Power and Lighting

The single most useful habit when buying emergency power is to stop thinking in milliamp-hours and start thinking in watt-hours, because that is the unit that tells you what a device can actually run. A phone battery stores somewhere between 12 and 18 watt-hours. A 20,000 mAh power bank is marketed on its cell capacity, but once you account for the 3.7 V cell voltage and the losses in stepping up to 5 V USB, the usable output is around 55 to 60 watt-hours. That means three or four full phone charges in the real world, which is genuinely useful for a 48-hour outage but a long way from the inflated figures on the box.

When phones and a torch are not enough, the next tier is a portable power station, essentially a large battery with mains-style sockets. A unit in the 200 to 500 watt-hour range is the sweet spot for most homes: it will recharge laptops and phones many times over, run LED lighting for days, and keep a CPAP machine going through the night, which is the requirement that pushes a lot of households from "nice to have" to "essential". You only need to step up into the 1,000 watt-hour-plus class if you intend to run something with a heating element or a compressor, such as a small fridge, a kettle or power tools, and at that point weight and price climb steeply.

The trap at both ends is real. People over-buy a heavy power station they never charge or test, then find it flat when they need it; or they under-buy, assuming a single power bank will cover a family for three days. The fix is to size against a short written list of must-run devices and their daily watt-hours, add a sensible margin, and stop there. In every prolonged outage I have followed closely, the households that coped were not the ones with the most kilowatt-hours on a shelf — they were the ones whose modest capacity was charged, labelled and matched to a need they had actually thought through.

Emergency lighting is judged by how usable it is at 3am when you are cold and half-asleep, not by the headline lumen count. For almost everything you do indoors during an outage — finding the stopcock, reading a label, helping a child to the bathroom — 100 to 300 lumens is ample, and a high-lumen torch mostly buys you a shorter runtime and a hotter hand. The most underrated piece of lighting kit is a simple headlamp, because it points where you look and leaves both hands free to actually do the task. A small LED lantern that throws light in every direction is the other quiet workhorse, far better than a torch for lighting a room while a family sits together.

Power source is where lighting setups quietly fail. A rechargeable torch is convenient until the day the charge has leaked away in a drawer, so the strongest setups are hybrids: a rechargeable primary light plus at least one unit that takes standard AA or AAA cells, with a sealed pack of spares stored alongside. Standardise on one or two battery sizes across your torches, radio and any other gear so a single pack of spares serves everything. Lithium AA cells are worth the premium for emergency stores because they hold charge for a decade and tolerate cold far better than alkalines.

A word on candles, because they come up every time: they are a last resort, not a plan. An open flame in a dark, possibly crowded home with children or pets is a genuine fire risk, and the light they give is poor. Keep a few for morale or a total kit failure, but do your real lighting with LEDs. Finally, store the lights where you will find them without power — a torch in a known spot by each bed and one by the consumer unit — because a brilliant lantern buried in a loft box is no use when the room goes black.

When the grid goes down the mobile network often follows, either immediately or once local mast batteries drain after a few hours. That is the moment a simple battery or wind-up radio earns its place, giving you official broadcasts and weather warnings when your phone shows no signal. Many emergency radios double as a torch and a small USB charger, which is convenient, but treat the built-in dynamo as a trickle for a single emergency call rather than a serious power source — a minute of frantic cranking yields only a few minutes of talk time. Buy the radio for the radio, and rely on your power bank for charging.

Charging strategy is what ties the whole category together. Keep power banks and any station near full between events, because a battery slowly self-discharges and a flat power bank discovered mid-outage is a familiar disappointment. Charge phones to 100% the moment a storm warning lands, switch them to low-power mode early to stretch each charge, and resist topping up non-essential devices in the first day until you know how long the outage will last. If you own a solar panel, deploy it at first light to claw back some of what you used overnight, accepting that it is a slow drip rather than a tap.

The recurring lesson from real outages is how ordinary the winners look. They are rarely the people with the largest battery on the wall; they are the ones whose phone stayed charged because they topped it up early, who could see what they were doing because a headlamp was where they left it, and who knew what was happening because a cheap radio kept working when the network did not. A layered, tested, modest setup beats an expensive one you have never switched on.