Review: Wuben T102, a large 1x26650 light with USB-C

This Wuben T102 was provided by /u/swiling from Banggood for review. Use coupon code RD10OFF for 10% off regular-price flashlights at Banggood. The T102 is not in stock at present, and may not be restocked due to the pending introduction of a revised version.

The full image gallery is here

Quick Review

The Wuben T102 is a 1x26650 light with an XHP70 emitter, large reflector for respectable throw, sensor-based thermal regulation, USB-C charging and a boost driver that could provide stable output as the battery drains. Claimed output is 3200 lumens, but I measured over 4000. The tint is warmer than the claimed 6500K too - closer to 5500 to my eyes. The specs are a bit like a Convoy L6 with a shorter body and half the batteries. If you're already reaching for your credit card, slow down and read on.

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It sounds pretty good at a glance, but it isn't. It can make 4000 lumens, but the firmware really doesn't want it to do that. Despite having a thermal sensor, the T102 has a timed stepdown to just over 50% at 100 seconds regardless of cooling. You probably won't make it to 100 seconds though because there's also a low-voltage stepdown at 4.0V. Since batteries have some voltage sag under load, that means it needs to be fresh off the charger to not hit the low-voltage stepdown in 100 seconds. The included 5000 mAh 26650 will not make it to 100 seconds twice.

The user interface is also very badly designed. E-switches offer the potential of shortcuts to various modes from off, and sometimes from on. The T102 has only one such shortcut, to the mode I'm sure everyone will use most: strobe. A double-click from on or off activates strobe, which is extra convenient because single-clicks cycle through modes. Try to change regular modes too fast and you'll get the strobe mode you really wanted all along. Yes, you were trying to ask for low, but Wuben's programmers know best, you really wanted strobe. On/off with mode memory is a long press, but why bother with that when you could press twice faster and have strobe? There are no timed, voltage or thermal stepdowns on strobe either. You get full output until the low-voltage protection trips.

If you want a USB-rechargeable strobe light for your off-grid nightclub, the T102 may be for you. It's very good at that. It's not very good at much else though, which is incredibly frustrating because it could be a very good flashlight with a different firmware.

Instead, the T102 is like that one coworker we've all had. He does the job well at the start of the shift when the boss is watching, but as soon as the boss turns away, he's anything but productive, letting down everyone else on the team.

    • USB-C charging port
    • All-inclusive, ready to use
    • Tint and beam pattern are pretty good for an XHP70 light
    • Very short timed stepdown
    • Needless use of a timed stepdown in combination with a thermal sensor
    • Absolutely ridiculous low-voltage stepdown on a near-full (4.0V) battery
    • E-switch light with no shortcuts to any useful modes from off
    • Mode change often triggers strobe by accident
    • Charging is very slow for a 26650 at only 1.0A despite having a 2A USB wall wart

Details and technical analysis

Accessories

The T102 includes a Wuben branded 26650 battery, USB-C cable, USB charger with US and EU plugs and some spare o-rings in a fancy foam-padded case. The case is a nice premium touch, but a holster would have been more useful.

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User interface

My source for advertised specs is the Wuben T102 manual, which differs slightly from Banggood's product page. The user interface is as follows:

State Action Result
Off Long-press On
On Long-press Off
Off or steady mode Double-click Strobe
Blinky mode Short-press Previous state (steady mode or off)
Blinky mode Double-click Next blinky mode (strobe or SOS)
Steady mode Short-press Next steady mode (H -> L)

It's easy to hit strobe by accident when trying to cycle through modes quickly. I'm usually of the opinion that single-clicks to move through modes in a light with a only a single e-switch isn't a good design, but it's especially bad in combination with double-click triggering an unwanted action. I know the tactical mall-ninja market likes quick access to strobe, but with no momentary and a long-press to turn it on, this is not a tactical light. Making the token feature aimed at that market the one that's the most useless and obnoxious to everyone else is an incredibly bad design decision.

There are not shortcuts to anything else, just a long-press to the last-used steady mode. I'll grant that designing good UIs is hard and there's no way to please everybody, but it would take active effort to do worse than this. Bad ideas for next April Fool's Day include "always start on SOS" and "must pass strobe to turn off". Wait, I think I've actually seen the last one before. Maybe the T102 doesn't have the absolute worst UI on the market.

It has one of them though, which is a shame since the hardware has everything it needs to be a fairly nice flashlight. There's no need to design a brand new UI for this light; Wuben could emulate the behavior of the open-source Narsil ramping firmware, fer example. The latest Thrunite Neutron almost does that and it sounds quite pleasant to use.

Output and runtime

I must apologize for the lack of throw numbers and lumens for the lower modes. It seems I failed to record them, and I don't have the T102 with me as I'm putting the finishing touches on the review.

Mode Advertised Lumens Estimated Lumens Graph Advertised Runtime Time to 80% Time to 50% Time to 10% Tailcap current
Standby 0 0 0 - -
Low 13 - - 240h - - 139h 40mA
Med 212 - - 14.5h - - 14.4h 387mA
High 788 - graph 3.3h 3.6h 3.6h 3.6h -
Turbo 3200 4000 graph 1.3h 1 minute 31 minutes 42 minutes -
Strobe 3200 4000 graph - 92 minutes 92 minutes 92 minutes -

Yes, that's right, I included a runtime graph for strobe. This light seems to want so strongly to be on strobe, given that's it's only shortcut from off that I made a graph. It reveals that the driver is, in fact capable of maintaining more or less full output until it hits the low-voltage protection at about 3.0V. The driver performance seems to be pretty good - if only the firmware would let it stretch its legs.

My tests show the T102 beating its advertised output at 30 seconds on max. That's not much good for extended use though because the fun is over at 100 seconds. The stepdowns are ramped to make them less obvious, but the reduction in throw is easy to notice as objects in the distance quickly fade from view.

To test the stepdown behavior, I tried continually resetting the light. This was the result:

http://imgur.com/y6jQhb9.png

The period of full output becomes shorter as the voltage drops, eventually becoming zero. I measured this to be at about 3.97V.

To prove that this is voltage, rather than temperature related, I overcharged the battery to 4.35V. A minor overcharge like this poses no acute danger, but does cause as much wear to the battery as several normal charge cycles. This got me almost five minutes of full output before it started to ramp down immediately, just as giving that lazy coworker amphetamines might temporarily improve his productivity.

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There is no sign of PWM on any mode.

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Ergonomics

The T102 feels good in the hand. The switch is easy to access from multiple grips, and easy to find, being situated on a raised flat. It's a reasonable size and shape for a belt holster, but none is included. There's no anti-roll. The tailcap has a threaded hole for a tripod mount and can tailstand on a flat surface.

Battery and charging

The included Wuben branded 26650 is an unprotected flat-top labeled as having IMR chemistry. Its capacity tested at 5573 mAh on my Opus BT-C100. The onboard USB-C charger and included power supply charge the battery in about 6 hours and appear to terminate properly. An indicator light under the switch glows red during charging and blue when charging is complete. The battery indicator is not available except when the light is charging. It would be useful to have during operation.

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Modification potential

I've decided to start including modifications in reviews. Some people just can't leave well enough alone, and I'm one of them.

The bezel unscrews easily with a firm grip or strap wrench, and there's nothing at all surprising about what's underneath. Replacing this XHP70 with most other larger 6V emitters would be about as easy as you'd expect. Unfortunately, the emitter isn't what really needs changing on the T102.

I couldn't get to the driver. The head doesn't want to unscrew from the body tube; I'm net sure if it's glued, or actually not screwed together. Removing the switch doesn't grant useful access either.

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