Review: Thrunite Ti4, the almost-perfect penlight

This Thrunite Ti4 was provided by Thrunite for review. The Ti4 is available from US Amazon and several other regional Amazon sites as well as Use coupon code "20%" for 20% off sitewide through January 7 2019.

A full album with extra images is available at

Quick Review

The Thrunite Ti4 is a 2xAAA flashlight with a form factor similar to a pen with a design suited to urban and indoor use. Compared to what's typical for the market segment, the Ti5T has a lower low, a higher high, and a choice of cool or neutral tints. At $20, the Ti4T is very competitive. There's a titanium version offered for $30 with a more floody beam pattern. Unfortunately, no high-CRI version is offered, or it would be the perfect penlight.

Size comparison: 18650 battery, Thrunite TH30, Thrunite Ti5T (heat colored), AAA battery, Thrunite Ti4, BLF 348, Streamlight Microstream

  • + Nice tint and beam pattern
  • + Good sub-lumen low preserves dark adaptation well
  • + Low available directly from off
  • + Classy appearance
  • + Titanium option at a very competitive price
  • + High value
  • + Can tailstand in a pinch
  • - Low CRI
  • - Always starting in low may be confusing or inconvenient for some users
  • - Voltage-based output rampdown in medium is odd and unhelpful
  • - Low grip

Ideal use cases

  • Everyday carry with business dress
  • Secondary close-up light for mechanics, pilots, etc...
  • Secondary to a larger light for low illumination without impacting dark adaptation
  • Gift for anyone who doesn't have a decent small flashlight
  • LED swaps

Unsuitable use cases

  • Heavy outdoor use
  • Medical examination or other situations where color acuracy is a priority

Details and technical analysis


The Ti4T comes in aluminum or titanium, cool or neutral white. The aluminum version uses a Cree XP-G2 emitter for a more focused hotspot, and the titanium version uses a Cree XP-L, for a larger hotspot.

This is the aluminum, neutral white version.


The Ti4 comes with a user manual and spare o-rings.

Modes and user interface

The Ti4 has a reverse-clicky tailswitch. That means a full press and release of the switch is required to turn on the light, and subsequent half-presses will cause it to blink off until released. There is no difference, as far as the Ti4's driver is concerned between turning light off and back on quickly with two full presses, and using a half-press.

State Action Result
Off (more than 10s) Full-press Low
Off (1-10s) Full-press Last used
On Half-press / power cycle (less than ~1s) Cycle modes L->H
On Full-press Off
On 7 half-presses Strobe

Extremely short half-presses don't register as such and leave the Ti4 in the same mode.

Output and runtime

Advertised performance is with unspecified 850 mAh NiMH rechargeable AAA batteries. Tests were conducted with Panasonic Eneloop 750 mAh NiMH rechargeable AAA batteries.

Mode | Advertised Lumens | Estimated Lumens | Throw (FL1 meters) | Graph | Advertised Runtime| Time to 80% | Time to 50% | Time to 10% ---|---|---|---|---|---|---|---|---|--- Low | 0.3 | - | - | - | 137 hours | - | - | - Medium | 24 | 40 | 24 | graph | 12 hours | 4 minutes | 31 minutes | 10.8 hours High | 252 | 252 | 61 | graph | 51 minutes | 29 minutes | 40 minutes | 43 minutes

The rampdown observed in medium appears to be based on voltage. Resetting it does not result in the original output level. High output tested exactly as advertised, to the lumen.

Additional graphs

I did conduct an additional test with Ikea Ladda 900 mAh batteries and got 52 minutes to 10% on high.

Light quality

The neutral white XP-G2 in the Ti4 produces a coppery tint that looks a bit under 4000K without significant green or red off-colors. It's pleasant on a white wall, with less tint shift than many of the emitters that have been finding their way into new designs. CRI is unspecified and likely in the low 70s. The relatively warm tint does help outdoor scenes look more natural, but colors are noticeably less vivid than with higher CRI lighting.

White wall



The Ti4 is lightweight, with a comfortable, secure pocket clip and proud switch. The body is smooth with no texturing, which is fine with bare, dry hands. It's not so good with wet or gloved hands. The pocket clip is effective, easy to insert in a pocket, and leaves what I think is just the right amount of tailcap exposed.

The Ti4 can tailstand on a very flat, level, hard, unmoving surface.


The Ti4 has a smooth anodized finish with no visible flaws. The conventional threads are smooth and turn easily. My only quality concern is that the finish on the pocket clip appears to be black paint, which likely won't wear as well as the rest of the flashlight.


The Ti4 is designed for use with two NiMH rechargeable AAA batteries. Disposable lithium AAA batteries are also usable, as are alkaline AAAs with reduced performance.

Modification potential

The Ti4 uses a threaded pill to hold the driver and MCPCB. It's easy to screw out and access components with the only difficulty being the tight spacing compared to 18650 powered lights.. All the 3-volt 3535 emitters should work. The head is identical to the Ti5 with the difference in output being entirely due to input voltage, so I was able to try the emitters I used in my Ti5T with the Ti4 as well.

I've used all of the following in the Ti5/Ti4: Cree XP-G2 and XP-L, Nichia 219C and 219B, and Samsung LH351C. I found the XP-L a bit short on throw, though everything is going to be floody in this small a reflector. The 219B is my favorite for the application, but hard to come by lately. The 219C and LH351C are very similar with the Samsung being a little cheaper, a little brighter and a little less green. Relative to the XP-G2, output increases a bit to 290 lumens, and throw drops a bit to 54 meters.

I selected the LH351C for a permanent home in the Ti4, while my Ti5 gets a 219B sw45k R9080 - an extra-rosy, extra-high-CRI version.

Recommendations to the manufacturer

  • Consider LED manufacturers other than Cree.
  • Offer a high-CRI option.
  • Bring back the Ti5. It remains my favorite 1xAAA light.

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