Manual rechargeable light

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1

Hi, fellow flashlight enthusiasts!

With the strange times that are ahead of us, I’m looking into “prepping” a bit. Not very extensively, but I would like to be prepared for a moment I’m hoping will never come.
To do so, I’m going to buy a radio that is manually rechargeable, as well as a radiation meter, and last but not least, one or more practical flashlights that can be recharged manually when the power grid goes down for an extensive amount of time.

For this flashlight:

  • What do I look for? Brands/keywords I can search for?
  • Any reviews on the forum?
  • What are your suggestions?

Thanks!
Bart

2

What do you mean my manually? Like mechanical wind up mechanism?

For a low drain device such as a radio, a crank generator system is tolerable.

For a flashlight, assuming you want decent levels of light and runtime, you’ll spend a lot of time cranking, which will consume your time and energy.

There is also a question of durability- the wind up mechanism is a potential source of failure, a couple of regular flashlights and some chargers would help with redundancy.

My solution would be one or more small solar panels and a battery charger with USB input; set them up in a safe place and let the sun do the work for you.

You could also put together a larger solar system if you have space, using domestic solar panels, a charge controller and Pb-acid or lithium battery bank. An inverter would allow you to run small mains devices from your big battery.

For individual cells for flashlights, lithium ion is slightly more “efficient” at charging than NiMh, so stick to Lithium ion cells where possible, but often you’ll need some NiMH cells for other gadgets, there are “universal” or “multi-chemistry” chargers available that will charge both kinds.

This website is slightly dated but is good for comparing various chargers

3 Thanks
3

Thanks for your reply Gravelmonkey!
I am indeed talking about a mechanical wind up mechanism. It used to exist (I had it as a child) even with a filament lightbulb, so I figured there should be a much better system available now with LEDs and better materials/technology. We called this (in dutch:) “een knijpkat” which means “a squeezecat”. It was also used during WW2.
Google: knijpkat - Google Search
I do see that this still exists, but they all look like toys for children and not really for normal use, so I was wondering if someone knew a brand that sells a decent version of this.

I will look into portable/emergency solar panels together with power banks also! Thanks for the tip!

Kind regards,
Bart
TDS

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4

Texenergy infinite orbit does 10W (5V 2A). This is similar or lower than a regular phone charger, except you can’t do other tasks while you’re charging, as youve got to crank the handle… If you’ve a 5000mah capacity battery at 3.7V nominal, then you need 18.5Wh to charge it, that’s 1.85h of cranking the charger.
I personally wouldn’t be able to fully charge my phone in such a way :sweat_smile:.

I concede that in winter, solar is more difficult.

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5

Fenix e-star does exist.

Though when you do the math it turns out single 21700 will give you multiple days of light at the same brightness continuous cranking would. And there is no guarantee that mechanism will even last that long.

It is quite obvious even if you look at runtimes with ni-mh cell the same light has.

IMO - it does have its appeal, but practically - a bunch of cells + a way to recharge them is the way to go.

May be take a look at one of those “power stations” (which are basically huge powerbanks with inverters) + appropriate solar panel(s). That should supply you with power for all reasonable needs up to running a laptop or even a fridge if you opt for larger one.

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6

Have a pleasant time at this friendly forum, Sodomorrah!

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7

You could make a DYI generator.

or something like

81DIeSuWoSL.AC_SL1500
81DIeSuWoSL.AC_SL15001489×1500 175 KB

https://www.amazon.com/dp/B076Q22STW/ref=sspa_dk_detail_1?psc=1&pf_rd_p=0d1092dc-81bb-493f-8769-d5c802257e94&pf_rd_r=0234N7B6X545GXS7MDBF&pd_rd_wg=ChxI6&pd_rd_w=0Co35&content-id=amzn1.sym.0d1092dc-81bb-493f-8769-d5c802257e94&pd_rd_r=213a7bc1-08f5-4d86-8170-1d0429b86ee6&s=lawn-garden&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWwy

And theses sorts of things are all over Amazon.
https://www.amazon.com/12000mAh-Emergency-Portable-Charging-Flashlight/dp/B0CCJTSS15/ref=sr_1_7?crid=2C0GLXE6C5WG7&dib=eyJ2IjoiMSJ9.ome4ObyUZA0Fyl_2D9JA8yrXhWw5miWBEcVauGlatvxFFkAm-eyCboZqWwgdmNaxUB20wd6RuUwpJrZPOtyNhTc0IQtsDv2xvlJaYYphH7hTlo3OlOETNHfS_E_60tB59SZv5oDv5JCOLhB9tS680yXKP54wzmGmL95ygxDJkV4jErfWVkjNQd_6cVGAF8gj8y5P1_erMzK2eKPHfW0saK6cwwJmZxHQiWDNMJFQ_VE.0Yx3pBgpdSiW0bRY3THI6cTeYk4ZN_FGSmfB1jkP7_Q&dib_tag=se&keywords=hand+crank+radio+flashlight+cell+phone+charger&qid=1708881154&sprefix=hand+crank%2Caps%2C141&sr=8-7-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9tdGY&psc=1

71wpL53VPHL.AC_SL1500
71wpL53VPHL.AC_SL15001500×1498 188 KB

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8

Didn’t someone just post on amazon deals about some cranky-light? 10bux, “price of a cup of coffee”, something like that?

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Rotate the handle at a speed 1.5-2 circle per second to get a stable output current

Awesome! That is super fast and you have to maintain it for hours to charge a flashlight. :rofl:

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Thanks Raccoon,
I’ve been on here for some time already though. Just not a frequent poster ;-).

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11

Ah, the Fenix e-star is exactly what I need.
It’s a bit high in price though, but it’s a “knijpkat” from back in the days.
Advantages of the knijpkat are that you can do it onehanded.
It shouldn’t provide hours of runtime, but if you need a little bit of light, it will work for what it’s meant to be!

The cranking mechanism works also, but seems unmanageable since you require 2 hands to operate it.

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Oh, you’re right.
My bad. :smile:

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You might be better off looking at a dedicated USB charger that can produce power from a mechanical device (sometimes as a combination device with solar and a powerbank) as it’ll be more efficient and effective than doing the conversion with a small mechanism in the light itself, then either some lights with USB charging, or a USB-powered li-ion battery charger.

For a geiger counter, for casual non-extreme-environment use, I’d suggest the GQ GMC 500+/600+. Affordable with good accuracy, and also powered by an 18650 which you probably already have spares for lights.

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14

Which doesn’t mean I don’t appreciate the thoughtful Alicia Silverstone pic :wink: !

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Thanks for the suggestions Wolfgirl!
I don’t think I want to go that far into the prepping to have a dedicated USB charger with a mechanical crank or such. The thought is just to have a simple small light that isn’t dependent on the power grid. The Fenix E-star seems to fit the description to this.

Great ID on the Geiger counter! 18650 is indeed available in the house and very standard by now so this one is worth looking deeper into. It’s hard to know which ones are accurate and which ones are just a scam …

How do you know this one has a good accuracy?

Thanks!

16

I’d probably consider that less hardcore prepping than a geiger counter :stuck_out_tongue: (I own mine more because I’m just interested in tech and in measuring things more than for prepping reasons out of genuine belief I need one because a radiation event is likely - obviously, wasn’t not considered, but I justified it to myself as “because it’s interesting”, e.g. I’ve brought it on flights and to an x-ray appointment to measure there out of interest) - Amazon have some reasonable looking combination crank/solar/powerbank devices in the $30-50 range. If you’re looking into prepping on the cheap in general, you can sometimes find solar panels that tested low enough to be rejected for their intended use at a fairly steep discount, then a cheap DC-DC converter and you can run USB devices off those.

If you have no power and no charged devices, what else are you going to do for fun? :stuck_out_tongue:

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17

Dose rate is (basically) a measurement of radiation absorbed into a human.

Don’t look at the dose rate number, it’s more than likely to be incorrect, this applies to moderately expensive Geiger counters too.

Most Geiger counters have a Geiger Muller tube inside that registers the interaction of an ionising particle. The most common types only detect gamma (and maybe some beta).

These interactions are the “click” noise, and devices with a screen will display the number of Counts Per Minute and/or dose rate.

To understand why the dose rate is often wrong, you have to realise that:

  1. Much like the visible light spectrum, radiation has lower and higher energy particles.

  2. The Geiger Muller tube, and associated electronics, can only tell you if a particle has interacted with the tube, it cannot tell you the amount of energy the particle had.

To get a “dose rate” each tube has to have a calibration/fudge factor which “converts” CPM to dose. This essentially means for X number of clicks, you get Y dose… However! The Geiger counter cannot measure energy of these particles!

The fudge factor is often “calibrated” for Cs137- Eg, 2000 CPM is 1uSv, however, 2000 CPM of Sr90 would be a completely different dose.

There are partial workarounds that some manufacturers do, like energy compensation of the tube.

The gold standard* for dose measurements, is a scintillation based device, this has a very sensitive detector that can measure the energy of a radioactive particle. These are always much more expensive than regular Geiger counters. Better Geiger is an example of a scintillation detector, it seems quite low priced for what it claims to be offering.

The above does not mean a Geiger counter is not good for your uses if you’re just looking for go/no-go results. Play with it around the house, see what kind of CPM you get, and write it down. Few clicks = okay, many many clicks = less good.

Because people always ask about contamination monitering: You will only be able to measure radiation contamination of food/drink using a lead-shielded, home-lab, gamma spectroscopy set-up, and the knowledge of how to use it.

*Or film badge dosimetry which is unaffected by electronic fields

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18

And check those nuculer bananas!

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Mostly reviews, although if you are really interested to measure yours, you can buy test sources (usually a piece of uranium ore) with a known activity.

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Unlikely to pick up the banana signal with a simple GM counter. Maybe with lead shielding to remove background, and a lot of bananas?

I’ve a couple of Geiger counters (for fun/interest rather than the apocalypse) and I’ve never been able to detect banana radiation.

Granite worktops on the other hand, oh yes, background count doubles, even on my smallest tube (eBay kit built with SBT-11A).

Highest radiation I’ve measured thus far was in a piece of stone wall made out of waste from an old mine in Cornwall. Think I worked out that if you strapped it to the side of your head, it would be the equivalent of getting a dental x-ray every other day… Not insignificant!

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