Output varies a lot by design and how fast you crank, but it’s typically modest. As a general guide:

• Compact, pocket-style units: often around 3–10W continuous for phone trickle charging and small lights.
• Mid-size, box-style cranks: commonly in the 10–30W range with 5V USB and some multi-voltage options.
• Higher-output models: some list 60W-class USB-C/PD bursts, but sustaining that by hand can be challenging.

That’s enough for phones, radios, flashlights, and topping up power banks, not household appliances. Actual performance depends on gearing, the device’s regulator, cable quality, and your effort. For the most usable energy, many people crank in intervals and store it in a power bank first.

They can be a smart add-on for emergency kits or off‑grid travel when you want power without fuel or sunlight. Consider them when:

• You need reliable basics: keeping a phone, radio, or headlamp going during outages or camping.
• Space matters: they’re compact and easy to stash.
• You prefer manual backup: works day or night, indoors, and during cloudy weather.

Keep in mind they’re manual and low output, so they’re not ideal for large or power‑hungry devices. Pairing one with a power bank can make the energy you generate more practical. If you expect to run bigger gear, consider combining it with other charging options.

Match the features to what you want to power and how you’ll use it:

• Outputs and voltage: USB‑A for basics, USB‑C/PD for faster devices, and multi‑voltage (e.g., 3–15V/12V/28V) for specialty gear.
• Rated wattage: 20W class for light charging; higher ratings may support faster top‑ups (actual results vary by effort).
• Built‑in storage: Some include a small battery to smooth power and charge while you rest.
• Durability: Metal cases, water resistance, and shock protection can help in the field.
• Ergonomics: Comfortable handle, stable base, and clear indicators (like an LCD voltmeter).
• Extras: Flashlight, radio, SOS beacon, or fire‑starting tools for all‑in‑one emergency kits.

It depends on your phone’s battery size, the crank’s output, and how steadily you can turn the handle.

• Rough math: A 4,000 mAh phone (~15 Wh) might need ~20–25 Wh allowing for conversion losses. At a steady 5–10W, that could be a few hours of total cranking time, usually done in shorter sessions.
• Top‑ups: A quick 10–20 minute spin may add useful percentage points for calls or texts.

Tips to make it count: charge a power bank first, switch the phone to low‑power/airplane mode, dim the screen, and use good cables. If the unit warms up, give it a rest. Actual times vary by model, settings, and effort.

Laptops often need 30–65W to charge, which is more than many hand cranks can deliver continuously. Here’s how to approach it:

• Check power needs: If your laptop can accept lower‑wattage USB‑C/PD (e.g., 15–30W), some higher‑output cranks may provide a slow charge in short sessions.
• Use a buffer: Charging a compatible power bank first and then the laptop tends to be more practical and gentler on the crank.
• Match voltages: If using multi‑voltage DC outputs (like 12V/28V), verify compatibility and use the correct adapter.

Keep expectations realistic, avoid unregulated connections to sensitive electronics, and follow the product manual for safe, stable use.