How safe are 18650 power banks?

Timothybil

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I am assuming that is the guts of a single cell power bank. Almost all of the possible problems that could arise with any power bank are related to the cells used, although the workmanship and circuit design also play a factor. The cheaper the cell used, and the poorer the design of the circuitry, the higher the risk of problems with the bank. Most of any problems that show up are going to be in output not reaching the claimed specs, and poor life time of the cells. I don't recall ever hearing about a power bank exploding or melting down, but I am sure some have.

From the looks of your photo, you get to provide the Li-Ion cell, which would mean that you would control the capacity of the power bank and the quality of the cell used. In a sealed unit, where the manufacturer controls the cell selection, one had to use some common sense in believing claims of capacity and safety. As an example, a small bank the can only contain at most two cells can not be reasonably expected to provide more than around 7000mAh of capacity, and given the cost of the cells necessary to reach that quantity, 5000mAh would be a more reasonable figure. Any claims for more capacity than could be reached with the assumed number of cell in the bank (mine use three or four, depending on the brand) should be taken with a large shovel of salt.
 

Woods Walker

The Wood is cut, The Bacon is cooked, Now it’s tim
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If you are worried get this:


Nitecore Intellicharge F1 Smart Battery Charger for Li-ion, IMR Batteries

Sorry about the blue text as pasted the name. I have one and the pro being you control the battery which IMHO is the potential issue with any of them. You know the history of the 18650 being used and if there are problems like the battery was overly discharged (the F1 has protection against that) or somehow exposed to whatever just replace the battery.
 

degarb

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If you are worried get this:


Nitecore Intellicharge F1 Smart Battery Charger for Li-ion, IMR Batteries

Sorry about the blue text as pasted the name. I have one and the pro being you control the battery which IMHO is the potential issue with any of them. You know the history of the 18650 being used and if there are problems like the battery was overly discharged (the F1 has protection against that) or somehow exposed to whatever just replace the battery.


I like that this nightcore (or 'nightmare', as my phone spell correction keeps auto replacing) is abs and can charge cell phone and internal. . Abs, being very lightweight and fire retardant. . I will need to look into or test this fire claim myself. I am interested in thin, light 18650 flame shielding - from my phone to my 12 hour running headlamps I use daily.

I never went imr as their capacity is so poor. Also think their chief safety selling point is discharge safety and not overcharging safety. . I never will use any light that can go above 350 ma per cell-higher current lights go into the garbage or storage drawer. So, I just use protected name brand Panasonic 3400mah, tested/smart charger that stops at 4.2 volts, and regular dmm volt meter testing off charger. Overcharging is main reason for explosions. . Fake protection circuits too. . Though I plan to build a one handed cell volt tester, since dmm testing takes 3 hands and often daily time constraints means skipping this step.


Also, why is this nightcore marketed as the first outdoor charger? Waterproofing is good, especially where heat dissipation and weight aren't compromised. . My homemade headlamp bezel that secures the reflector is open air, so I get airflow around aluminum reflector, the inside bezel metal, airflow on mcpcb of led. . I do thermal epoxy to waterproof my electrical connections and to keep the reflector and ar glass air tight.... My moto g4 claims a nanotechnology spray to waterproof the circuit boards, rather than trying to waterproof the case.

My other question for previous response from Timothy bill's cat's cccv board suggestion is, where can you get a charging cc/cv board that doubles as a cell charger?

Feel free to dispute me on my imr overcharging conclusion. . I am interested in the truth. And it is in my interest if I am wrong, as this would mean more battery options, even if the capacity doesnt match my typical cc runtime output spec, yet.
 
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Woods Walker

The Wood is cut, The Bacon is cooked, Now it’s tim
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Cell phone auto correct hates me as well. I think Nitecore markets the F1 as their outdoor charger for a few reasons. First it is very very solar friendly and can both charge and be charged via solar or other power source at the same time. Also it's UL and naturally is both a battery charger and powerbank. I pack it all the time in water proof bag. Remember the Goal Zero Guide 10 (will pack that if using AAs) is also marketed as an outdoor charger despite not being waterproof. So far have maybe 1000 (probably more) foot miles using either one and they survived.
 

degarb

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Akron, Ohio
How do you solar charge?.. So you are telling me this night core is at least moisture resistant?

Though in the real world, for the emergency cell phone charging capability to be reliably present, one needs to locate a 2 to 4 inch micro usb ribbon (out to cellphone) that can be stuffed into a wallet and be forgotten.

My thinking, if I bought this nightcore, is not to unmodify. Rather epoxy a heatsink: http://www.jameco.com/z/630-160-TO-...OAcW4NDjpwrW2iPoprtr-tnSpLR2kmrWzQaAqG-8P8HAQ (bezel), a v6 xpl, a single amc7135, a 555 circuit for infinite control, and rig it up to 3 strap headband. Probably shoot for 4k candela at one watt for my reflector choice. 4k gets me 1k at 2 meters which is minimal lux for inspection. 350 ma is highest current allowed for a full workday, while often might only need 280 or whatever your cc pot can offer. Keep it to 90 grams and it will be as lightweight as a Convoy, can be wound around belt loops, under a nail apron to be forgotten until emergency, and get 3 to 6x runtime of a Convoy with ample closeup and 2x distance of its 800ma mid-level. And zebra style head is more comfortable to wear. ... Though will need to consider abs gluing techniques, rain drop resistance, and price tag of nightcore.
 
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