[Review] Klarus XT1A (2018) (1000 lm, Dual tail switch, XP-L HD, 1x14500/AA, on-cell charging)

bmengineer · 2018-11-12T01:46:31.000Z

That’s disappointing, let me know how it works out

HONDARIDER · 2018-11-12T03:45:02.000Z

Mine seems to not have any flickering issue. I do wish it had a 4 or 500 lumen mode instead of the junp from 80 to 1000. Even a 200 lumen mode would work better.

bmengineer · 2018-11-12T13:27:04.000Z

If you’d prefer a lower high, you can always run it on a NiMH cell - That’s what I’m more likely to do.

bkp · 2018-11-12T14:43:46.000Z

I’m still awaiting further direction from Klarus, I’m not sure if they’re going to replace it or have me send it back for repair.

Another thing I noticed, the XT1A (at least mine) doesn’t work with a lithium primary (L91).

junglejim13660 · 2018-11-12T17:57:26.000Z

I over tightened the head to the barrel and the flickering has stopped. Shouldn’t have to do this with a new light. I found the Nitecore NL1485- 850mAh 14500 will not work in the XT1A due to it’s additional length. If this continues to be an issue, be sure to make a video showcasing the flickering, Banggood wants video proof of your issue.

bkp · 2018-11-12T18:02:15.000Z

Flickering with the provided Klarus 14500 is intermittent on mine. seems worse when freshly charged. the flickering is persistent with a NiMH or Alkaline, and over-tightening didn’t seem to make any difference.

Bravi · 2018-11-27T06:05:31.000Z

I FIXED THE FLICKER!

I just received this light a few days ago and noticed the flickering only on HIGH output. It also wouldn't let me change the output levels while it was flickering.

Based on junglejim13660's comments, I looked at the electrical contacts. Initially, I thought the contacts were the body threads themselves like a Surefire—but then I noticed the gold-ish ring inside the head unit (top of picture), and the very thin inner ring on the tail body (bottom of picture). It made sense to me that it was trying to push higher amperage across what is essentially a one-man rope bridge causing the flickering.

I grabbed a very flat knife sharpening stone and very carefully 'lapped' the tail body contact ring (bottom of picture)—almost as you would lap an AR-10/15 upper receiver—so that it would have a more even and flush fit with the head unit contacts. I cleaned the contacts and reassembled the light. No more flicker!

To check my theory, I loosened the body a tiny bit; just enough so that the connections made contact. Behold, the light flickered again. I tightened it back up with normal torque and the flicker is gone once again. The one-man bridge has been upgraded to wood. I assume the lack of bare aluminum contact surface is a compromise for a thinner overall body. Though, this fix is something that can be easily done in the QA process.

junglejim13660 · 2018-11-27T20:22:36.000Z

Good fix Bravi. I’m going use your method to permanently stop the flickering. I was also thinking that one or both of the mating surfaces were machined out of round.

I hope everyone who has this issue finds your post!

MascaratumB · 2019-02-04T15:03:00.000Z

@ bmengineer or anyone that has this light: is the bezel removable (even it if is “hard” glued)?

bmengineer · 2019-02-04T18:29:06.000Z

I couldn’t get mine off while I still had it, but I didn’t try any tools or heat.

MascaratumB · 2019-02-04T22:01:19.000Z

bmengineer:

I couldn’t get mine off while I still had it, but I didn’t try any tools or heat.

Thanks for the answer! I believe it is probably glued the hard way! I’m just making eventual plans for when my XT1C arrives :smiling_imp:
Thanks again! :+1:

bmengineer · 2019-02-04T22:52:17.000Z

MascaratumB:

bmengineer:

I couldn’t get mine off while I still had it, but I didn’t try any tools or heat.

Thanks for the answer! I believe it is probably glued the hard way! I’m just making eventual plans for when my XT1C arrives :smiling_imp:
Thanks again! :+1:

Just for curiosity’s sake, let me know if you manage to get into it.

MascaratumB · 2019-02-26T17:08:36.000Z

bmengineer:

Just for curiosity’s sake, let me know if you manage to get into it.

Sure will do

d_t_a · 2019-02-08T05:44:29.000Z

I would also like to share what may or may not be the same issue as the above.

On highest mode, whether with 14500 or AA battery, my newly-received XT1A (that was a few weeks ago) also has flickering. Unlike the above, the flickering does not stop in 10 seconds or 20 seconds, like what others mentioned. Instead, the flashlight will flash (like strobe) for a while, and sometimes go back to flickering. It sometimes can change modes but sometimes it’s more difficult to change modes with the paddle-switch, when this happens.

I have show this issue (made a Youtube video) to the online store where I got it, and they asked me for the serial number on the body tube. After giving them those info, they said that the problem is the tailswitch (body tube+tailswitch assembly). They then shipped me the replacement body tube/tailswitch assembly, which I just received.

After using the new replacement tube/tailswitch — the flickering does not occur anymore whether on 14500 or AA battery. So, it is indeed a body tube/tailswitch problem that’s causing the flickering issue.

d_t_a · 2019-02-19T09:19:13.000Z

Does the Klarus XT1A really have battery reverse-polarity protection?

I made an accidental “user-error”, I inadvertently placed the 14500 battery backwards on the body tube. When I clicked the button to turn on, there was no light (maybe tried clicking 3 times), so I unscrewed the body tube and noticed I had the battery backwards — when I placed the battery in the correct position, the flashlight now only blinks). Probably the driver got damaged by incorrect battery placement.

So this seems to mean the XT1A doesn’t have battery reverse-polarity protection?

bmengineer · 2019-02-19T11:45:58.000Z

d_t_a:

Does the Klarus XT1A really have battery reverse-polarity protection?

I made an accidental “user-error”, I inadvertently placed the 14500 battery backwards on the body tube. When I clicked the button to turn on, there was no light (maybe tried clicking 3 times), so I unscrewed the body tube and noticed I had the battery backwards — when I placed the battery in the correct position, the flashlight now only blinks). Probably the driver got damaged by incorrect battery placement.

So this seems to mean the XT1A doesn’t have battery reverse-polarity protection?

I have no idea, that isn’t something I usually test for.

MascaratumB · 2019-02-26T17:08:43.000Z

MascaratumB:

bmengineer:

Just for curiosity’s sake, let me know if you manage to get into it.

Sure will do

I already have my XT1C! However, as I didn’t dislike that much the beam it produces, I didn’t try to take the bezel out! I guess I will not consider that
Still, it is glued!!

About the Reverse Polarity Protection, asked by d_t_a, I didn’t test it on mine. Actually, after seeing his statement, I got afraid of putting the battery reversed :zipper_mouth_face: So i guess I won’t try it! Still, that information is not available in the User Manual (as far as I could perceived)!

Kenai · 2019-04-09T14:55:58.000Z

d_t_a:

Does the Klarus XT1A really have battery reverse-polarity protection?

I made an accidental “user-error”, I inadvertently placed the 14500 battery backwards on the body tube. When I clicked the button to turn on, there was no light (maybe tried clicking 3 times), so I unscrewed the body tube and noticed I had the battery backwards — when I placed the battery in the correct position, the flashlight now only blinks). Probably the driver got damaged by incorrect battery placement.

So this seems to mean the XT1A doesn’t have battery reverse-polarity protection?

According to the Klarus website, the XT1A is supposed to have reverse-polarity protection. It is one of the highlighted points listed on the 10th splash screen under Multi-Safety Protections.

Nsystem · 2020-06-22T03:56:21.000Z

Hey guys i received my XTA1 last week also had this light flickering issue when powering with the primary switch, revived an email back asking if i had made sure that it was screwed together tightly. I gave it a decent twist and problem was solced.as i isolate by unscrewing a quarter turn ill just need make sure its tightly screwed together.

yosaku · 2025-03-06T16:03:59.143Z

The flashlight flickering issue has been resolved.

Cleaned the following contact points and applied electrical contact cleaner:
- The silver-colored contact point on topmost edge of the body-side threads
- The gold-colored O-ring on the head side
Tightened the head and body firmly.