30Q suddenly died

I have over discharged my 18650 batteries below 2.5v and manage to get it back alive with charger liitokala 500.

I don’t recommend over discharged but it happened

:slight_smile:

many cells nowadays spec capacity down to 2.5v and a few down to 2.0.
your 30q is probably fine.
but the light has an issue if it drains a cell that low.
vf of the led stops them from draining much lower than around 2.5v.
btw that 60ma charger is probably the safest way to revive a low cell.let it charge till it goes above 3v and charge as usual.

I’ve noted on here before that I have had countless bad 30q cells. They will be sitting for a month or so after a charge or two and then… nothing. .35v or 0v. They usually, not always with awaken when first connected to a direct voltage or another cell but will have very poor performance. I first noticed this after buying 40 cells back in 2016. Of those cells, 12 of them are dead, 10 of them perform poorly and the rest of them are with other people unfortionately. I’ve had them quit on me along the way as well. Just this month I threw away 2 cells. I think there are much more fake cells out there than we realize. I stop buying 30qs even though the flash sale prices are very tempting. If I did buy them I would start marking and tracking them close.

I’d suspect clone cells on those 30Q’s, Samsung is a top brand and you should be able to expect much better than that. I’m not sure how many 30Q’s I have but it has to be up there close that 40 and none have given me any issue, especially considering I run a lot of my 30Q in top shelf hard hitting lights.

LightRider do you 30Q perform like they should in capacity and high drain applications ?

No counterfeit will give you anywhere close to 3000mAh at or above 10A load, they probably won’t even give you close to 3000mAh at any load.

The 30Q are also known to be among the toughest, best abuse surviving cells one can get.

Sound like fakes to me. I have had/still have 20 to 25 30Q and have not had One issue. Most have been in use and the ones in storage were charged up and have worked fine.

No, they do not preform well. If charged or discharged at .5 Amps or above capacity is between 2200& 2400. Slow charge or discharge they will reach 2600.

I’ve bought a lot of 30q over the past couple years whenever they hit bottoms price. From gb bg & aliexpress. Mostly gearbest though. I have and many underperforming or bad cells during this time. The 9 cells from aliexpress, they had a sale for 3pcs set back in January of this year, were all fake/rewrapped/duds/underperforming/bad or whatever you want to call them. They were my go to cell but I’m staying away now.

Why don’t you order from a reputable dealer in the USA? Guaranteed my hometown dealer has real ones. I have been buying my 30Q off of him for a few years.He has a good reputation and great customer service. A group Buy set up by Robert B. was done last June.

This is for BT’s he also has FT’s. They are ONLY $5 and you will know that they are genuine.

So you order all your shit from USA???

I don’t order shit. I get genuine and quality merchandise.

never mind

Oh well, I remember FT used to sell pink Samsung INR18650-30Q printed on shrink-wraps before….( I just checked and they are gone at the moment)

Have bought about two dozen 30Q’s from both BG and GB. Flat-top and button-top. Never had any problems.

For 1S charging I can't see anything at all wrong with a "dumb" charger. By "charger" I assume it's something current limited. So long as it's also voltage limited to 4.2V then you're 100% all set. A time cuttoff (wall timer) wouldn't hurt, but leaving it on for 12 hours won't hurt anything, and I'm unconvinced that even a couple of days will. I use my current and voltage limited supply to charge batteries with no problem.

I particularly like that little ~2buk one at FT. Forgot the current output, only a coupla hunnert mA tops, so overnight is no problem.

Wanted to keep a LK-100B with me in my bag, but that one (AC) or one of the small Thorfire/Sofirn chargers (USB) are lots more compact.

Today I had the same thing happen with my Convoy C8 (old 2-group driver). Bought it last year, not heavily used.

So it was in MED mode, and suddenly stopped working, no LVP blinking at all.

The cell was checked below 1.0V… an old laptop pull, but was working fine before that.

So I tried another fully charged cell. LVP kicked in at 3.6V. Strange. Then I put the light off and on again. Next LVP blink came at ~3.3V.

At that point I verified the C8 and tightened the driver retaining ring (was not loose but I could tighten it a bit).

Now testing with another cell to see a difference. Maybe the driver is toast? :open_mouth:

It sounds like the LVP is working as the you said by verifying with the 3.6 and 3.3 V reading. What you are not allowing for is the voltage drop of the battery under load which is with the torch turned on.
Your batteries may well be past there use by date.

But the LVP is supposed to come at 2.9-3.1V according to Convoy specs.

An older cell would do that?

Looks like an occasion to put a more reliable driver in this one :stuck_out_tongue:

An old cell with a resting voltage of 3.6v or 3.3v, might very easily drop to 2.9v when you put a big load on it (like a Convoy on max).

Most cells don’t have much energy left in them by the time they’re down to 3.3v resting. I usually charge mine up when they get down to 3.7v, which is usually under 50% full. On a light that doesn’t use a boost-driver (such as a Convoy), it also really helps to have a mostly-full battery to get full output.

Thanks for the explanations. I will also make sure to check my cells before use in this light.