Fandyfire Queen Battery Drain

I just received my Fandyfire Queen and put in 3 fully charged 16340 batteries. I played with it for several minutes and then put it down. Several hours later the flashlight won’t turn on. I check the batteries and one of them are drained to zero. The other two batteries are badly drained. I’m experiencing severe parasitic drain.

I recharge another set of batteries - all measured to 3.45v. I leave them in the flashlight for 5min without turning it on. I measure the batteries and they lost 0.14v. I put the batteries back into the flashlight for another 15min and remeasured their voltage. They lost another 0.40v. Another 5min and another 0.16v gone.

This flashlight has to be a malfunctioning but I’ve read that the Rook has a similar problem. How can this flashlight be so poorly designed or pass inspection? Has anyone else experienced this issue?

Thanks

cjoe

Are those batteries reliable? None the less, if a battery was drain to 0, I would not use it anymore (unless it's the protection system that kicked in and the battery it's 0.00V).

3.45V is not a charged voltage that it close to discharge when the battery would be put on high current load.

Does that flashlight have electronic switch? if not, then the batteries are bad (or the protection circuit of them)

I quickly recharged a second set of batteries using a cheap dual charger because my regular charger died. I’m waiting for another hobby charger to arrive. The initial set was charged the previous week to 3.8v. They were discharged in a couple of hours in the Queen. The same type of batteries charged the previous week are also in several other small flashlights. I just measured them at 3.8v no drain.

Do 16340 have the similar characteristics of 18650 in terms of under voltage <3V damaging the cell. I’ve tossed the first set of batteries already.

I’ve never seen such a huge drain issue before.

cjoe

They should be 4.20V fully charged. If the cells are discharged under 3V they are not damaged. They need to go lower for them to be damaged quickly.

Which cells do you have? Do they have a protection circuit, the ones that are 0V?

Yes, they are the protected Trustfire 16340 880mah 3.7v. There were working fine for months. I have read on other threads that protected circuitry will not stop the drain effect.

I put one of the second set drained (3.38v) batteries into a single 16340 flashlight for 15min without turning it on. After 15min, its still 3.38v. No drain. I retrieved one of first set of badly drained (<2v) batteries and put it into a single 16340 flashlight. It turned on momentarily and cut off due to the protection circuit. So the protection circuit works but it doesn’t stop the drain effect.

cjoe

Yes, but it doesn’t light up like the my Nitecore TM15. According to another CPF member, his Fandyfire Rook also drained a set of eneloops within 3 days. He wasn’t clear whether it worked the previous two days prior or he just checked it on the third day. According to some other threads that I’ve read, the parasitic drain will continue even with the protection circuit.

The batteries are the Trustfire 16340 880mah flames from DX. These batteries were working fine in the small single cell flashlights. The batteries are holding their voltage outside the Queen.

cjoe

Now there's something interesting, if that cell was 0.00V it may very well mean the protection circuit kicked in and if you would put it back in the charger for 2 seconds you would get something else than 0.00V

However the protection circuit seems not to work if the other two were drained down to under 2V. Now if the protection kicks in under 2V ("I retrieved one of first set of badly drained (<2v) batteries and put it into a single 16340 flashlight. It turned on momentarily and cut off due to the protection circuit.") that is not much of a protection.

Try measuring your Queen's parasitic drain using only one cell.

I have put fully charged batteries in my Rook and Queen to measure the drain.

I am awaiting the arrival of a Queen from DX. Parasitic drain on the Queen and the Rook is known to exist by the very nature of the light's electronic switch and no thread lockout (no anodization on the threads) but that much drain is completely unacceptable. It's definitely not the fault of your batteries. It's either normal drain from horrible engineering or there is something wrong with your particular example.

I'm looking forward to what How2 sees on his and from what I get from mine. I don't see how they could have made a light with an electronic switch without providing a way to lock out parasitic drain. They should have made it like the King. Pulling out the cells every time you put the light down will get old REAL quick and the light will be resigned to the back of the torch bin.

I just put one battery (initially 2.9v) into the Queen. Within 15min, it was 0v. The protection circuit probably kicked in. My Queen must be really screwed up.

I remeasured the second set of drained batteries after sitting 6hrs in another flashlight and its holding the same voltage. Its not the batteries.

cjoe

Sounds like this isnt parasitic draw, this is a short, parasitic draw would drain them slowly by the very nature of how it works. Send it back under warranty mate

+1

That’s what I’m thinking also. This sucks big time because this is the replacement flashlight for a previous defective Queen that wouldn’t even turn on. I initially ordered this flashlight over 3months ago. Again, I don’t have a working Queen flashlight. Seriously bad luck.

cjoe

I charged the batteries to 4.20v and left them in the flashlight for 10min. When I opened the flashlight, the driver board was hot and the batteries were very warm. The head was warm as if the flashlight was being driven on high mode.

I think they may be shorting from the sounds of it. Have you measured current draw yet?

I can’t take or rather don’t know how to take apart the queen flashlight. Everything is super tight and I don’t want to scratch or damage it further. I still need to RMA it.

Do you know how to take one apart?

Cjoe

Simply remove it so you can replace the batteries and then replace the body of the flashlight with the leads on your DMM.

Parasitic drain for 6 days and 18 hours.

Rook Trustfire Flame 14500 battery 4.2v then 4.07v for all 3 batteries

Queen Trustfire Grey 16340 battery 4.19v then 3.80v for all three batteries.

The Rook is Bad used 1.17volts, while the Queen used 0.39v.

I just measured with one battery. The current draw for high is 1.30A, for low is 0.49A and off is 0.15A. Its definitely a short not just parasitic drain.

I need to buy more tools like several clamps, alligator clips, a better DMM with more leads. It would have been nice to fully replicate the entire circuit.

HOW2’s Rook drained 1.17V and Queen drained 0.38V in 6 days which is better but it would eventually render the batteries useless if not constantly monitored. These flashlights may need to be returned due to poor design.

cjoe