DBSAR Lantern Mini-Review: -Zanflare T1 (UPDATE: Second T1 failed!

What is PTC protection?
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That is a ring inside the battery that will change to high resistance if it gets too hot, this will basically disconnect the battery. It is not used in all batteries.

You can see it in this tear-down: Disassembly of some UltraFire batteries

This is not true. The T1 battery tube is not sealed. If pressure were to build up, it would go through the positive end of the battery tube, through the pcb and into the white plastic housing. Then the white plastic would break relieving the pressure. So it would not be any kind of pipe bomb if that’s what your thinking.

On flashlights I have seen some pictures where it vents through the driver board and then through the switch hole.

But that wouldn’t address low temperatures and PTC tripping would kill the cell. Sounds like the typical marketing department over hype on nonexistent or features they don’t understand.

KuoH

Is the tube even that thick or is it just a thin piece of sheet metal rolled into a tube with a crimped side? I wouldn’t think they’d waste that much material and add weight by using a thick walled tube like a flashlight.

KuoH

I think the wall thickness of the battery tube is quite thick. Maybe at least 5mm thick. You can tell because there’s a threaded screw hole at the top.

DBSAR, do you have any more pictures of the lights internals or of the plastic part that’s removed?

Must have been a bad battery. I heated a Samsung 25r up in a Emisar D4, installing it backwards testing for reverse polarity protection. It heated up to measure 215ºF on the outside of the battery tube. No telling what the actual temp of the 25r was. By the time I got it apart, the battery was still at 180ºF with no venting. PTC, that HKJ mentioned, may have prevented it from thermal runaway and exploding though.

I think he Vented! :open_mouth:

Whatever breaks after a vent (tube, plastic housing) will break in a way we can’t predict if we don’t test it. Even a flying piece of plastic can be as good as a knife if it hits right, and that is if you are right about the tube having an easy way out for the gases. If a battery vents, it will increase the pressure inside a closed cylinder. So, no, no vent holes = possible pipe bomb.

Also, flashlights do explode from time to time (mobile phones and laptops too), it’s a risk we all take and we can’t be sure that they will vent through the driver board or switch hole or use any other “easy way out”. They are not designed to fail, they have all kinds of protections, and still, they sometimes do. Seems like the T1 works close to the battery fail limits without any thermal protection and I would prefer it not to.

That’s just my opinion and, of course, I could be wrong.

He certainly did, LOL!

“With flames” it appears. :wink:

Gearbest contacted me, but never heard back yet from my reply.

right now for the sample i have I am keeping it limited to roughly 80% from maximum to keep the cell temps down.

I have been away for 5 days, and will try to do more testing this weekend.

Not true.
Let me easy some of your worries. We can predict up to a certain point. The battery tube in the T1 has two open ends. The bottom end has the cap screwed on so we still have the top, which is open. It only has a pcb screwed on top. It is by far and without doubt the weakest area. A little bit of pressure and the circuit board and plastic shell will go flying. There is zero chance it could build enough pressure to act anything like a pipe bomb. The construction of the T1 is very different from your typical flashlight.

Here is a pic of the battery tube.

So flying plastic, maybe.
Explosion with metal shrapnel, no.

If you really wanted to, you could add a safety vent to prevent the plastic housing from popping. Take a 1/4 rubber plug and drill a hole a bit smaller. Push the plug in flush and you have a water tight, emergency vent hole.

I don’t think I’m that worried about it. I’ll make sure not you use any cells I think are not 100%. I’ll probably stick to the factory cells. I can also make sure to run it a bit below max brightness.

it is likely the cell i used that gassed that odour was weak & an older cell in my case.

I think that is the general consensus. No can really get their battery temps up real high.

Pressure/Temperature/Current switch:

I agree :wink:

What accusations was I making? I was considering owning one and was simply learning more about it, hence the question.

KuoH

I see what happened. You responded to a quote I made to Aleister, so I thought I was talking to him. Sorry about getting you mixed up with him. I’ll delete my earlier post. Sorry.

I hope you don’t consider my thoughts as accusations, they are my thoughts.

I own three T1s and loved them on my 12 days camping trip, as a matter of fact here is my opinion for T1: Anyone got a zanflare T1 lantern? - #192 by Aleister