Note: *The high output is measured at total run-time, including output at reduced levels due to temperature or the built-in protection mechanism. That app is essential because there's a Find My feature built into the battery. It doesn't work like an AirTag over UWB, it's only Bluetooth, but it's useful if you misplace your battery in your office (or you have multiple batteries, like I do). When a device is plugged in to either the USB-A or USB-C output the four LED indicators will decrease from right to left as the battery is drained. The torch can still be used while being discharged, but can only access eco, low or mid modes and the charging time will be prolonged as well as drain the battery faster.

Firstly, think about how much power you’re likely to need and how long you might be away from a power source. This will dictate what size power bank you need in terms of battery capacity, which is usually measured in milliamp hours (mAh). The body is made from carbon fiber reinforced polymer and has a hollowed frame to give the NB20000 its lightweight design, but also provide high strength and impact resistance to protect the cell. The interwoven carbon fiber sheets stabilise the cell for safe use, and the power bank has multiple safeguards such as overcurrent, short circuit, over-discharge, over charge, over voltage and thermal protection. If you need serious power and a light beam that will be seen (and see) for miles, look for a heavyweight floodlight-style model with in excess of 1,500 lumens. These monsters are heavy and large (often more than 20 cm long), but they have the power to turn night into day at the press of a button. They can usually be set to provide either a football stadium-like super-wide beam or one that sharpens to highlight subjects up to a kilometre away. The three blue indicators will also display battery status so you always know how much power you have by tapping the torch icon on the side, or while being discharged. Three lights is 100%, two lights is 70%, one light is 30% and the last light flashing means the battery is near depletion and requires charging.The MH23 comes with five different beam strengths, from one lumen – just bright enough to see by without attracting attention – to a mind-bending 1,800 lumens. It also features an emergency strobe and SOS, plus a very cool locator beacon built into the torch button that gently flashes intermittently so it can be found in the darkness of a tent. It is perfect for charging a range of devices such as torches, mobile phones, tablets etc via the standard USB-A port on the top with a QC 3.0 output of up to 2.4 A (18 W max), and is compatible with the Nitecore HU60 USB head torch. To be more precise, the average LED consumes about 12% of the energy used by halogen and filament bulbs to emit the same amount of light, and will go on burning for hours, if not days, on the same set of batteries. An average LED has a lifespan of up to 50,000 hours, while a filament bulb will fizzle out at around 2,000 hours. Whichever model of torch you select will likely provide many years of useful service. What size or type of LED torch should I buy?

The best rechargeable LED torches will be impervious to rain and will come with an IP rating. IP (ingress protection) is an indicator of how well protected an electrical device is from substances such as dust and water. For a torch you plan you use outdoors, a rating of IPX4 is a minimum starting point. IPX4 will cope with drizzle and light moisture. For the best protection, IP67 or IP68 is needed. Rechargeable vs disposable batteries In addition to the power bank function, the PB-7800 also has a torch function in the top with a maximum output of 250 lumens cool white light from a SMD LED.The Anker Prime series of Power Banks, including the Anker Prime 27,650mAh Power Bank (250W) and the Anker Prime 20,000mAh Power Bank (200W), are for people who truly love to geek out on power banks. If you came looking for the absolute best power bank you can buy, this is the best we've tried. The Nitecore NPB1 is a compact and lightweight power bank equipped with a built-in 5000 mAh 21700 lithium-ion battery. Key specs – Length: 77mm; Width: 22mm; Max lumens: 800; Min lumens: 10; Max beam distance: 126m; Max runtime: 17hrs The best power banks we have tried have all come from Anker, but that doesn't mean Anker is the only brand you should consider. All of the power banks on this list passed our testing, traveling with us on the road and powering our devices at home. Anker is the best, but these batteries from Baseus and Otterbox performed well. Pros: Striking a good balance between capacity, weight and size, this is a versatile all-rounder at a competitive price. For us, it’s the best value option in this test. The triple outlet ports are very useful, while USB-C input/output supports the latest devices and permits rapid mains charging.