Need help choosing unprotected 18650 for Convoy S5

LED Flashlights – General Info
1

This is my first 18650 light and I need to get some cells for it.

I had ordered some Panasonic NCR18650B Rechargeable 3400mAh thinking the run time would be nice as I wouldn’t have to charge the cells so often (planning on using a ML-102 V5 to charge).

But I read that these high capacity cells are Li-Co, and Li-Mn are safer. So I cancelled my order.

I would rather use these safer cells for peace of mind, but now I don’t know what cells to get. :~ I can only fit unprotected flat top cells in the Convoy S5, which is powering a 3*7135 driver. I don’t know what kind of current draw demands that equates to.

Am I worrying too much? I thought about getting one of these fireproof charging bags but then I won’t be able to see the status LEDs (I also plan to attach a voltmeter).

Should I think about cutting the springs down to fit the longer protected cells, or will that not help as they are wider too?

This is all so complicated, but honestly, after having the S5 in my hand I would much rather carry and use this light than my EA4W which feels bulky and heavy in comparison.

2

What are your concerns regarding these cells? When you have just one cell, it will not blow up in your light. Draining them below 2.7v will only decrease your total uses. Its only in series you need to be cautious to make sure both cells have equal power and be of equal condition.

If you’re really freaked, you can always just swap out cells frequently.

3

Get a 18650 battery holder & connect wire leads to your ML-102. Then you can see the status leds while your battery is inside a lipo bag. Its also good to store your 18650s in a lipo bag.
Some worrying is warranted.

edit
I attach a temperature sensor to the side of my batteries while charging. This would work Compact LCD Thermometer

4

Well, I read some horror stories of venting and fires.

I gathered it’s safer using one cell lights and since I won’t use the light for that long before I can check the voltage it shouldn’t run down too far (I think this driver cuts off at a certain voltage but I am not sure about the recoil light I recently ordered).

But even if I take care measuring during charging and after use, there is the fear of it venting randomly.

5

Ahh, thank you! So do you think it would be okay if I took these precautions, to use Panasonic or Sanyo Li-Co based cells? I could also take the cells out of the lights after use instead of leaving them in like I do with my Ni-MH lights.

6

Probably. :slight_smile:

7

Most likely situations where 2 or more cells in series were used. One cell depleted and the others reverse charged it.

8

The Panasonic 3400mah can be drained to 2.5v safely. I don’t use a fire proof bag or anything while charging. But I do have them very close to me while charging and never leave them unattended just incase. I have seen ads that say the S5 has a low voltage warning, I don’t know if this is the case with yours. If it does you should be fine using it to tell when the battery is running low given the Panasonics can be discharged down to 2.5v, even though most times you will have already charged it before it even happens.
If its piece of mind you want remove the spring on the driver and solder a small blob on there and see if a protected cell will fit. Maybe something shorter might help too. You can look at HKJ site and find out all the different lengths for several quality batteries with pcb’s. Battery test-review 18650 summary
Maybe some Sanyo 2600mah will fit.
.
If it has 3-amc7135’s then it should be a 1000ma version which would give you a run time of a little over 3hrs with the 3400mah. The 2600mah should run a little over 2.5hrs.

9

Better so start out extra cautious.
More people should be as cautious as Chloe. Seriously, you talk to some people using li-ions and its just clear they shouldn’t be anywhere near one. It a risk not only to themselves but anyone they live with. Need to have at least a little respect for the energy they pack into that little metal shell.

What do a couple precautions actually cost?

10

One of the random venting cells was a Panasonic CGR18650CH. Bad timing that this thread started just when I had ordered some cells:
http://www.fasttech.com/forums/1141101/t/1029637/be-careful-exploded-while-not-even-in-use

I can’t remember the other (it was on the other forum) but I know it involved hydrofluoric acid, really awful.

But there are many other unknown factors.

11

Better to be safe than sorry. :_(
Sometimes its not the battery that causes the fire with flames either, charges have been known to go poof too.
Never charge li-ions unattended, you could seriously burn down your house.

12

Yes, you’re right. I was thinking even though the ML-102 can be powered from a netbook I would rather use my 1A USB power supply as I’ve read even spikes etc. may cause problems charging.

It’s a little less convenient but even observing my phone charging with a charger doctor makes me think there might be something to it.

13

Sounds like you would be safer with Li-Co cells then 90% of the people using them.
I mean there are lots of e-cig users are out there now & many stores sell li-ions without informing them of any precautions.

14

Do you put your cell phone in a lipo charging bag? Or you laptop in a lipo charging bag, that uses uses several cells?

Would you fear driving a Tesla Models S, using around 7000 NCR18650 batteries? (Even in crash tests its doing great in terms of battery safety and everything)

Im all for safety, but after reading on BLF on li-ion safety you can easily end up getting a bit paranoid about the safety of li-ion cells in general.

How many thousands of 18650 cells do you think get produced on a daily basis? The very few cases I have heard of causing any damage have used crappy (Ultra)Fire cells, in crappy chargers, and combined with lights using a series-setup and no checking on the batteries.

There have been reports of cell-phones blowing up and such too. Li-ions are not 100% safe. Living, walking out of the house and such are not 100% safe either. Considering the amount of li-ion cells that is around, there is really no need to worry as long as you get some good cells and don't abuse them in any way.

When that is said, I prefer protected cells, because I have managed to run into the protection on some cells a few times (either due to extreme drain, not something you should worry about unless you are doing some extreme current modifications to some lights. Or due to badly designed light,possibility of tail/driver spring and retaining ring connecting to the battery at the same time. Or due to user error when trying something..

3x350mA regulators gives you 1050mA. 1 amp aint much. 18650 cells can do 1amp all day long, at least until they are empty.

Im not sure which cell to recommend you if you are going the unprotected route though. So this reply may not be that helpful, but using a single cell in a flashlight is not much to worry about in general. On top of that the nanjg 105C also have built in low voltage warning, so when using the light there is nothing to worry about, because you will be warned with blinking/dimming. You could end up draining a battery if the light gets accidentally tuned on, but if you have the light in a bag, purse or something. Just unscrew the tailcap or body a little. On most lights that cuts the connection and renders the tailcap useless for accidental activation.

I either stick to protected batteries, or high drain batteries without protection. If I use high drain, I often combine with a Qlite driver or something. That driver cuts off the light when cell voltage gets very low, but first it warns you. :) Its basically idiot proof.

15

I particular don’t like to carry a light in my pocket that doesn’t not have a protection circuit.
I have had a twisty light come on before in my pocket and didn’t even know it, until I felt something getting warm down there. It didn’t catch fire or anything it was just on heating up my leg.
Without a pcb and the drive current being less it could have drained the battery to the place of no return without me even knowing it. I will not EDC a light without a protected battery for that reason.

16

Thanks you all! I feel a bit better now.

I got the Li-Po bag and thermometer and will make some leads with magnets for charging. Unfortunately I don’t think protected cells fit into the Convoy S5 diameter-wise even if I trimmed the springs they won’t fit.

Oh, the Convoy S5 has a firm clicky so I am confident it will not accidentally turn on when it’s in my coat or handbag.

17

I was just going to post that ebay has colored lipo bags, cheaper then FT as well.
Bit late. :~

18

Aww, thanks anyway! There is still time to cancel that item as one of the things in my order won’t be in stock for a few days yet.

19

I’d like to re-recommend the AW IMR 2000mAh 18650. It fits easily and is a much safer chemistry. :slight_smile:

20

Where can I get the AW? I think I would prefer that.

Nevermind, found them* for sale on the other forum.