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How to Choose Reliable Portable Power Sources for Military Missions

Choosing power is a planning problem, not a shopping problem. Follow these eight steps — the same method NUE engineers use — and the right equipment selects itself.

NUE Field GuideUpdated Nov 202610 min read
The short answer

To choose reliable portable power for a military mission: (1) list every device and its average watts, (2) multiply by hours to get daily Wh, (3) define the longest period without recharge, (4) size storage at that energy ÷ 0.85, (5) choose recharge sources — solar, vehicle, fuel cell — sized to daily Wh, (6) match outputs and peak watts, (7) set weight and signature limits, and (8) plan sustainment and redundancy.

BudgetWatts × hours, per device.
GapLongest time without recharge.
StoreEnergy ÷ 0.85.
RefillRecharge ≥ daily use.

01The 8-step method

  1. Inventory the loads

    List every device: radios, chargers, SATCOM, EUDs, laptops, drones, lighting, medical. Note connection type (AC, 12/24 V, USB-C) and average watts.

  2. Build the power budget

    Multiply each device's average watts by hours of use per day. Sum to get daily Wh. Add 20% margin.

  3. Define the recharge gap

    How long must you run with no recharge — overnight, a 48-hour storm, a silent-watch window?

  4. Size the storage

    Storage Wh = (average W × gap hours) ÷ 0.85. Round up to real units; prefer two smaller units over one large for redundancy.

  5. Choose recharge sources

    Solar W ≈ daily Wh ÷ (sun-hours × 0.75). Add vehicle DC for mobile units and a fuel cell for sun-limited missions.

  6. Match outputs and peaks

    Inverter continuous watts ≥ 1.25× simultaneous AC load. Use DC outputs for DC loads.

  7. Set mobility and signature limits

    Who carries it, how far, and in what threat environment? Add thermal mitigation for observed positions.

  8. Plan sustainment

    Spares, cables, training, storage at partial charge, and a support contact.

02Worked example: 72-hour drone team mission

DeviceAvg WHours/dayWh/day
sUAS battery charger1506900
Ground control station / laptop4510450
Goggles / monitors208160
EUDs × 44 each24384
Radio battery charging306180
Total (+20% margin)≈ 2,490 Wh/day
Planning values for illustration.

With a 14-hour overnight gap at roughly 90 W, the team needs about 1,500 Wh of storage → one SunCase 1213 (~1,100 Wh usable) plus a SunCase 605, or a single SunCase 2425. Daily solar: 2,490 ÷ (5 × 0.75) ≈ 660 W → three SunFold240™ modules. Add SunStealth™ for observed positions.

From budget to kit
01Loads2,490 Wh/day02Storage≈1,500 Wh03Solar3 × 240 W04Kit1213 + 605 or 2425
Interactive

Runtime & sizing calculator

Enter your average load. Runtime uses 85% usable energy after inverter and conversion losses.

–hours runtime
–Wh needed for mission
–units required (no solar)
–SunFold240 panels to sustain (5 sun-hrs)

03Reliability multipliers

N+1 storageTwo units beat one: a failure halves capacity instead of ending the mission.
Two recharge pathsSolar plus vehicle or fuel cell.
Common connectorsFewer adapters, fewer failures.
Pre-mission testRun the full load on the actual kit for 24 hours.
TrainingEvery operator can deploy, connect and recharge the system.
DocumentationManual, quick-start and support contact in the case.
Individual operator / drone team
SunCaseâ„¢ 605
Output
600 W pure sine
Storage
~550 Wh LiFePO4
Weight
16 lb (7 kg)
Solar in
400 W MPPT, 13–100 V

Ruck-portable, IP55, AC + USB-A + USB-C + 12 V DC. Recharges from solar, AC or vehicle.

View SunCaseâ„¢ 605Get a configured quote

04Frequently asked questions

How do I calculate power needs for a military mission?
Multiply each device's average watts by hours of use per day and sum them for daily watt-hours. Add a 20% margin, then size storage for the longest period without recharge and size recharge sources to at least the daily total.
How much battery do I need for a 72-hour mission?
It depends on recharge. With no recharge, storage must cover the full 72 hours of energy divided by 0.85. With daily solar, storage only needs to cover the longest overnight or bad-weather gap.
Is one large power station better than several small ones?
Several smaller units add redundancy and are easier to carry, while one large unit offers more output per inverter. Many teams use a mix.
What is the most reliable recharge source in the field?
Solar is the most sustainable because it needs no resupply, but it depends on weather. Pairing solar with vehicle charging or a fuel cell gives the most reliable result.

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Published by New Use Energy (NUE), a veteran-led portable power company and manufacturer of the SunCaseâ„¢ line. Where we compare our products to other categories or companies, we say so. Specifications are nominal; confirm the current datasheet before procurement. Planning figures for device loads are typical values; measure your own equipment. Last updated 2026-11-03.

We Serve Powerâ„¢

Size your power plan with an NUE engineer.

Tell us your loads, mission length and recharge options. We will spec the SunCase, solar and stealth configuration — and quote it with published pricing.

Talk to a power engineerShop SunCaseâ„¢+1 (844) 941-3476