I just read that 18650 cells are dangerous. What is your experience with this? What do you recommend?

I've noticed that there are some very cheap, bright flashlights that run on 18650s or 26650s. Is this always the case? If so, how is the run-time between cell replacment or recharge?

I am thinking about getting an inexpensive Ultrafire Wf 502b Cree Xml T6 3 Mode Cree Led Flashlight 900 Lumens and some Ultrafire Li-ion 18650 3000mah Batteries. I didn't decide on a charger yet.

I'm a little reluctant to make this switch because I already purchased an Energizer charger and 12 AAA Energizer rechargeables for my tail light and coleman flashlight.

A friend bought this one: Total package, light, mount, battery, and charger, free shipping.

Mine runs bright for 3 hours then I change the battery. ( I have three of the 18650 lights)

I have been using the batteries for 3 months no problems

Super Bright Road light with adjustable beam.

Super Bright Strobe for Daytime Safety.

I saw it the other night from 1/2 mile away.

https://www.tmart.com/Q5-3-Mode-LED-B...0_p124037.html

What I like best about 18650's over AA's is that the 18650 batteries hold their charge for weeks or months but the AA's won't hold their charge.

Li Ion batteries pack a lot of power. Yes, they can be dangerous. Checkout https://www.batteryuniversity.com. Check out Candlepower Forums. Check out https://www.budgetlightforum.net. You'll find plenty of information about battery safety.

#1: Multiple battery devices take more battery care. I avoid them. This doesn't include battery packs for Magicshines, but flashlights were the user selects batteries to use.

#2: Batteries should not be charged while unattended and they should be removed from the charger as soon as charging is complete. I apply this rule to all chargers including expensive ones. I don't leave my laptop plugged in at home unattended, either. Charge in an area that isn't flammable (carpet burns easily).

There are plenty of posts on what flashlight should I buy. https://www.mtbr.com has a forum where people talk about cheap lights. So I won't make any suggestions other than to read forums and just buy a single 18650 XM-L flashlight. I find 26650 lights too large for my personal taste. YMMV.

For $100, you should be able to purchase batteries, charger, two lights (one for bars, one for helmet). There's not much out there for rear lights that take 18650 batteries.

Hope this helps.

18650 is a battery FORMAT. Its not actually the format thats dangerous, its the chemistry and the same hi-power lithium chemistry is available in a variety of formats. Their main advantage is their ability to support a larger current draw than Alcaline or NiMH or NiCad.

The newer rechargeable AA batteries self discharge much more slowly and will hold a charge for months.

Avoid Ultrafire like the plague!
Here is why: https://www.torchythebatteryboy.com/p/batteries_21.html

Almost anything is dangerous is used incorrectly. On the AAA/AA chargers. I got a draw full of them. We all started with the AA/AAA stuff. But, now we have graduated up to the bigger stuff. Simple as that. Just because I have a draw full of AA/AAA chargers, I am not gong to stay with AA/AAA type batteries. I have even moved passed the 18650, I am cruising with the 26650 type lights.. Oh boy...

Another thing I learned while progressing with the bigger cell flashlights. Stay away from the cheap cells. I too have some of the Ultrafire stuff. Ha, I throw them in the lights on my wife's bike. She seldom rides. Cheap cells are a joke. I found that out from experience and reading in the flashlight forums. They TEST the cells in those forums. You find out the good ones and the ones that are crap. Even got some so-called good ones but turn out to be fakes.

The good 18650 cells are going to cost you..I got some Hi Max 2600Mah 18650 cells for $6 each. They have the AW, Panasonic and a lot other quality cells out there. So do your research on that, and used the Utlrafires for starters. Also, learn the dos and don't of handling battery cells, and you be okay nothing to worry about.

Sure they will. Switch to Low Self Discharge NiMH AAs. Eneloops or any of the name brand or house brands that are labelled "pre-charged" - they hold something like 80% of their charge after a year on the shelf.

OP: I have no problems. I use UltraFire protected cells from DX. It's been about 3 years, no problems. I don't use them heavily, mainly my lighting is on an 18650 based pack for the Magicshine light. That I charge twice a week or so. Almost everything I own is now on LiIon of one kind or another. The only time I've had one blow up is when I intentionally shorted one out to see what would happen. It was impressive. I'm going to do it again soon and post the video.

Thanks for this. That looks like the dealextreme charger I've been using for the last few years. I'm going to inspect the insides before I plug it in again.

Top tip, already covered by reference I'm sure... get protected cells.

It seemed like I would have to pay a significant amount of money for decent 18650s and a decent 18650 charger. I'm short on money, so I ordered a temporary (3x AAA) CREE Q5 LED Flashlight Torch for $7.59.
For more money, the same light is available with a bicycle mount, so I read those reviews, which commended the light while condemning the mount it came with. They paid at least $10 more than me, but they still gave it 4.7 stars.

I ordered a nice mount that can hold large flashlights in case I replace one of my flashlgihts later on, but I can still cancel the order if anyone speaks out against it. It's the Biologic FlashmountTM Light Mount from Bike Hugger ($11.99).

Now I will have two flashlights!

The TwoFish Cycle Block has stronger straps, you might want that instead: https://www.boomerdirect.shoppingcart...53/1226129.htm I've broken straps on the lighter-duty variants before.

Are either of these the same thing?
https://www.amazon.com/TwoFish-Lock-B...sr=1-3-catcorr
https://www.amazon.com/Two-Fish-Lock-...7545190&sr=1-1

Those are the light-duty ones that I've broken straps on. The Cycle Block has much, much stronger straps.

Response in your profile.

EDIT: Thanks for finding an alternative shopping site, and the recommendation, of course.

When you say "shorted out" do you mean load it in the charger backwards? Put in the flashlight backwards too??

I am real careful when I load them in the charger. Even though I know where the positive is, I always check and eyeball the plus sign just to be sure!!

I'll get one of these when my cheap charger which I got from dealextreme couple of years ago bites the dust:

https://www.amazon.com/gp/product/B00...R&sn=ORBTRONIC
https://www.amazon.com/Tenergy-2-Chan...ductPromotions

No, I mean I shorted it out. Shorting out has a specific meaning and that's what I mean.

I took the cell apart, removed the protection circuitry, put the thing on the ground behind a shield and remotely shorted the thing out. It got ridiculously hot very fast, smoked and blew. Nothing wrong with that, it's exactly what the cell is going to do. I just had seen all this stuff about what would happen, and decided to try it myself. I do not recommend anyone try this at home.

I'm guessing it depends on the cell build to some extent. I'm running 6.6Ah Lipo 3S batteries that will support a draw of 165A continuous or 330A burst. Either one is probably as close to a short circuit as you can get with any actual load on the battery considering it'll empty the battery in seconds.

On the other hand it'll run 40 W of lights for a few hours.

Sure, but this was 18650 LiIon. Lipo are different. You can short out some chemistries without damage. LiIon is not one of them.

I hope you are right. I just bought some name-brand AA's from Walmart and they are labeled "pre-charged". I use them for my Dinotte 200L.

I did not use low self discharge cells in my Dinotte because I dropped the NiMH into the light straight out of the charger, so self discharge never was an issue anyway. No reason they shouldn't work though.

The funny thing is, the only difference between normal and LSD NiHH is a wrap of blotter paper soaked in de-ionized water wrapped around one electrode. Probably costs a tenth of a cent, but they sure charge for it at retail.

It was my understanding that its mostly just the packaging thats different. An 18650 is a particular 3.7V polymer Li-Ion cylindrical single cell format and what I'm using is an 11.1V power pack comprised of three 3.7V polymer Li-Ion cells linked together. What am I missing?

Is the rubber block itself any different from the cheap ones? How did you manage to break the straps on the cheaper ones?

Lithium polymer uses a crystalline (salt form) electrolyte which still should not be subject to direct shorts, it's very bad for them, though I suppose if that's what it's designed for maybe it's OK. In any case I don't think the electrolyte in a LiPo battery will boil like it will with LiIon. I dunno, I haven't tried shorting LiPo cells. Maybe this summer I'll grab a few cheap cell phone batteries, remove the protection circuits and see what they do. From the Youtube vids I've seen though, basically they get hot, swell up, the plastic container pops and steam comes out.