Cheap 18650 Power bank battery & XML T6, Dangerous?

I have a 18650 battery from a cheap "rectangular" Chinese Power Bank, unbranded (blue...). On the powerbank case it says Capacity: 1200mAh, Output: 5v-1000mA.


I have a Q5 flashlight and it works great in it, but I recently bought a T6 and I'm afraid it could be dangerous since it's a 10W chip and works at current of 3A, obviously the 18650 is unprotected.


I have recycled batteries from an old vaio too, not in great shape, so I don't know what's worse.

Why risk it. Good 18650 batteries are relatively cheap.

Woods Walker said:

Why risk it. Good 18650 batteries are relatively cheap.

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+1 on this. No name Chinese 18650s often are overrated such that your battery may not even be a good as rated and on a 3A load you aren't going to get decent runtime at all for two reasons: Lack of capacity and internal resistance may limit performance, heat up the battery in use wasting power that could be used to light the LED. What you need is a 2000mah or greater 18650 of known performance.

Cheap batteries from dubious sources are the cause of mishaps, fires, injury, and property damage. My advice is to purchase quality cells from reputable dealers only. First rate batteries are cheap enough that it should not be an issue for anyone.

Woods Walker said:

Why risk it. Good 18650 batteries are relatively cheap.

Click to expand...

Lynx_Arc said:

+1 on this. No name Chinese 18650s often are overrated such that your battery may not even be a good as rated and on a 3A load you aren't going to get decent runtime at all for two reasons: Lack of capacity and internal resistance may limit performance, heat up the battery in use wasting power that could be used to light the LED. What you need is a 2000mAh or greater 18650 of known performance.

Click to expand...

Modernflame said:

Cheap batteries from dubious sources are the cause of mishaps, fires, injury, and property damage. My advice is to purchase quality cells from reputable dealers only. First rate batteries are cheap enough that it should not be an issue for anyone.

Click to expand...

Thanks. I now there is a lot of info, but when you say relatively cheap you mean like 4$?

The 18650 itself is not rated, there is nothing printed on the battery. I guess it's dangerous because if it's not rated for 3A, bad things can happen, and I guess there is no way to tell, only compare the light it produces with a better battery and see if it heats up. So I will not use the Chinese one to be safe. But it should be safe to try just for a second to compare brightness between batteries right?


The laptop batteries are "SANYO R2112" light Green tip, if I divide the battery pack specs they should have 1750mhA, but I could not confirm the model, by the light Green tip are supposed to be UR18650Y with Min/nominal Capacity: 1900mAh and Typical capacity: 2000mAh with 2.0CA = 3.80A
I don't know if it's usual to rate the battery pack with less Wh than you get multiplying each battery (I think it is because it happened the same with an hp pack that I discarded, dividing they where 2460mAh but the batteries where 2600mAh), or this is not the model, visually they look the same.

I disassembled the battery pack today (charged), all batteries are 3.86-3.92v, and the laptop only lasted less than 5min on battery, so I will see this next days the condition they have, looking for voltage drop, max volts after charging them individually, heat (I know some of them heat up) etc. I will follow the "recycling tutorial". If any of the 6 batteries is good it must work well for the T6. (The laptop was a 35W CPU + 15W dedicated graphics card + screen, hdd, etc so each one must be good for 10W at a continuous rate).

Yes. There are some good options in the 4-5 dollar range. Here is a dealer I use.

http://www.illumn.com/batteries-cha...rs.html?___store=default&battery_size=292&p=3

edit.

What might really make those batteries a potential risk IMHO is you don't know their history etc etc etc. They could have been critically over discharged or otherwise abused.

There are a number of bad things that can happen with inferior cells. I once decided to disassemble a cheap battery I bought with the name that is universally accepted as the most commonly counterfeited cell around(this was years ago when I knew very little and had not heard of CPF). As I removed just the covering wrapper, the cell ignited with fire, causing me to drop it on my shorts at which time it vented, shooting it about 7 feet across the room. After I disposed of it & ventilated the room to remove the poisonous gases released I finally noticed the two burn marks on my shorts and came to realize how close certain body parts that I am very fond of came to become "fried". In my case, that became motivation to learn what went wrong & how to avoid it(hint #1, as above, only buy quality cells from reputable buyers). Soon after this, I read a report of a man who had a two cell Surefire explode-he claimed it was defective (I wondered, because of Surefire's reputation of excellence)....come to find out he had one nearly dead cell and one brand new cell. This was an epiphany for me because all my life I ignored every warning not to mix new and old, or different brand batteries. I figured that was just a way to get us to buy more batteries. I had never had a problem. It up to that point I never owned a single Lithium ion battery. Lesson learned. As I became educated, I grew to the point I trusted more than just AW batteries and Surefire batteries. I understand the appeal of free or cheap batteries from laptops or other devices-but if they are not good enough for their intended use, why risk it? There have been 2 or 3 members who have taken commercially intended clusters of 18650's, disassembled them & sold on CPF(eBay is tempting, but there are too many counterfeits to justify the risk ). One of these is Beastmaster, I have bought 30 or 40 batteries from him-he tells you the battery brand, specifications and this info has been proven accurate time and again. He charges $3 per cell. There are numerous other sellers as well, and a wealth of info. I apologize for the length of my response but wanted to share my experience when I thought "what could happen, I'm just taking the wrapper off", kind of like "it should be safe to try for just a second to compare". Please understand I in no way say that to make fun or belittle you in any way. It may be ok, but if it isn't, you in effect have a pipe bomb in your hand. Please note how all of the responses from members of CPF are so similar in their responses-we truly care, speaking for myself, I don't want to see another post about injuries from batteries, and yet they are occurring with more & more frequency. I'll even put my money where my mouth is: if finances are an issue, pm me your info & I will mail you a new 18650 to meet your specs in less than 24 hours....

ledpanel said:

Thanks. I now there is a lot of info, but when you say relatively cheap you mean like 4$?

The 18650 itself is not rated, there is nothing printed on the battery. I guess it's dangerous because if it's not rated for 3A, bad things can happen, and I guess there is no way to tell, only compare the light it produces with a better battery and see if it heats up. So I will not use the Chinese one to be safe. But it should be safe to try just for a second to compare brightness between batteries right?


The laptop batteries are "SANYO R2112" light Green tip, if I divide the battery pack specs they should have 1750mhA, but I could not confirm the model, by the light Green tip are supposed to be UR18650Y with Min/nominal Capacity: 1900mAh and Typical capacity: 2000mAh with 2.0CA = 3.80A
I don't know if it's usual to rate the battery pack with less Wh than you get multiplying each battery (I think it is because it happened the same with an hp pack that I discarded, dividing they where 2460mAh but the batteries where 2600mAh), or this is not the model, visually they look the same.

I disassembled the battery pack today (charged), all batteries are 3.86-3.92v, and the laptop only lasted less than 5min on battery, so I will see this next days the condition they have, looking for voltage drop, max volts after charging them individually, heat (I know some of them heat up) etc. I will follow the "recycling tutorial". If any of the 6 batteries is good it must work well for the T6. (The laptop was a 35W CPU + 15W dedicated graphics card + screen, hdd, etc so each one must be good for 10W at a continuous rate).

Click to expand...

Typically lower capacity good quality 18650 batteries have lower internal resistance and are capable of higher currents but it is not a given thing. I believe the Sanyo R2112 are good to about 4A current. If you have a charger/tester that can give you capacity some also measure resistance too. Often laptop batteries fail because one set of cells (in parallel) go bad the other sets can often be ok. My advice when dealing with laptop pulls is monitor charging of them and in use the first few times to make sure there is no issues as I've had some that were marginal that ended up after 2-3 cycles falling in capacity and heating up in the charger too much the rest of my pulls after 4-5 cycles have not experienced any issues. A clue to how "good" cells are in a pack is once you pull out the bad cells compare the tested capacity of all cells and if they vary a lot (more than 10-15%) they may go weak in the future in use.
I don't have any 3A lights only cheap lights 1A or less and power banks and a 18650 powered fan for mine.

Make sure on laptop pulls to mark individual cells and keep stats of them and test them when either they get abnormally warm or seem to be less in runtime than expected. I've tossed over 2 dozen bad batteries away (recycled) after I drained them to where they wouldn't put out even 100ma current under a dead short.