Fenix E35R Flashlight

For a home power outage, the Fenix E35R can be the house’s main handheld light, on two conditions: somebody keeps it charged, and a power bank or a charged spare 21700 battery sits in the same drawer. It takes no AA or AAA batteries. Its 3,100 lumens are a short burst; Medium is the setting for the evening and Eco the one for the night. One owner, a month in, says the quality has been great, and 1Lumen and Knivesandtools both describe a strong magnet in the tail. The complaints are about a switch that wakes up in pockets and a charging port that two owners found fussy about adapters and cables.

Every fridge door holds a magnet from a pizza place nobody has called in years. It is holding up a menu. It could be holding up a flashlight.

The E35R has a strong magnet in its flat tail, and 1Lumen says it sticks easily to steel surfaces like a car hood or an appliance. If the pizza magnet sticks to your fridge, this will too. Put it high on the door, where every adult can find it when the lights go out after dinner. Fenix’s manual asks you to keep the light out of the reach of children, and Space.com’s reviewer could comfortably cup the head in Turbo for only about five seconds. This is the grown-ups’ light.

What arrives, and which E35R it is

Fenix packs the Fenix E35R with its own 21700 battery, the ARB-L21-5000 (5000 mAh), a USB-C charging cable, a lanyard, a spare O-ring and a body clip. 1Lumen found the same set in its box, with the clip already fitted. The light is 120 mm long and weighs 148 g with the battery, per Fenix; one owner compares its size to a permanent marker.

Check two things when the box arrives. First, the battery. Fenix lists it as included, but when our research looked on October 22, Amazon’s page behind our button did not name the battery among the included parts. Second, the name on the light. The E35 V3.0 and the E35 UE are other models. The V3.0 is the E35R’s predecessor, and 1Lumen notes that it charged through a port on its battery, where the E35R has a USB-C port on the light itself.

Fenix Lighting USA says its ARB-L21-6000 battery works only in an E35R bought in or after 2025, and on that same October check, Amazon’s page did not say which production run it ships. If you buy a spare, the ARB-L21-5000 is the one Fenix lists for this light.

The 3,100 is a sprint

Turbo is the number on the box, 3,100 lumens and a 260-meter beam by Fenix’s figures, and it is short. 1Lumen measured 3,477 lumens at switch-on, 2,772 lumens thirty seconds later and 1,141 after ten minutes, with the outside of the light at 58°C by the thirty-second mark. A BudgetLightForum reviewer put full brightness at about half a minute. Fenix’s manual gives the reason: on High or Turbo, the light steps itself down once it reaches 60°C.

Medium is the setting that holds. In 1Lumen’s measurements it started at 397 lumens and was still at 395 after ten minutes. Its ANSI runtime came to 8 hours 43 minutes, against Fenix’s 9 hours 20 minutes. ANSI runtime ends when the output drops to 10% of its level thirty seconds after switch-on, not when the light goes dark, and 1Lumen’s unit kept running on Medium for 10 hours 39 minutes before it shut off. The BudgetLightForum reviewer called Medium an excellent running light, with enough of it for the whole night. That covers dinner, the dishes and the homework somebody remembered at 8 p.m.

At night, drop to Eco. It is 30 lumens, and Fenix lists it at 69 hours, just under three days of continuous light; 1Lumen measured 31 lumens but published no Eco runtime. Thirty lumens is not dim. Space.com calls it still pretty bright for reading and would have liked a setting around five. The Knivesandtools reviewer wanted a 1-lumen moonlight mode and suggests an optional diffuser to spread the beam.

The flat tail helps at night. 1Lumen says the light stands on its tail easily, and the Knivesandtools reviewer says it can be used as a candle. A commenter who had sat through several multi-day blackouts, writing about outage lights in general in 2018, found 10 to 50 lumens the most useful, bounced off the ceiling. Eco’s 30 lumens sit inside that range. Stand the E35R on the kitchen table, set it to Eco, and the ceiling becomes the lamp.

Fenix’s full mode-by-mode table is in our emergency flashlight guide.

Charging when the wall socket is dead

The E35R charges through a USB-C port on the side of its head, under a rubber plug. Fenix puts a full charge at about three hours from empty and recommends a 5V/2A or stronger adapter; 1Lumen’s charge took 3 hours 1 minute. The indicator in the switch shows red while it charges and green when it is full. Close the rubber plug afterward: Fenix ties the dust and water protection to it.

During an outage, a power bank can supply that charge. Fenix’s manual says the light works while it charges, except in Turbo, High and Strobe, so it can sit plugged in and still give Medium, Low or Eco. Our power bank guide covers the bank.

Test the pairing tonight, while the lights work. One owner found that only a few of their USB adapters would charge it. With one adapter it made a high-pitched sound and the charging light stayed off, and a replacement unit did the same. Another owner found that the slightest bump knocked the cable out and stopped the charge, with three different cables. Two owners are not every unit. They are a reason to plug in the very bank and cable you will rely on, before you have to rely on them.

The other route is a spare battery, already charged. One full ARB-L21-5000 V2.0, the battery Fenix packs, is good for 9 hours 20 minutes on Medium or 69 hours on Eco by Fenix’s figures, and a charged spare of the same battery adds the same again on paper. How many outage days that makes depends on how long Medium stays on each evening. 1Lumen concluded it needs a button-top 21700: two flat-top cells it tried were too short to make contact. Fenix recommends its own ARB-L21 series and a protected battery, and the battery indicator and low-battery warning work only with the ARB-L21 series.

Working it in the dark

Everything happens on one side switch. Hold it for half a second to turn the light on or off. Click to step up through Eco, Low, Medium, High and Turbo. Hold it for 1.2 seconds for strobe. Double-click while it is off to lock it, and double-click again to unlock, which switches it on in Eco.

It remembers the last mode, except Turbo, High and Strobe; switched off from Turbo or High, it comes back in Medium. So switch it off in Eco at bedtime, and Eco is what the 2 a.m. trip down the hall gets.

Finding the switch is the harder part, two reviewers say. The Knivesandtools reviewer says it is “a little more difficult to find, especially in the dark”. Space.com turned the clip so it sits directly behind the button, which made the button easier to find quickly in the dark.

With the light off and unlocked, one click shows the battery level for three seconds: green, flashing green, red, flashing red. Space.com’s note on the last step is that flashing red can mean a quarter of the battery or almost nothing. When the battery runs low, Fenix says the light steps itself down until it reaches Eco, and then the indicator blinks red.

Two flashlight forum writers disliked the interface. One owner on r/flashlight called it a deal breaker and plans to give the light to a family member who will not be bothered by it. The BudgetLightForum reviewer called it primitive, then wrote that it is exactly the flashlight they would give their dad, who needs a light that is bright, reliable and easy to use.

The people who find it too simple are not the people it is for.

The pocket, the lock and the hot head

Fenix’s manual asks you to switch the light off and lock it, or take the battery out, before it goes into a pocket or a backpack. It also warns that the shell gets hot enough to scald. Owners show why both warnings are there. One reports that the light switched itself on several times even when locked, and now carries it with the body unscrewed a quarter turn. Another, in the same thread, says it burned them a couple of times while they carried it as an everyday light.

Space.com was glad of the lock for the same reason, worried that Turbo might switch on and burn a hole in a bag. The Knivesandtools reviewer says Turbo becomes almost impossible to hold after a couple of minutes, and prefers turning the head over the double-click as a lockout.

At home, the answer is the fridge door. A light hanging on a magnet has nothing pressing on its switch. For a coat pocket or a go bag, do what Fenix asks: lock it, or take the battery out.

Where it lives between outages

Fenix asks for a recharge every four months to keep the battery in good shape, and for the battery to come out if the light will sit unused for a long time. That makes the E35R a calendar light, not a drawer light: three reminders a year, and each one ends with a charge.

The magnet’s one cost, says the Knivesandtools reviewer, is that keys and anything else kept close end up stuck to it. On the fridge, that is mostly the pizza magnet’s problem.

Straight from the threads

Who should pick something else

If you want a light that runs on AA or AAA batteries from the store, this is not it. The same blackout commenter preferred lithium primary batteries for emergency lights, for their 10-plus-year shelf life, because rechargeable ones lose power over time. Our emergency flashlight guide does not cover an AA flashlight yet, and the example in our headlamp guide runs on AAA batteries.

If you want a very dim light for checking on sleeping kids, 30 lumens is as low as this one goes.

If the light will sit in a drawer for a year, untouched, the four-month recharge Fenix asks for makes this the wrong light.

Otherwise, charge it, switch it off in Eco, and put it back on the fridge next to the pizza menu. Only one of them will be useful in the next outage.