
In times of crisis—whether stemming from natural disasters, civil unrest, or widespread infrastructure failures—knowledge of basic electronics and power management can be invaluable. Urban SERE (Survival, Evasion, Resistance, and Escape) principles focus on staying safe, maintaining communication, and making use of whatever resources are available in a city environment. While traditional SERE concepts might bring to mind wilderness scenarios, urban settings present different challenges and opportunities. Amid disrupted power grids, damaged communication networks, and potential shortages of resources, your ability to harness and conserve power for essential electronics can make a significant difference.
Below, we will delve into the fundamentals of electronics and power management in an urban crisis scenario: identifying power sources, protecting your electronic devices, safe battery management, and tips for scavenging or generating electricity when the grid is down.
Electronics & Power Management Matter in Urban Crises
Electronics play a central role in modern life. When crisis strikes, the information and communication capabilities offered by devices like cell phones, two-way radios, and tablets become even more crucial. According to the Federal Emergency Management Agency (FEMA), “Communication tools are often vital in emergencies for accessing critical updates and contacting loved ones” (FEMA, 2021). Being unable to charge or protect these devices can mean losing access to weather alerts, important evacuation instructions, or emergency services.
Additionally, electronics can support essential tasks such as: (links benefit the author)
Lighting: Flashlights and headlamps powered by batteries or rechargeable cells.
Navigation: GPS devices or map applications on smartphones.
Information gathering: Local news apps, emergency broadcasts, and online resources.
Coordination & communication: Texting, phone calls, or radio transmissions to organize or request assistance.
Understanding Power Basics: Voltage, Current, and Capacity
Before diving into specific strategies, it helps to understand a few electrical fundamentals:
Voltage (V): The electric potential difference, determining how strongly electricity flows. Common battery voltages include 1.5V (alkaline AA/AAA cells), 3.7V (lithium-ion cells), 12V (car batteries), and so on.
Current (A): Measured in amperes, current is the rate of electrical charge flow. Higher current draw depletes batteries faster.
Power (W): Measured in watts, calculated as Voltage × Current. For instance, a 5V phone charger that pulls 2A of current is using 10W of power.
Capacity (mAh or Ah): A measure of how much charge a battery can hold. A 2000mAh (milliamp-hour) battery theoretically can supply 2000mA for one hour, or 1000mA for two hours, etc., under ideal conditions.
Understanding these basics helps you estimate how long your devices can run on a given power source and what you’ll need to recharge them.
Securing and Protecting Your Electronics
Waterproofing and Shock Protection
In post-disaster urban environments, water intrusion and physical shock are real threats. Protect devices using sealable plastic bags or waterproof phone cases. The Centers for Disease Control and Prevention (CDC) recommends storing electronics in watertight containers in flood-prone areas (CDC, 2022). Where possible, add cushioning (bubble wrap, foam, or even layers of cloth) around delicate electronics.
EMP (Electromagnetic Pulse) Concerns
While full-scale EMP events are less likely in most disasters, some urban preppers choose to safeguard critical electronics (like radios or portable chargers) in improvised Faraday cages—metal containers that can block electromagnetic fields. Even wrapping devices in aluminum foil (several layers) or placing them in a metal ammo can lined with non-conductive material can help mitigate certain electromagnetic threats, although official studies vary in how effective these methods may be (Department of Homeland Security, 2020).
Physical Security
In times of civil unrest, theft is a concern. Keep electronics discreet and stored securely. Consider distributing them among different bags or pouches instead of one obvious “tech” bag.
Common Power Sources in an Urban Environment
Grid Power (Limited or Intermittent)
If power is partially available in some areas, be mindful that rolling blackouts or unstable voltage surges can damage equipment. Consider using a surge protector or uninterruptible power supply (UPS), although this may be impractical if you’re on the move.
Car Batteries & Vehicle Cigarette Lighter Ports
Vehicles can be a lifesaver for charging phones or powering small inverters. A standard car battery provides about 12V, which can be stepped down to 5V via USB adapters. If using the battery directly (with an inverter or cables), be aware of the risk of draining the battery to the point the vehicle no longer starts.
Portable Battery Packs
High-capacity lithium-ion battery packs are a mainstay of modern emergency kits. Choose models with multiple charging ports and a built-in charge indicator. The American Red Cross suggests having at least one fully charged power bank in your emergency kit (Red Cross, 2022).
Renewable Sources: Solar and Hand-Crank Devices
Solar Chargers: In an urban environment, tall buildings may limit sun exposure, but rooftop access or open areas can provide enough light to trickle-charge small solar panels. Aim for models that produce at least 10W to 20W for reasonable recharging speed.
Hand-Crank Generators: These are typically low-power solutions suitable only for emergency phone calls or short bursts of communication. Still, they can be a lifeline if all other power sources fail.
Generators and Inverters
Gasoline or diesel generators can be found or purchased for larger-scale power requirements. Always operate them in well-ventilated areas to prevent carbon monoxide poisoning. If you have access to an inverter, you can convert DC power (e.g., from a car battery) to AC power for running small household devices.
“Carbon monoxide is an odorless, colorless gas, and its fumes can kill you.” (U.S. Consumer Product Safety Commission, 2021)
Battery Management and Safety
Battery Types
Alkaline (AA, AAA): Easily found, but not rechargeable. Store spares in a cool, dry place.
Nickel-Metal Hydride (NiMH): Rechargeable alternative to alkaline. Useful for flashlights, radios, and some medical devices.
Lithium-Ion (Li-ion): High capacity, common in portable battery packs and modern gadgets. Sensitive to overcharging, high temperatures, and physical damage.
Lead-Acid: Found in car batteries and some backup systems. Heavier but can supply significant power.
Storage and Maintenance
Keep batteries at moderate temperatures. Extremely cold or hot environments reduce lifespan and capacity. Whenever possible, store lithium-ion batteries at around 40–60% charge if they’re not in use for an extended period.
“Batteries stored in hot environments degrade more quickly, reducing their overall service life.” (Department of Energy, 2020)
Safe Charging Practices
Use the correct chargers for each battery type. Overcharging or using incompatible chargers can cause overheating or fires. Inspect batteries regularly for bulging or discoloration. If found, discontinue use immediately.
Improvising and Scavenging Power
In severe crises, you may need to improvise power solutions:
Abandoned Buildings & Infrastructure
In a grid-down scenario, certain parts of the city may still have partial power or functional backup systems—like hospitals, office buildings with solar setups, or telecom relay stations. Accessing these locations, however, may involve legal and safety risks. Always prioritize your well-being and follow local regulations if possible.
Scrapping Electronics
Salvaged devices can provide spare batteries, charging cables, and connectors. Exercise caution: take the time to identify correct polarities and voltages before attempting to repurpose components.
Renewable Scavenging
Small Solar Lights: Garden solar lights can sometimes be repurposed into small charging solutions. Each light typically has a tiny solar panel and a rechargeable battery. Wiring multiple units together can provide a bit more power.
Kinetic Generators: If you have time and resources, you might build or adapt a hand-crank or pedal-power generator using basic hardware. This can be complex but may pay off in a prolonged emergency.
Effective Power Consumption Strategies
Device Prioritization
During extended crises, prioritize which devices truly need power. Communications and lighting usually top the list, while entertainment devices are secondary.
“In times of emergency, ensuring adequate backup power for critical communication devices can save lives.” (FEMA, 2021)
Energy-Saving Modes
Modern smartphones and many radios have power-saving modes. Keep screens dim, limit background apps, and turn off wireless functions (Bluetooth, Wi-Fi) when not needed.
Scheduled Use
If power is scarce, schedule device usage times—e.g., powering a phone for 15 minutes every few hours to check for updates or messages.
Sharing Resources
In a group scenario, share battery packs or chargers. Pooling resources can extend overall operational capacity, especially if one person has a solar charger while another has a car battery.
Testing and Practice
As with any survival skill, practice is key. Familiarize yourself with your gear before disaster strikes. Run drills where you simulate power outages for 24–48 hours. Test your solar chargers, battery packs, hand-crank radios, and inverters. Notice how quickly batteries deplete under different loads. This real-world experience will be invaluable in an actual crisis, where quick adaptation can be lifesaving.
Conclusion
Urban SERE scenarios demand a strategic approach to electronics and power management. By understanding electrical basics, safeguarding devices, identifying and utilizing available power sources, and managing your battery usage, you maximize your ability to communicate, gather information, and stay safe. In many disasters, your ability to keep a phone, radio, or flashlight running can determine whether you receive timely evacuation orders, locate safe shelters, or call for rescue.
As you refine your urban survival plan, include a robust strategy for power continuity. Stay up to date with government recommendations from sources like FEMA and the Red Cross, and ensure your gear is tested and maintained. By doing so, you’ll be better prepared for whatever urban challenges lie ahead—maintaining the critical lifeline that electricity provides amid crisis.
References
Federal Emergency Management Agency (FEMA). (2021). Emergency Communication. Retrieved from https://www.ready.gov/communication
Centers for Disease Control and Prevention (CDC). (2022). Floods. Retrieved from https://www.cdc.gov/nceh/features/flood-safety/index.html
Department of Homeland Security. (2020). Strategy for Protecting and Preparing the Homeland Against Threats of Electromagnetic Pulse and Geomagnetic Disturbances. Retrieved from https://www.dhs.gov
American Red Cross. (2022). Prepare for Emergencies. Retrieved from https://www.redcross.org/get-help/how-to-prepare-for-emergencies.html
U.S. Consumer Product Safety Commission. (2021). Carbon Monoxide Information Center. Retrieved from https://www.cpsc.gov/Safety-Education/Safety-Education-Centers/Carbon-Monoxide-Information-Center
U.S. Department of Energy. (2020). Batteries for Hybrid and Plug-In Electric Vehicles. Retrieved from https://www.energy.gov/eere/vehicles/batteries
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