumption rates of the actual kit.

  FUEL PLANNING  (plan by consumption, then add a margin)

  VEHICLE     fuel = distance / economy            + margin
              e.g. 120 miles at the vehicle's
              rate -> work the litres, +20%

  GENERATOR   fuel = run-hours x burn-per-hour      + margin
              e.g. 10 hrs x its litres/hr
              -> work the litres, +20%

  STOVE       fuel = meals/brews x burn-per-use     + margin
              small per use, but adds up over
              a team over several days

  Then: SOURCE it, STORE it safely (see below), and resupply
  BEFORE the team runs dry, never after.

Fuel: storing and handling it safely

Fuel is the one commodity in this course that can hurt people if it is handled badly, and so it carries rules that the others do not. Petrol, diesel, and the gas and liquid fuels for stoves are flammable, their vapours can catch from a spark or a flame, and in a closed space those vapours can build up to a danger. None of this makes fuel something to be feared and avoided; it makes fuel something to be handled with a settled discipline that removes the danger. The rules are few and they are not negotiable, and a logistician keeps them whether or not anyone is watching, because the cost of breaking them is measured in burns and fires, not in paperwork.

Keep fuel away from ignition. Fuel and its vapours catch fire from sparks, flames, hot surfaces, and lit cigarettes, so fuel is stored and handled clear of any source of ignition, and there is no smoking and no naked flame near fuel or near refuelling. Keep fuel ventilated. Fuel vapour is heavier than air and pools in enclosed spaces, so fuel is stored and used where air moves, never sealed in an unventilated container store or a closed vehicle cabin, and a generator, which both burns fuel and gives off exhaust, is run in the open or with proper ventilation and never in an enclosed space where its fumes can gather. Keep fuel labelled and in proper containers. Fuel is held only in containers made and approved for it, each one clearly marked with what it holds, so that no one mistakes one fuel for another or fuel for water, and the containers are kept closed, secure, and clear of where people live and sleep. Handle it carefully. Refuel with the engine off and let it cool, avoid spills, clean up any spill at once, and keep the means to fight a small fire to hand. The checklist below gathers the rules into a form a storekeeper can run down before fuel is stored or moved.

  FUEL SAFETY AND STORAGE CHECKLIST

  AWAY FROM IGNITION
   [ ] stored/handled clear of sparks, flames, hot surfaces
   [ ] NO smoking, NO naked flame near fuel or refuelling
   [ ] refuel with engine OFF (and cooled)

  VENTILATED
   [ ] stored and used where air moves, never sealed in
   [ ] generator run in the OPEN / properly ventilated, never
       in an enclosed space (exhaust and vapour gather)

  LABELLED AND IN PROPER CONTAINERS
   [ ] only approved fuel containers, kept closed and secure
   [ ] each container clearly MARKED with its contents
   [ ] fuel kept apart from water and from where people sleep

  HANDLED CAREFULLY
   [ ] avoid spills; clean any spill at once
   [ ] means to fight a small fire kept to hand
   [ ] fuel accounted for: signed, recorded, stocktaken

  Rule: keep these whether or not anyone is watching.

Bringing it together: the power plan for a task

Put the two halves together and the lesson becomes a single product: the power plan for a team on a task. It is built like every plan in this course, from how many, for how long, doing what, in what conditions. The planner lists the devices and their batteries, sets a realistic life for each against the cold and the work, works out the spares, and names a charging source for every one, layering mains, vehicle, and solar so no single failure goes dark. Then the planner lists the things that burn fuel, works the fuel from their consumption rates with a margin, and plans where that fuel is sourced, how it is stored safely, and when it is resupplied. The radio's power sits at the top, planned with the signaller, because contact is the capability the team can least afford to lose.

Done well, none of this is visible on the task, and that is the mark of it. The radios stay up, the lights come on, the map is there, the vehicles move, and the meal is hot, and no one notices the planning that made it so. Done badly, it is the most visible failure of all: the team goes silent, the map goes black, the vehicle will not start, and someone calls it bad luck. It is not bad luck. It is the power plan that was not made.

In Practice: A two-night mapping and relief patrol

A section of eight is tasked for a two-night patrol in a generic rural area, mapping flood damage by day and sharing what it finds back to a headquarters, then returning. The team will carry radios, head torches, two phones holding the maps and notes, one TAK end-user device, and three Meshtastic nodes seeding a mesh across the section, and it will travel by one vehicle to a drop-off and patrol on foot from there. The Quartermaster NCO is asked to plan the power, and she starts where the lesson says to start, with the devices, building the battery table line by line. For the radios she plans fresh batteries at the start and two charged spares per set, because the radio is the line she cannot let fail, and she rings it in red on the plan with a note to the section signaller to change batteries before they die and to charge at every halt with a source. The torches she plans for two nights of a few hours each with spares to match; the phones and the TAK device she plans with a power bank each and a charge whenever power is at hand; the Meshtastic nodes, sipping power as they do, she plans to run on their own batteries with a small solar panel to trickle them through the daylight.

Then she writes the charging plan beside the table, and she layers it deliberately. There is no mains where the team is going, so the vehicle is the main charging source at the drop-off and the rendezvous, within limits, and she notes plainly that the vehicle's own starting battery is not to be flattened to charge devices, because a vehicle that will not start is a worse failure than a flat phone. The solar panel is the independent backstop for the small devices and the nodes, and the carried spares cover the gaps on the move. Fuel she plans next: the vehicle's fuel for the run out and back, worked from the distance and its economy with a fifth added for detours and idling, and a small reserve of stove fuel for hot meals and brews at the halts, which double as welfare and tie to Lesson 03. The fuel she has stored and signed in proper marked containers, kept clear of where the team rests and away from any flame, and she runs the fuel-safety checklist before it is loaded. Her finished power plan is one page: a battery table, a layered charging plan, a fuel estimate, and the fuel-safety check. On the task none of it is noticed, the radios stay up, the picture holds, the vehicle starts every time, and the meals are hot, which is exactly what a good power plan is meant to produce.

Check Your Understanding

1. A team will carry radios that each give about eight hours of battery life in use, and the radios will be needed for about twelve hours a day across a three-day task. Explain how you would plan the radios' power: how many spare batteries you would carry per set, and what your charging plan would be, given that no mains supply is available where the team is going.
2. Why does this lesson insist that a flat battery on task is a logistics failure rather than bad luck, and how does the radio's power in particular tie logistics (LOG) to communications (SIG)?
3. State the four headings of the fuel-safety and storage rules and give one practical reason behind each. Why is a generator never run in an enclosed space?

Reflection (write a short paragraph): Think of a time a device you depended on, a phone, a torch, a tool, ran out of power at a bad moment. Was it truly bad luck, or was it a plan that was not made? Relate your answer to why this lesson treats power as a commodity to be planned by consumption, with spares and a charging plan, exactly as water and rations are.

Summary

• Power is a commodity, not a given: stored energy in a battery or a fuel can is held in a known quantity, consumed at a rate, and runs out if it is not replenished before the team needs it.
• A flat battery is a logistics failure, not bad luck: plan batteries by device and by day, set a realistic battery life for the cold and the work, carry charged spares per device, and have a charging plan.
• Build the charging plan from mains, vehicle, and solar power, layered so the loss of any one source does not take the team dark; charge from the vehicle within limits so the vehicle's own battery is never flattened.
• The radio's power comes first and ties LOG to SIG: the logistician plans the spares and the charging, the signaller manages the changes and the routine, and together they keep the team in contact.
• Plan fuel for vehicles, generators, and stoves by consumption with a margin, and resupply before the team runs dry, never after.
• Store and handle fuel safely: away from ignition, ventilated, labelled and in proper containers, handled carefully, and never run a generator in an enclosed space.
• Bring it together as one power plan for the task; done well it is invisible, and done badly it is the most visible failure of all.
• Cross-references: builds on LOG 201 and on LOG 210 Lesson 01 (Sustaining a Force in the Field), Lesson 02 (Resupply and the Demand Cycle), and Lesson 03 (Water, Rations, and Welfare); leads to Lesson 05 (Transport, Load Planning, and Movement); ties directly to SIG communications training for radio power, and to FLD 210 Weapon Handling for the safe storage of kit.

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