What you actually need, what is pure marketing, and why most people buy the wrong thing
Article 5 in a series on practical civil preparedness for the Nordics
There is a product category that has exploded in the last five years. It sits near the checkout at outdoor stores, fills entire shelves at electronics retailers, and dominates preparedness forums. It is marketed as the solution to almost every power problem a modern household might face.
In most cases, it is completely misunderstood by the people buying it.
This article is about batteries — the portable kind. Power banks, portable power stations, solar-charged panels, and car inverters. The market is full of genuine value. It is equally full of expensive marketing, misleading specifications, and products that will fail you precisely when you need them most.
Knowing the difference is worth more than any individual purchase.
Why this matters more than it used to
In previous generations, “batteries” meant AA cells in a torch. Important, but peripheral.
Today, the picture is fundamentally different. Your phone is your map, your emergency radio, your news source, your way of contacting family, your payment terminal, and your flashlight. When the grid goes down, the phone is the last thing standing between you and complete informational isolation.
And the phone runs on a battery.
This is why the Ukrainian experience, documented in depth by Polish emergency preparedness authors (“Cywil na wojnie”) who spent time there, is so instructive. When rolling blackouts became part of daily life in Ukrainian cities — sometimes only a few hours of power per day — the single most fought-over resource wasn’t food or water. It was somewhere to charge a phone. Cafes that had power became gathering points. People planned their day around when electricity would arrive.
The lesson for Nordic households is simple: communication infrastructure is the first thing that breaks, and it runs on batteries.
Understanding what you’re actually buying
The powerbank market is large, confusing, and full of misleading numbers. Before you spend a single krone, understand three things.
Capacity is measured in milliampere-hours (mAh). A modern smartphone battery holds roughly 4,000–5,000 mAh. A 10,000 mAh powerbank will therefore charge a typical phone approximately once to twice, not twice as often as the number might suggest. This is because energy is lost during transfer (e.g., heat, conversion inefficiencies), typically 20–30%.
Wattage determines what you can power. A 20,000 mAh powerbank running at 5 volts delivers roughly 100 watt-hours of usable energy. That is enough to charge phones, run a DAB radio, or power small LED lights for hours. It is nowhere near enough to run a laptop at full load, heat anything, or drive a pump. Anything that generates heat — a kettle, a heater, a hair dryer — requires orders of magnitude more power than a portable battery can provide. The physics are non-negotiable.
Output voltage and wattage determine compatibility. Most power banks output 5V via USB-A or USB-C. If you need to power a laptop, look for USB-C Power Delivery (PD) output at 65W or higher. If you need 230V AC, you need a power station, not a powerbank — these are fundamentally different products.
The three products most people confuse
1. A power bank is a portable battery that charges devices via USB. Size ranges from 5,000 mAh (shirt pocket, one phone charge) to 50,000+ mAh (book-sized, can charge a whole family’s phones for several days). Prices range from 200 to 1,500 kr. For most households, a single quality 20,000–30,000 mAh unit is the single highest-value preparedness purchase available.
2. A portable power station is a much larger device — the size of a small suitcase, 500–2,000 Wh capacity — that outputs genuine 230V AC via a built-in inverter. Brands like EcoFlow, Jackery, and Bluetti dominate this market. These can run a CPAP machine, keep a small fridge cold, or power a laptop for days. They cost 5,000–20,000 kr. For households with medical equipment or families with small children, this is an excellent second investment — but it is not a replacement for a good power bank. It is an addition.
3. A solar-integrated powerbank — the small, flat devices with a solar panel stuck on the back — is, almost without exception, a waste of money. The solar cell area is so small that it cannot meaningfully charge the attached battery. In Nordic conditions, with low winter sun angles and frequent cloud cover, the “solar” function is essentially decorative. If you have seen one of these marketed as a preparedness solution and felt reassured, remove that reassurance.
The thing most people buy that fails them
The most common preparedness battery mistake in the Nordic context is buying a power bank and leaving it in a drawer at 15% charge.
A powerbank that is never charged is a plastic brick.
The habit is as important as the hardware. A power bank kept at 80–100% charge, checked monthly, and connected to the charging routine for everyday devices — phone, earbuds, watch — is genuinely useful. The same device neglected for three months is not.
The Polish guide to civilian preparedness in wartime is explicit on this point (“Cywil na Wojnie”): check the charge state of all power banks at least once a month, and top them up. The investment in the hardware is worthless without the discipline to maintain it.
There is one additional safety note from the same source, grounded in hard Ukrainian experience: be extremely cautious with improvised high-capacity battery solutions. Several fires and explosions occurred in Ukrainian cities when people attempted to use repurposed electric-vehicle or e-scooter batteries as home power sources. A quality commercial powerbank or power station from a reputable manufacturer is safer, better managed, and — when you factor in the cost of a fire — cheaper.
Tip: thinking in terms of dual-use is a smart way to make sure the equipment you use will also serve you in daily life. An example of this is the power bank adapter for electric tool batteries.
A small, relatively inexpensive adapter will let you use the multiple batteries you already have at home, they tend to have moderate capacity (max 4-6 Ah) but the sheer number of those is a significant resource in itself
Photo: Bosch / example of a power bank adapter for Universal 18V power tool battery
Your car as a power source
This one is underused and underappreciated.
Most cars have a 12V cigarette lighter socket. A simple inverter — available for 150–300 kr — converts this to 230V AC. This is not enough to run anything that generates heat, but it is entirely sufficient to charge phones, power banks, laptops, and small medical devices.
One rule applies without exception: the engine must be running while you charge. Charging from a parked, switched-off car will drain the starter battery and leave you unable to start the vehicle. More importantly, never run a petrol or diesel engine in a garage, not even with the door open. Carbon monoxide is colorless, odorless, and lethal within minutes. This is not a theoretical risk. It kills people every winter.
And if you have an EV, chances are it also has V2L (vehicle-to-load) and includes V2L adapters to supply power without extra inverters.
The honest buying guide
If you have nothing right now, start here:
Step 1 — A quality 20,000 mAh powerbank. Budget 400–800 kr. Brands like Anker, Baseus, or similar reputable manufacturers. Look for USB-C PD output if you own a laptop. Keep it charged. This is your first line of defense and covers the most critical need: keeping phones alive.
Step 2 — AA and AAA batteries, stored in quantity. Your DAB radio, head torch, children’s toys in a crisis, and dozens of other devices run on these. Buy quality alkaline cells (Duracell, Energizer) — cheap generics degrade and can leak. Store them in a cool, dry place. Check expiry dates.
Step 3 — A battery-powered DAB radio. This is not technically a battery product, but it belongs in this conversation. When the internet and mobile networks fail, DAB radio from NRK is how official information reaches you. DSB explicitly lists this as essential. A radio that runs on AA batteries lasts as long as you have batteries.
Step 4 — Consider a portable power station if you have medical equipment at home, small children, or a home office that needs to remain operational. This is a significant investment, but the per-hour cost of maintaining warmth, light, and communication is real.
What the Norwegian authorities actually say
DSB’s preparedness guide lists “batteries and charged power banks” explicitly in its household checklist. It is a short line in a longer document. But its placement is deliberate — it sits alongside the DAB radio, the torch, and the matches, in the section about maintaining communication and light.
The underlying logic is sound: in the first hours and days of any serious disruption, what you need most is information, communication, and the ability to see in the dark. All three are battery-dependent.
The best time to buy and charge a power bank was last year. The second-best time is today.
A note on what batteries cannot do
This article should not end without acknowledging the limit.
Portable batteries can maintain communication. They can keep the lights on. They can run small medical devices. They cannot heat your home. They cannot pump water into your apartment if the municipal system fails. They cannot power an electric cooker.
For those needs — heating, cooking, water — different solutions are required, and they will be the subject of upcoming articles in this series. Batteries are not a complete preparedness solution. They are the first and most accessible layer.
Know what they can do. Know what they cannot. Buy accordingly.
Views expressed are my own.
Next week: Article 6 — “When the Tap Runs Dry: Water Storage, Filtration, and What You Actually Need for a Week Without Running Water.”
I write about Total Defense, civil preparedness, and resilience from a Nordic perspective. Follow for weekly posts. Questions, challenges, and additions are welcome in the comments.
References: “Cywil na Wojnie” by Kaczor, Kafir
This work, excluding photos, is licensed under a Creative Commons Attribution 4.0 International License.