Hand Crank Generators
Hand crank generators provide power to the most basic equipment in emergencies - radios and radio beacons, smartphones, navigation lights, jump starters, power banks, and similar.
Hand crank generators are able to provide from just a few watts to tens of watts of power and they are mostly suitable for charging USB charged devices. While larger pedal-powered manual power generators are able to provide 2-3 Amps @12V continuously, they would require up to 10 hours to charge the 12V battery with 25-30Ah and as such, they are not the best solution for charging the main car/boat battery in an emergency.
Published: December 20, 2021.
On This Page:
- Hand Crank Generators Overview
- Emergency Weather Radios
- Hand Crank Flashlights
- Manual Power Generators/Chargers
- Pedal Bicycle Power Generators
- Hand Crank Power Generators FAQ
- Few Final Words
Hand Crank Generators Overview
Hand crank power generators are commonly found as part of other devices, most commonly, as part of emergency weather radios, flashlights, USB chargers, and similar.
However, some manufacturers offer hand crank (manual) power generators as standalone units with several output ports, allowing the user to directly charge USB charged devices like smartphones, drones, tablets, flashlights, jumpstarters, and similar.
Thanks to the miniaturization in electronics and chemistry, hand crank generators are compact, versatile, affordable, and best of all, low-maintenance and reliable devices that should be part of any hiking, fishing, camping, hunting, or similar trip. Also, just in case, one or two such devices can be kept at home all the time.
When hand crank power generators are combined with foldable solar panels chargers, users have access to electric energy practically 24/7, regardless of the kind of emergency or trip.
How Does a Hand Crank Generator Work?
Operation is rather simple - the user cranks the handle at a constant pace, powering the small alternator (electric generator) which in combination with the built-in charge controller charges the internal battery (if available) and charges the device connected to the hand crank generator.
To keep the weight as low as possible, ultralight lithium-ion batteries are used, most commonly 18650, 26650, and 32650 batteries.
To help users recharge their devices, hand crank generators often feature small solar panels and a USB charging (input) port. Also, lithium-ion batteries (or battery) are often removable, allowing the users to recharge them directly in the dedicated wall battery chargers.
Emergency Weather Radios
Emergency weather radios are compact, unusually versatile and often rather valuable devices.
By default, emergency weather radios allow the user to listen to National Oceanic and Atmospheric Administration (NOAA) weather information 24/7 broadcasts.
But, most emergency weather radios also feature:
- classic AM/FM radio,
- replaceable lithium batteries,
- hand crank generator,
- solar panel,
- LED flashlight,
- USB charging ports (both in and out ports).
And best of all, weather radios are relatively cheap and their USB ports can be used to charge a broad range of USB-charged devices, including smartphones, tablets, flashlights, car jump starters, two-way radios, power stations/solar generators, power banks, etc.
There are many emergency weather radios on the market, and many of them have thousands of excellent reviews - here are just a few of them that we really think are among the best ones:
RunningSnail 6000mAh Emergency Weather Radio
RunningSnail 6000mAh Emergency Weather Radio features physical dimensions of 6.3 x 2.48 x 3.19 inches (~16 x 6.3 x 8.1 cm) and weighs only 13.6 oz (~380g) and comes with AM/FM/NOAA radio, hand crank generator, replaceable 3.7V 6000 mAh lithium batteries, built-in solar panel, high-lumen LED flashlight, reading flashlight, SOS audio alarm.
Also, RunningSnail 6000mAh Emergency Weather Radio can be used as a small power bank to charge other devices via USB port and it can also be charged via micro-USB port.
RunningSnail 6000mAh Emergency Weather Radio even comes with a motion sensor that automatically turns on the reading lamp and turns it off after 30 seconds. This feature, for example, can help users find their way in the dark in a new environment, or it can be placed around the tent - if some animal activates a motion detector, a reading lamp will be turned on and hopefully scare the animal away (just a suggestion...).
- the solar panel is small and its intended use is to keep the batteries fully charged. If the solar panel is used to recharge the batteries (3.7V, 6000 mAh), it will take up to 140-150 hours (6-7 days) to fully recharge the batteries!
- using a micro-USB port, users can recharge the batteries in 7-8 hours - this is the best and quickest way to charge the batteries while still in the unit. This power doesn't have to come from the wall charger - there are many foldable solar USB chargers on the market that are compact and ultralight.
- 1 (one) minute of continuous cranking of the hand crank generator at 130 rpm in a clockwise or counterclockwise direction, supports over 30 minutes of light or 5-6 minutes of radio work.
Also, batteries are replaceable - if You want to recharge them faster, charge them using a regular lithium battery charger.
All in all, RunningSnail 6000mAh Emergency Weather Radio alone or combined with other devices for emergencies can come in very handy. Also, it can be used on a daily basis, after all, but also for hiking, camping, fishing, etc.
For more reviews and recommendations, feel free to check the RunningSnail 6000mAh Emergency Weather Radio Amazon link (link opens in the new window).
FosPower A3 4000mAh NOAA Emergency Weather Radio
FosPower A3 4000mAh NOAA Emergency Weather Radio comes with all features required/recommended for an emergency weather radio, including AM/FM/NOAA radio, hand crank generator, solar panel, two flashlights (high output flashlight and reading flashlight), 3.7V 4000 mAh battery pack (2x 18650, 3.7V, 2000 mAh), and USB charging ports allowing the user to recharge the unit via micro-USB port and to charge other devices via charging 5V 1.0A USB port.
Note: 18650 lithium batteries are replaceable - since FosPower A3 4000mAh NOAA Emergency Weather Radio is a relatively low drain device, feel free to replace this pair of 18650 batteries with high-quality and high-capacity 18650 lithium-ion batteries.
FosPower A3 emergency weather radio features 5-6 hours charging time, while the batteries may be recharged using an external battery charger a little bit faster.
Also, the solar panel is large enough to allow the user to keep the batteries fully charged, but it can't recharge the batteries quickly.
FosPower A3 emergency weather radio also comes with a motion sensor, sensitive enough to detect human-size objects within 10 feet (3 m) - 30 seconds after no motion is detected, the reading flashlight will automatically turn off.
FosPower A3 emergency weather radio can be combined with other devices suitable for emergencies (or camping, hiking, etc.), like solar USB chargers, power stations, power banks, etc. to ensure that the USB-powered devices are fully or almost fully charged.
For more reviews and recommendations, feel free to check the FosPower A3 4000mAh NOAA Emergency Weather Radio Amazon link (link opens in the new window).
Raynic 5000mAh Solar Hand Crank Emergency Radio
Raynic 5000mAh Solar Hand Crank Emergency Radio features AM/FM/SW/NOAA radio, hand crank generator, single 3.7V 5000 mAh 21700 battery, 3x AAA battery pack (not included), USB charging ports, 3.5mm audio port, magnetic compass, two flashlights, solar panel, etc.
Its physical dimensions are 7.5 x 3.5 x 4.7 inches (~19 x 8.9 x 12 cm) and it weighs 1.2 pounds (~0.55 kg).
A high-output LED flashlight is rated at 3W, while the reading lamp features 2.5W.
In ideal conditions, solar panel power is ~45 mA - it takes up to ~110-120 hours to recharge the main battery using solar panel in almost ideal conditions.
Hand crank power generator is able to provide ~350mA - it takes up to 15-16 hours to fully recharge the single 21700 lithium battery.
But, the unit comes with a micro-USB charging port which should be used for regular charging.
Regardless if You like hiking, trekking, camping, or some other outdoor activity or You want to be prepared for emergencies, Raynic 5000mAh Solar Hand Crank Emergency Radio is a rather versatile unit that is compact, lightweight and comes at an acceptable price.
For more reviews and recommendations, feel free to check the Raynic 5000mAh Solar Hand Crank Emergency Radio Amazon link (link opens in the new window).
Note: Amazon link opens in the new window, feel free to check it for the most up-to-date offers and prices.
Hand Crank Flashlights
Although emergency weather radios feature both flashlight (or flashlights) and hand-crank generators and are rather compact devices, hand-crank flashlights are even smaller and even more optimized for their purpose - some of them don't even have batteries and their storage time is almost indefinitely.
Here are some models that stand out from the rest of them.
Note: one of the most popular squeeze-handle flashlights on the market is not on the list due to the fact that it is advertised as without batteries, but it does come with non-rechargeable batteries that after some time simply die...
Thorfire Hand Crank Solar Powered Rechargeable Flashlight
Thorfire Hand Crank Solar Powered Rechargeable Flashlight is a compact and lightweight hand-crank flashlight that is also designed to be tough and durable.
Thorfire Hand Crank Solar Powered Rechargeable Flashlight features an IPX6 rating - it can be submerged down to 45 feet (~13.7 m).
The unit also features a small, built-in solar panel.
The flashlight features three light modes: medium, high, and strobe.
Only 1 minute of hand cranking is enough for 80 minutes of light with 1 LED, 60 minutes of light with all 3 LEDs, and 110 minutes of flashing.
When there is direct sunlight, 1 hour of direct sunlight is enough for 120 minutes of light or 140 minutes of flashing.
If You are looking for a tough and durable, hand-crank flashlight that also features a small solar panel, consider this unit.
For more reviews and recommendations, feel free to check the Thorfire Hand Crank Solar Powered Rechargeable Flashlight Amazon link (link opens in the new window).
Eton American Red Cross Crank-Powered Clip-On Flashlight & Smartphone Charger
Eton American Red Cross Crank-Powered Clip-On Flashlight & Smartphone Charger is a very popular hand-crank flashlight that can also be used in emergencies to quickly recharge any USB-charged smartphone to allow the user to make a short call - to recharge smartphones completely, one would have to crank the handle a little bit longer ...
At an average cranking rate, the generator is able to provide ~0.5 Amps - a faster cranking rate increases the output current, but such cranking rate is hard to do continuously over a longer period of time.
The flashlight features three LEDs that provide relatively strong light - on average, it takes one minute of cranking to produce enough energy for ~10 minutes of light.
Physical dimensions of the unit are (W x H x D) 2.25 x 6 x 1.25 inches (5.7 x 15.24 x 3.175 cm) and it weighs ~5 oz (~140 g) and can be easily stored or carried around.
Eton American Red Cross Crank-Powered Clip-On Flashlight & Smartphone Charger is a simple and reliable hand-crank flashlight/USB charger, already used by countless users in day-to-day activities, but also in emergencies.
For more reviews and recommendations, feel free to check the Eton American Red Cross Crank-Powered Clip-On Flashlight & Smartphone Charger Amazon link (link opens in the new window).
Manual Power Generators/Chargers
Manual power generators are hand or foot cranked generators that charge devices or batteries directly - these manual power generators are much stronger than the power generators featured on the weather radios or hand-cranked flashlights and can provide more power over longer periods of time, often depending only on the stamina of the user.
To make these units as universal as possible, they feature several output voltages and hence currents, requiring the users to set the output voltage according to the device being charged.
Huaban Hand Crank Generator
Huaban Hand Crank Generator is a compact and relatively lightweight hand crank generator featuring a telescopic and folding handle, voltage regulator, and a set of various plugs.
Output voltage ranges from 0V to 28V max. with a nominal current of 1.5-2 Amps (3 Amps max.) - user can manually set the output voltage to 3V, 5V, 6V, 9V, 12V, 14V, 16V, 18V, 20V, 24V, and 28V.
Maximum power is ~30 watts, but that also depends on the user and cranking speed - personally, it takes a lot of stamina to provide 20+ watts for a longer period of time using just hands (and this is a hands-only device).
The physical dimensions of the unit are ~4.17 x 2.52 x 1.54 inches (~106 x 64 x 39 mm) and it weighs ~1.06 pounds (~480g).
For more reviews and recommendations, feel free to check the Huaban Hand Crank Generator Amazon link (link opens in the new window).
HYDDNice Manual Hand Crank Generator
HYDDNice Manual Hand Crank Generator features physical dimensions of 6.97 x 4.72 x 3.9 inches (~17.7 x 12 x 10 cm) and it weighs 1.7 pounds (~0.77 kg).
This hand crank generator is still compact and lightweight, but if You intend to carry it in the backpack, its weight will be noticed, especially in the long walks uphill.
But, HYDDNice Manual Hand Crank Generator features maximum output power of 20 watts, two charging USB ports, and two ports with a voltage selector (3V/6.6A, 5V/4A, 6V/3.3A, 9V/2.2A, 12V/1.6A, 15V/1.3A).
Note: before using the USB ports, one has to set the voltage to 5 volts!
HYDDNice Manual Hand Crank Generator can be used for recharging smaller 6V, 12V or even 24V batteries, but have in mind that the charging current is limited.
But, it can recharge USB-charged devices relatively quickly, allowing the users to make one or few phone calls.
For more reviews and recommendations, feel free to check the HYDDNice Manual Hand Crank Generator Amazon link (link opens in the new window).
K-TOR Power Box 50 - 50 Watt Pedal Generator
K-TOR Power Box 50 is a pedal power generator, being able to deliver 50 watts max.
At a cycling rate of 1.5 cycles/second, the unit is able to provide 3 Amps @14V, allowing it to directly charge automotive batteries.
K-TOR Power Box 50 comes with a 12V cigarette lighter adapter port, which can accept various charges and adapters, including USB chargers.
The unit weighs 5 lb. 6 oz (~2.43 kg) and can be stored in the boy with physical dimensions of 13 x 9 x 7 inches (~33 x 22.9 x 17.8 cm).
For more reviews and recommendations, feel free to check the K-TOR Power Box 50 Amazon link (link opens in the new window).
Bicycle Power Generators
Bicycle power generators are devices that generate electricity using a rear tire drive - the bicycle is either lifted onto the power generator using a special bike stand, or the generator is attached to the bike with the special bike stand is still being required.
Bicycle power generators may output more watts than hand-cranked power generators over longer periods of time, but they are also larger and more expensive.
Bicycle power generators feature output power in the range of 100-300+ watts - it depends on the cyclist and its strength and stamina.
But, in order to recharge a 12V automotive battery with 10-15Ah within one hour, the cyclist needs to provide at least 140-210 watts (10-15 Amps at ~14V) and that is not the easiest task to do.
Note: 10-15Ah to the modern 55-100Ah automotive/marine/light industrial battery is not much, but again, it is generally more than enough to ensure one proper crank of the engine, after which the engine can recharge the battery via its alternator.
Pedal power generators are able to faster recharge power banks, power stations/solar generators, and similar devices than hand-crank generators.
And best of all, some units feature interchangeable pedals and handles, allowing the users to power such units by feet or by hands.
Hand Crank Power Generators Frequently Asked Questions (FAQ)
Here are some of the most common Frequently Asked Questions about hand-crank power generators, USB chargers, flashlights, and similar devices:
How much power can you generate with a hand crank?
Hand crank generator can provide up to 15-20 watts for short periods of time and up to 10-15 watts for longer periods of time.
However, in emergencies, when there is a need to, for example, recharge a car jump starter, one can provide 15-20 minutes for a long enough time to recharge the required device to be able to reliably crank the engine.
How efficient is a hand crank generator?
Who cares? In emergencies and when one is in trouble, one uses what is at hand. Having a hand crank weather radio ensures contact with the outside world, flashlight, and USB charger, helping the user endure for a longer period of time until help arrives.
Can an electric motor run a generator to power itself? Is it possible to make a free energy generator?
No, Perpetuum mobile is not possible, not even if one uses an ideal electric motor to power an ideal generator using zero resistance wires :)
Will spinning an electric motor generate electricity?
It depends on what kind of electric motor - for example, DC motors are optimized for use as "motors", but they can be used to produce electricity as well.
How can I generate electricity at home for free?
The simplest and the safest way to generate electricity at home is to put solar panels on the roof and to connect them via a solar charge controller (and a few more components) to the home electric system.
Note: although such solar panels can be found even in the form of DIY kits, it is highly recommended to contact certified professionals about this topic and let them install solar panels and the rest of the system for You.
Also, solar panels can be combined with wind turbines. And if You are serious about powering your home during blackouts, consider a good power station/solar generator combined with a home power generator.
Few Final Words
Hand crank power generators can be used as a source of energy for smaller devices and gadgets like weather radios, smartphones, flashlights, and similar.
If You intend to recharge a car's or boat's battery using a manual hand-crank generator, be aware that it takes time to revive a deeply discharged car/boat/truck battery.
Charging the battery with just 1 Amp requires at least a 15W hand-crank generator.
However, thanks to the surface charge of lead-acid batteries, it is often enough to recharge the lead-acid battery with just 5-10Ah for the battery to be able to crank the engine - ones. If You are lucky enough.
Again and again, if You have a lithium car battery jump starter that can be used as a power bank and flashlight, don't discharge it completely, just in case - actually, don't discharge it below 60-70%, or don't use it at all for other purposes but jump-starting the car or boat.
But, it is much easier to recharge the battery of the car battery jump starter than the main car's battery.
Personally, if You are serious about having energy in emergencies and You don't want to spend thousands on roof solar panels (which can be damaged by strong wind and debris), consider:
- solar generator (power station) with few foldable solar panels,
- compact USB solar charger with foldable solar panels,
- hand crank weather radio,
- car jump starter that doubles as flashlight and USB power bank, and
- USB power bank, preferably with the built-in solar panel.
All these devices can be combined in one way or another to allow the user to recharge the smartphone, tablet, flashlight and if the power station is strong enough, to make coffee, tea or to warm up some meal using a microwave oven, coffee maker, or some similar kitchen appliance.
In emergencies and blackouts, it is very important to think out of the box, but it is much easier to think while having a few devices that can help You think while having a warm beverage or meal ...
Whatever You do, stay safe!