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

Glamping, eh? :smiley:

Well, that’s the only tent I know that’s perfectly Shipshape and Bristol Fashion

I agree on the UI, it can use some better programming. as it only has ramping its near impossible to test run times other than on maximum mode. red is only one brightness along with the usual un-needed SOS, (especially in a lantern)

I was told about that sale earlier. Its still a really good sale price for this little lantern considering it comes with the battery.

Out of stock again.
AU$23.66 plus $5.48 shipping. Add another 10% for GST since July 1 we pay 10% GST on ALL imports (previously was only over $1,000)
Bargains are getting harder to find.

EDIT: – IMPORTANT TO ANYONE WHO OWNS THIS ZANFLARE T1 LANTERN - critical possible fire or damage hazard discovered from testing if you use a cheap, older, damaged, laptop—pull, or unknown wrapped cell.

the tube the battery is in, gets HOT when running on high, because this tube is the heat sink for the LEDs. (This could possibility be very dangerous, as to over heat a older or damaged cell to the point of thermal run-away and a catastrophic fire/explosion hazard if a bad or damaged 18650 cell is used. (they should have designed the lantern with a separate heat sink “sleeve” with an air space around the battery tube to allow the tube to stay cooler, or lower the maximum amps, or add a thermal-sensor to step the lantern down when it reaches 45 ~ 50 degrees C in the battery tube/heatsink.

- was testing runtimes with an older, weaker cell, and discovered the cell began to emit that “sweet smell of death” as it was getting so hot in the T1 lantern on maximum mode after 1 hour running with that battery tube being the LEDs’ heatsink. (-i just quickly grabbed a glove put the hot, gassing cell outdoors in case it began to fully vent .

This photo shows how the LED strip-board is directly contacting the center aluminum post that contains the battery. >>


What kind of heatsink design is this?

Oh. Probably cost cutting to get the price down for the lantern.

How hot does the tube get? As long as it does not exceed 50°C, there is no safety problem, only the cell’s cycle life will be affected.

my previous test was with the factor included cell, so i was running it tonight with a 3000mah cell to test run times, and it got really hot. ( i could not put my finger in the tube it was so hot) when i took the bottom cap off the tube & cap was really, really hot, and from a photo i seen they use that tube as the heat sink for the LEDs! - a very, very dangerous design…

i ran it for another 20 minutes with the original 2600mah cell, then measured the inside surface of the battery tube at 67 degrees Celsius. (on maximum mode in W/W which i measured at 0.89 amps on the tail cap. (the cool white mode on max pulls 1.02 amps.)

Oh crap.

I would ask for a refund ASAP. That is a very dangerous design.

This would have not happened if they had put a least a small aluminium plate.

Now I know why it was too cheap. That’s because it is too cheap.

No one should be jumping on the bandwagon until they get all the facts first.

We need to hear from the manufacturer about their thermal limit tests. It’s possible DBSAR has a malfunctioning unit. Probably not, but we need to gather up all the facts and data before condemning a product.

It is actually not that bad of a design seeing as most flashlights are made similarly. If you leave a flashlight running long enough the heat near the LED will travel down through the length of the battery tube and it will heat up the battery just the same. I guess the big difference between a flashlight and this lantern is that one has an exposed battery tube so that the surrounding air can pull heat away from it. The lantern doesn’t have any way to circulate the air around it’s battery tube.

It’s quite possible that this entire situation can be fixed/corrected by using a simple insulating sleeve around the inner battery tube to prevent a battery from touching the metal walls and absorbing that heat.

A long-term solution would be for the driver design to be tweaked to step down the brightness at a certain temperature.

That link is taking me back to post #11.

Not to be deliberately contrary but I’m doing a test at the moment with the OEM cell.
So far I’ve run the light for 65 mins on MAX WW. The battery is no more than mildly warm and the inside of the battery tube is the same.

The lantern is hanging by the metal handle and nothing is touching the tailcap to act as a heatsink.

However, ambient temp here (winter) is only 14C (57F) today. What might happen over our 40C (104F) summers is anyone’s guess.

Obviously more testing to be done. I just kicked it to MAX CW about 10 mins ago.
A spot check reveals the resting voltage (straight out of lantern) is only 3.60V so it may be a bit pointless to continue without a recharge, but I’ll let it go for now.
I will try again with a freshly charged Panny 3400 or similar when the current cell cuts out.

With the greatest respect Den is it possible you have a higher ambient there or perhaps as JasonWW suggested, there may be some variation between batches or perhaps even a faulty unit?

With so many of these having been sold through the group buys, I hope a few other users can run some tests and report back too.

EDIT: Sorry, but I can only give subjective temps at present as my IR thermometer is elsewhere.

I have never had any flashlight (factory or modified) heat a battery as hot as this in my T1 did last night. The LEDs are in direct contact with the battery tube wall, (no flashlight does this.) this is the first time i have any light heat the cell up so hot to the point it began to gas. (the sweet smell before it begins its thermal runaway and vent.) I’m not condemning this light, i’m expressing a potential dangerous design flaw if consumers use a damaged or old cell in such a design where the battery tube is “directly” heated by the LEDs at high modes,
which i will stand by my decision is a very bad, flawed design to do that in the first place. (same scenario as lighting a propane camp stove that rests on its propane tank that feeds it)
Its ok for most if us who are experienced with LithiumIon cells and its characteristics and limitations, but this is a potential safety issue to the un-trained public. from past experience I testing cells to the point of venting flames, i know the warning smell all to well before a LiIon goes nuclear. Lithium Ion becomes unstable at high temps, and the potential with this design exposes that risk. I heated a running flashlight with a 18650 cell in it to the point of it exploding. (see my video from a few years back) the design of this light as a flaw that needs to be addressed, as its using the LEDs to heat the battery tube directly. Zanflare can easily fix this issue in a few ways, one is like you said is to tweat it down to a maximum of 0.65 amps draw, ( i did just that after with my T1 using a amp meter and ramped it down to 0.66 amps ( about 80% from max on the W/W mode) and the battery tube stabilized at a 55 to 57 degree temperature after 40 minutes. ( still to hot for my thoughts, but less than running on maximum.) another fix is to have a “shell tube” outside the battery tube for the LEDs to contact, leaving an air-gap from the LEDs and the battery center tube, preventing the conduction of heat to the battery.
in reality no flashlights i ever seen has hot running LEDs all around the sides of the battery tube/body in direct contact with it. Also, nobody is going to walk around, holding a modded flashlight that manages to conduct enough heat to the battery body for a hour or more continuously. Lets get realistic here… Metal at 65+ decrees C is very uncomfortable and nearly impossible to hold in a bare hand for more than a few seconds, let alone a hour. In this case of a lantern, it can sit there on a table or hanging in a warm tent, for a couple hours getting hot, cooking the cell at temperatures beyond what we can endure for a few seconds on a bare hand. There are reasons why Tesla liquid cools their massive 18650 cell banks… this cell chemistry is not stable, nor safe at extreme temperatures for long periods of time.

I will perform another test tomorrow or next week using the factory cell and my temp-meter at the maximum modes, (but will do this in the garage this time.) when i did the test last night with the cell over heating, the temperature inside the tube was to hot to put a finger in. I did a test after only running it at roughly 80% with the factory cell, and got a 67 degree Celsius in the tube. (higher than i care to continue using it continuously at that temp or higher.

How did you measure the temperature inside the tube? Did you measure 67°C right after you took out the battery? If so, actual temperature in operation might be even above those 67°C as the tube immediately cools down when you turn off the light.

Another short-term fix would be to swap out the factory battery for a protected 18650.

One of the things the protection circuit protects against is overheating.

I’m not around my Lantern at the moment, but if you wanted to test out a protected cell in it, I would be really interested in the results. I don’t even know what the protection circuit would do in case of a over temp situation. I guess cut all power to the cell. I’ve never actually tested that.

i measured it maybe 30 seconds after i removed the cell, (second test with original cell) using a infrared-type temp meter i use for all my heat testing)

good point, i don’t know if all protected cells have a thermo-cutoff sensor in the tail cap protection circuits, as i known them more for protection from over charging & over-discharging. I do have protected cells, and can do a test using one of them to maybe.

Two big factors limiting your temp here.

1) Ambient temperature, light will reach temperature equilibrium when it is X degrees hotter that the environment it loses heat to, so if it were 30C your light would get 16C hotter that it did under the same circumstances at 14C (difference could be from say 40C to 56C)

2) You had it hanging, so there is free air flow and convection current around the end of the battery tube. This is avoiding the biggest problem with this light, the lack of air cooling of the battery tube when sitting upright on an insulating surface like a wooden bedside table (which is also flammable)