Flash Review ThruNite TH20 Headlamp

Hi Ethan, I would be interested to hear if you find the run time information you seek.  Who ever provides it must have a way to measure lumens, as I am sure you know there is no 60 or 120 lumen setting on the light.

That said, I do like to characterize my lights when I get them by measuring the current demand from the battery on the different levels.  I don’t have a way to measure 60 or 120 directly, but I could likely approximate it based on other lights I have and let you know how much current the light draws between 1.5 and 1V.  This could be useful if you plan on using rechargeable or lithium primary batteries.  If you plan to run alkaline, I could sacrifice one and run it til it goes out if that interests you.

Likely will be a week or so, as mine is not scheduled to be delivered until toward the end of the week.

Thank you Matt that would be great. I only use rechargeable Eneloops or Energizer Lithium so no need to run an alkaline. It’s not necessary to get an exacting measure, but a rough measure based on other lights would be helpful. It would be a good way to compare it with the Zebralight H52w and H53w.

I emailed the manufacturer and will post if they send any info back. Will also ask on one of the flashaholic sites.

There is a good review of the light on Candlepower Forums.

http://www.candlepowerforums.com/vb/showthread.php?421166-Review-Thrunite-TH20-Neutral-White-(1xAA-14500)&highlight=th20

There is a good review of the light on Candlepower Forums.

Yeah, that is where I found the info on the low mode run time.  I said 2 days, but looks more like nearly a week.

FYI, the runtime in the infinity low 1.6 lumen mode is way more than 21 hours. I’ve been testing a cool white <span class=”highlight”>TH20</span> with a 2400 NiMH battery and it’s been running for almost 130 hours and voltage has only dropped from 1.41 to 1.24 V.

My Zebralight H52W weighs 70 grams with the stock headband and a lithium AA – 20 grams less than the Thrunite TH20, which is also made in China. The dreaded Zebralight double-clicks – set them once and forget about them. High, medium, low is good enough.

The Thrunite is cheaper, heavier, and functionally equivalent to the H52W for me. I’ll pass.

— Rex

“Your light going out with no warning was a function on the 14500 battery, not the headlamp. Those batteries have protective circuits in them that cut power off at a certain level to prevent over discharge.
Just so. I find the rechargeables to have less capacity than the standard Lithiums, they weigh more and they cost more. Not worth it. Don’t blame the headlight for the battery.”

Bottom line, was in the pitch dark and had to install a new battery in a dangerous spot. Happened more than once.

As for using non-rechargeable batteries, forget it.  The Energizers do have more capacity, but have to be disposed of after one use.  Will stick with the Petzl, and never again have to buy lithium Energizers and throw them out by the box load.  And will protect some eyes and help protect the environment.

never again have to buy lithium Energizers and throw them out by the box load.
Odd.
I have thrown out a few dead Energisers over the years – less than 6 I imagine. When they don’t have the capacity to drive a headlight, they often manage to drive something else, like a multimeter – for quite a while.

Cheers

Hi Roger,

Perhaps you do not have dogs who in addition to daytime hiking yearn for the trails and tracks on an almost daily basis.  During the colder months, it gets dark early, so many walks are in the dark, and go for well over an hour over hill and dale.  The lithium Energizers, AA or AAA, burn up quickly, so looking for rechargeable lithiums has been a priority.  They cost more, but the repeated use brings the cost down well below the Energizers.  So we may be looking for differing qualities in headlamps, not to mention their batteries.

Standard rechargeable AA batteries will give a longer runtime and will not abruptly die like the lithium rechargeable.  They will not be as bright but I will generally take runtime over brightness.

Hi Sam

Ah well, you are right. We try (very hard) to organise our daily activities to sync with the sun. So very different needs.

Mind you, I did try using rechargeables in the first Steripen model, and that was a failure. They could not support the 1 A draw the Steripen needed. Perhaps if they were treated more kindly they would last longer. Biased background.

Cheers

Standard rechargeable AA batteries will give a longer runtime and will not abruptly die like the lithium rechargeable.  They will not be as bright but I will generally take runtime over brightness.

Not necessarily true, especially with this light.  If I understand correctly, unless in turbo mode the light puts out the same lumens with the rechargeable lithium as with an alkaline or rechargeable NiMh.  Rechargeable lithium batteries store comparable energy to NiMh rechargables in this form factor.  So in turbo mode, the NiMh will last longer.  In the adjustable range of the light, 1.6 lumens to 230 lumens, they are comparable.   In one review I read the reviewer reported on run time as follows:

Runtimes on high (ramping mode) were as follows:
– 14500 (2015 Keeppower 840mAh protected) – rapid output decline and light cut off at 105 minutes
– NiMH AA (4th gen FDK Eneloop) – noticeable output decline from 70 minutes, 85 minutes until output reached ‘moonlight’ output. At 105 minutes output was at ‘firefly’ output and still going.
– Alkaline AA (Varta Longlife) – noticeable output decline from 55 minutes, 70 minutes until output reached ‘moonlight’ output. At 120 minutes output was still at ‘moonlight’ output and still going.

Non eneloop batteries will have more energy storage, as I mentioned above comparable to the rechargeable lithium.  While the lithium will last, it does suffer from the problem you mentioned of sudden cut off.

NiMH rechargeable pen cells I’ve used have continued to discharge while the appliance was shut off.  That is why many appliances using NiMH batteries work best if hung in a plugged in adaptor when not in use, so there is continuous charging while the appliance is shut off.  Great for the home, but not for the backpack, albeit Colin Fletcher called it ‘a house on your back’.  If the ‘Eneloop’ batteries are an improvement with more capacity, please let us know sourcing info.  Thanks.

There are two types of NiMh batteries.  Your standard ones will slowly loose charge, so in a year they might be 70% of full charge.  I did not research this number, I am going from memory here.  The low self dischage NiMh batteries will typically have maybe 75% of the capacity of standard NiMh, but will still have 70% of their capacity after 5-10 years of storage.  Eneloop are the most popular, and IMO best low self discharge NiMh batteries.  Then there are also higher capacity low self discharge NiMh batteries.  Eneloop Pro are one variety of these, and Duracell also makes one.  For AA they have capacity of around 2500mAhr for the Pro types, or 1900mAhr for the standard type.

I have some standard NiMh batteries around that are labeled 2650.  These are cheaper than the low self dischage ones, but don’t hold charge as well.  If you are using a light regularly then the low self discharge does not really buy you much, as you will recharge it before it has a chance to discharge much.

As far as where to buy them the low self discharge type, just search either eneloop, eneloop pro, or duracell rechargable.

Just getting back to reading your post, eneloops don’t have more capacity than standard NiMh, but the duracells and eneloop pros come close.  If you already have Lithium rechargeables and are happy with them I see no reason to switch.  but the eneloop pros would likely run longer and not cut out suddenly when the charge runs out.

Hope that helps.

Hi Ethan, I got my TH20 and spent a bit of time trying to characterize it today.  I did this at work, and did not have my other light as a reference for 60 lumens.  I was able to compare another single AA Thrunite light I have, Archer 1A V3, which has a setting near 60 lumens.  I measured the current the archer draws, and set the TH20 to that current with the same battery, then compared light intensity.  Unfortunately, the two lights have very different reflectors, the TH20 has a much shallower reflector, so it has much more of a flood.  So it looks dimmer than the archer.  I can imagine that the lights are putting out nearly the same amount of light, and drawing about the same amount of current.  The archer claims 5 hours at the medium setting, so I would guess the TH20 is going to get a similar run time.

Most lights I have are AAA lights, and due to their construction and access to the electronics I can characterize them pretty well.  The AA lights have the electronics buried deep in the tube, and applying voltage with my power supply is a bit tricky.  So I can not characterize them as well, as any time the current gets above 0.1A it is hard to keep things connected well enough to not affect the measurement.

Hope this helps, Matt

Looking at the review linked by Robert G., it does not appear that any NiMH battery will do better than the Lithium-Ion rechargeable, although as you state, the sudden cut-off might be avoided.  I found a helpful article at:  https://metaefficient.com/rechargeable-batteries/best-rechargeable-batteries-battery-chargers.html

Thanks for your responses.

Nice article, thanks for the link.

So I have gotten to use my light a fair amount the past couple days, including using it as a head lamp to work on my washer and dryer.  I found it comfortable to wear, and I really like the ability to fine tune the amount of light it produces.

I know I already quote above that the 21 hour rating used by the manufacturer is an understatement by a long shot.  I started my own test with an already used alkaline battery powering the light at the 1.6 lumen level.  In almost 2 days the battery voltage dropped from 1.48V by 0.1V.   Based on the current I measured for this level previously, and using 3000mAhr as the capacity for an alkaline battery, I calculated the light would run 10 days at the 1.6 lumen level.  I am going to let the light continue to run on this battery to see how close to 10 days I get with this used battery set on low, or 1.6 lumens per the manufacturer.

1.6 lumens does not sound like much light, but in the dark you don’t really need much light to see things up close.  Or to navigate around a house or camp.  And if you need more light, just turn up the brightness a bit.  Nice light for sure.

EDIT:  6 days in running the light at infinity low level on this used battery, still running, battery at 1.26V.  Going on an overnight tomorrow, so I took the battery out, will start up again when I return.

For context, let’s compare the ThruNite to the Armytek Tiara A1 v2 XP-L.

Weighs 48g vs 76g

Geoff,

The Thrunite TH20 is 77g on my scale, while the Armytek Tiara A1 v2 XP-L weighs 89.7g according to a gentleman on CPF.

Just to close the book testing I did to explore the the 21 hour rating at 1.6 lumens, I got 9 days on an somewhat used alkaline cell running at the lower end of the adjustable range.  Not sure why Thurnite puts 21 hours here any battery can run several times this, even rechargeable NiCd.

I have little complaint about web sites which make claims less than what the product can deliver.

Cheers

As usual, this discussion has rambled from the item specs to the merits of rechargeables to lithium; confusion about the tech merits of an item vs price value, etc.

For obsessive people who spend several thousand dollars assembling a UL kit, I doubt that saving $20 on an item as important as a light is a prime consideration.

I agree that runtimes at 25, 50 and 100 lumens are my prime considerations to compare against weight. Price is a very distant concern. From what I can see, as a single-batt light, the various zebralights appear superior, and when clocking in at over 3 oz, a petzl or black diamond also kills it.

runtimes at 25, 50 and 100 lumens are my prime considerations to compare against weight.
I think there has been a change in the scenery here.
When we used incandescent bulbs, there were indeed differences in efficiency and lifetime – small, but different.

But today we use white LEDS, mostly from a single source. That means that a torch putting out (say) 50 lumens will have a battery life almost entirely dependent on the quality of the battery. Cheap batteries from the net will have a short life; more expensive but better quality batteries (ie ‘brand’ names) will have a longer life.

That being the case, the big differences between brands and models today are going to be torch weight and ease of use. The latter covers both the physical design of the torch and the ‘user interface’. There can be genuine and reasonable differences in expectations for each of these. But this does mean that the older western ‘brand’ names may be no better than the latest made-in-Asia models. (The latest ‘brand’ name models probably come out of the same Asian factory anyhow.)

You get something very similar for small upright canister stoves these days: they all have about the same power rating and efficiency. Their CO emissions will depend on the burner to pot gap, and little else.
Cheers

Matt, after the test was finished, was the output at the low setting stronger than the firefly mode?
As to the manufacturer specs, Thrunite tested using a 2450mah Eneloop, you tested using an alkaline. I believe alkalines do very well in low drain scenarios.
Thanks for testing!

zoro, I decided the test was finished when the battery would no longer produce light.  I agree that the battery I used was different than the manufacturer.  Alkaline batteries have a capacity of roughly 3000mah at low currents.  I measured the current being drawn and estimated that I might eek out 10 days of light, but only got 9.  As the battery gets used, the voltage gets lower.  This light, like many quality lights, tries to regulate the current to the LED.  So as the battery voltage drops, the battery current must increase.  Gets to be a vicious cycle as the battery nears end of life.

The light looked as bright near the end of the 9 days as it did at the beginning due to this design of the battery, but I did not see the light extinguish.  Certainly 8 1/2 days in the light was just as bright as day 1.

Not exactly sure what sort of batteries or the life Roger was referring to above, but for alkaline batteries the $ you spend does not ensure quality by any means.  Dollar store alkalines last just as well as any “premium” ones.  But in general alkaline batteries are only viable for usage over 10 hours or more.  the only reason I use them is I can get them for free from battery recycle bins at my work.

For lithium rechargeables and nimh, I would generally concur with that statement, assuming life means many recharge cycles.

I realize that we all have our preferences and I too would much rather have a single larger battery vs 3aaa batteries. I found myself going a different route after recently fighting to get my aging BD Spot open to change the batteries in the dark. I picked up the Nitecore NU30 on sale for $34 and am loving it so far.

They say it’s 2.99oz with the built in 1800 mAH Li ion battery ( I don’t have a scale that accurate so I can’t give first hand knowledge) There is a single button for the red LEDs and another for the white. It starts on low and cycles up to max. It has some high CRI LEDs for task lighting like map reading.

The Petzl’s are nice but the core batteries cost almost as much as my whole headlamp. I know that the Nitecore will only recharge so many times, but it wasn’t that expensive either. Maybe after 300 or 400 recharges I’ll need to replace it, until then I think I’ll get my money’s worth.  Hopefully I can give a more comprehensive review after next weekend when I’ll have a chance to take it out in the woods. But until then, i think it’s a huge upgrade over my old BD lamp. and no more battery swaps ever! I just plug it into the battery pack I bring for my phone (topo maps/GPS). It will even run off of the external battery pack if I deplete the batteries and don’t want to wait for it to charge back up.