Fenix HM75R review

We have not tested this headlamp. We own none of the products on this site and have no laboratory. This review works from Fenix's own product page, read on September 21, 2026, and the arithmetic those figures allow.

The HM75R is the outlier of this whole site. It carries an 18650 and a 21700 at the same time — a computed 30.2 watt-hours, more than any other product we cover, and about two and a half times the next best. Everything interesting about it follows from that decision, including the reasons not to buy it.

What Fenix publishes

That is a strong sheet. Two cell capacities, a beam distance, an impact rating and a charge time put Fenix comfortably ahead of most of the category — but note the two gaps at the bottom, because they matter more than they look.

The 30.2 watt-hours, and what they are for

The published 234 hours on floodlight is a maximum on a low setting, as these figures always are. The useful way to read the energy is the middle: this is the only headlamp we cover where a genuinely bright working level for an entire night shift is arithmetically comfortable rather than optimistic.

It also works as a power bank, with Fenix listing PD3.0, QC3.0 and several other fast-charge protocols. On a site with no power that is a real second function, though Fenix does not publish an output wattage so we cannot tell you how fast it charges a phone.

The weight is the whole argument against

The 170 g figure is the lamp without the rear pack and cord, and it is worth knowing that even stripped it is heavier than a fully assembled HM65R-T at 140 g. The mass is not only the battery case.

The beam, computed

7.8 candela per lumen is a moderately wide beam — more concentrated than the Petzl Actik Core's 5.3, less than the Streamlight ProTac HL-X's 27. For a work lamp that is sensible: enough reach to see across a yard, enough spread to work by. Compare it with the brightest headlamps, where two 3,000-lumen lamps sit at 3.1 and 2.1 candela per lumen and reach less far than this one.

The power bank, and what it is worth

Fenix lists the HM75R as discharging over USB-C with support for PD3.0, PD2.0, QC3.0, QC2.0 and several other fast-charge protocols. On a site or a multi-day trip that turns a headlamp into the thing that keeps a phone alive, which is not a spec-sheet bullet — it is a second device you no longer have to carry.

If you want to know what that is worth for your own devices, the arithmetic is simple and you can do it yourself: find the watt-hour rating printed on the device you want to charge, and divide 30.2 by it. Subtract something for conversion losses, which are real in any USB power-delivery circuit and which Fenix does not quantify. That is a better answer than any figure we could give you, because it uses your device rather than an assumed one.

Fenix does not publish an output wattage either, so how fast it charges is unstated. Protocol support tells you the negotiation is there; it does not tell you the current behind it. What is published is the energy, and 30.2 watt-hours is more than any other product on this site holds.

How it compares on energy per gram

That ratio is the best defense of the design. The rear case looks like dead weight and is in fact the opposite: a larger cell pays a smaller proportional penalty for its casing, contacts and housing than a small one does. Every gram of the HM75R carries more energy than every gram of a Swift LT.

It does not follow that you should buy it. Total mass is what your neck feels, not mass efficiency, and 321 g is 321 g however well the grams are spent. But it does mean the weight is buying something real rather than being wasted on packaging. Brightest headlamps sets the full table out.

Two gaps worth stating

• No IP code. Fenix states the lamp is completely waterproof and rates it to 2 m impact, but gives no IEC 60529 rating. That is a meaningful claim we can repeat and cannot place on a scale — unlike the HM65R-T, which publishes IP68. For a lamp at this price it is a conspicuous omission.
• No per-mode runtime. Fenix gives 234 hours on floodlight and 365 on red, both maxima, and does not break the spotlight and floodlight levels out individually. So the middle of the range — where you will live — has to be reasoned from the watt-hours rather than read off the page.

Who should buy something else

Skip it for anything recreational. 321 g is a work decision. For hiking, running or camping the Actik Core at 88 g or the Petzl Swift LT at 43 g are in a different category of comfort.

Skip it if you want a coded waterproofing rating. The HM65R-T publishes IP68 and costs meaningfully less.

Skip it if you want maximum output. 1,600 lumens is mid-pack; the Nitecore HC75 UHE and Olight Perun 3 both publish 3,000 — though neither publishes a runtime, so what that output costs is unknown.

Skip it if a rear battery case is a non-starter. Some people cannot stand the weight distribution, and no specification will tell you whether you are one of them.

The verdict, stated as what it commits to

On published evidence this is the headlamp to buy when the job outlasts every other lamp's battery. 30.2 watt-hours, 223 m, a 2 m impact rating, a power-bank function and both weight figures printed is a strong, checkable sheet, and the energy figure is not close to being matched by anything else we cover.

What it is not is light, cheap, brightest, or rated on the IP scale. Buy it for the shift that does not end, and wear something else the rest of the time. For the wider field ranked on the energy behind the claims, see best headlamps.