Review: NITECORE Explorer Series EA41 (4xAA)

subwoofer

Flashlight Enthusiast
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Author's Statement for Transparency and Disclosure
The test sample/s featured in this article were provided for technical testing and review by "NITECORE". Test samples are retained by the reviewer following publication of the completed review for the purposes of long term testing and product comparisons.
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NITECORE's EA4 proved to be incredibly popular with its compact design, high output and great throw. Thanks to its use of standard AAs, the popularity of this light spread beyond the normal fringes into a wider market that wanted high performance without getting into the world of li-ion.

Moving from the single two-stage button on the EA4, the latest incarnation of the 4xAA Explorer light, the EA41, now uses a two button switch and has an updated LED (XM-L2) with increased output.


05EA41angle.jpg



Author's note: many of the images used in this review are animated to reduce excessive scrolling. You may need to wait for the images to load fully.


Taking a more detailed look:

The photos here show; the packaging, contents, size in relation to an AA cell, tail-cap, LED, reflector tail-cap contacts and locator rods, battery tube with locator holes, tail threads, internal contacts, battery tube with four AAs loaded and the EA41 with the D4 charger getting ready to go!

EA41Overview.gif


Moving onto the EA41's holster to show the fittings on the back as well as the front view:

Holster.gif


To get an idea of size, the EA41 is shown here with (left to right) the NITECORE CU6, EA41, P20UV and P25.

14P20UVsizecomparison.jpg




The beam

The EA41's beam belies its compact form and use of AAs with a surprisingly strong beam.

The indoor beamshot shows what is quite a narrow spill beam combined with a punchy bright hotspot. This configuration gives the EA41 it's throw, but can give close range use a bit of tunnel vision.

A real benefit of this beam type indoors though, is that if you tail-stand the light, the spill be is narrow enough not to cause glare. Many wider beam lights can be uncomfortable to use on a table tail-standing due to their glare, but the EA41 works very well like this and is super stable.

Going outdoors, first up is a control shot featuring my regular point of comparison the Fenix TK41. The TK41 uses 8xAA and has a similar beam with great throw.

Compared to the larger TK41, the much smaller EA41 stands up very well and its slightly broader hotspot makes it a more useful light while retaining good reach.

EA41Beamshots.gif




Modes and User Interface:

One of the key differences between the EA41 and its predecessor the EA4 is the change from a single two-stage switch to a two (single stage) button switch. As much as I liked the NITECORE two-stage switches, they can become a bit 'tricky' from time to time especially if using gloves.

Personally I find the new layout far more intuitive and much easier to use. There is direct access to maximum and minimum modes as well as simple activation of the locator switch illumination

06EA41anglebuttons.jpg


The two buttons are the Power and Mode buttons.

Pressing the Power button will switch the EA41 on and off, returning to the last used steady output mode. When on, pressing the mode switch cycles through the steady output modes.

When on, pressing and holding the Power button for more than 1s will put the EA41 into standby mode which flashes the switch illumination to act as a locator beacon. This is disabled the next time you switch the EA41 on and off, so if you wish to have the locator function showing you need to switch off by pressing and holding the power switch. (Note in this image the flash frequency appears slightly faster than it really is)

EA41switchflash.gif


From off, there is direct access to Turbo (using the Mode switch) or Lower (using the Power switch) by pressing and holding the appropriate switch for more than 1s.

Special flashing modes are accessed by pressing and holding the Mode switch when the EA41 is on.

The EA41 has a lockout mode as well. When on, lockout is accessed by pressing and holding both switches for more than 1s. After switching off, the EA41 gives one bright flash to indicate it is entering lockout. To exit lockout press and hold both switches for over 1s.

These are just the main features, for more detail see the full user manual here:
NITECORE EA41 User Manual



Batteries and output:

The EA41 runs on 4xAA cells. Despite looking like it might be able to run on only 2xAA, it will not, so you do need a set of four matched cells to fire up the EA41.

On inserting a fresh set of cells and screwing on the tail-cap, the EA41 switch will flash to indicate the power level. Three flashes indicated full power, with this reducing to two or one if power is low. This indication can be brought up at any time by pressing the mode switch with the EA41 off.

(Critical note – see below regarding Parasitic drain and inserting fresh cells)

Keeping this test as 'NITECORE' as possible, the EA41 was powered using AA cells charged with the NITECORE D4 charger.

To measure actual output, I built an integrating sphere. See here for more detail. The sensor registers visible light only (so Infra-Red and Ultra-Violet will not be measured).

Please note, all quoted lumen figures are from a DIY integrating sphere, and according to ANSI standards. Although every effort is made to give as accurate a result as possible, they should be taken as an estimate only. The results can be used to compare outputs in this review and others I have published.

NITECORE EA41 using Panasonic ACCU NiMh AA cellsI.S. measured ANSI output LumensPWM frequency or Strobe frequency (Hz)
Turbo8160
High4900
Medium1490
Low550
Lower20

Measured beam range comes in at 324m. Beacon mode flashes once every 2.1s. Strobe frequency is 19.2Hz

As there is an electronic switch we need to consider the parasitic drain. When measuring the parasitic drain of the EA41 a particular feature (so far unique to the EA41) was discovered and is very important for users to know about.

When inserting the cells, and closing the tail-cap, the EA41 has an initial power on state which has a much higher drain current at 568uA. At this drain current, fully charged NiMh cells will be completely drained in 139 days. This is very bad, however it is not the full story…..please read on.

Measuring parasitic drain is usually a simple matter of completing the circuit with an ammeter. Like this it is often difficult to operate the light, and the current used in normal operation would generally damage the ammeter. In the case of the EA41 it was necessary to use some special high current jumpers to allow the switches to be operated and then to turn the EA41 off while maintaining the circuit. One of the jumpers could then be substituted for the ammeter after switching the EA41 off again.

Having turned the EA41 on and off again, the parasitic drain current drops significantly to 106.7uA. At this drain, the same cells would take over 2 years to be depleted. Much better! This is the same current present in lockout mode, so you don't get a lower drain in lockout mode, just protection against accidental activation.

IMPORTANT NOTE: Remember to switch the EA41 on and off after inserting fresh cells or the parasitic drain will be much higher.

The EA41 has a particular output profile with the Turbo output. After switching onTurbo, the output is held at nearly 800lm for 3 minutes after which it then gradually declines for the next 4 minutes to around 620lm, then maintains this for a further 13 minutes before dropping to 430lm (just a little less than the high mode of 490lm). If not reset, this 430lm output is then maintained as long as the cells will allow.

For the runtime test I have completed two runs. One with the Turbo mode activated and then no intervention and the second run where the Turbo mode was reset once the output had finished the gradual decline to 620lm. Both are shown on the same graph. Cell voltages at the end of each run were 1.0V-0.8V

EA41Runtimes.jpg




Summing up

NITECORE's update of the EA4 to the EA41 is a worthwhile improvement. Though I have always liked the two-stage button used on several models, I have also found it less than ideal in many situations. Moving to two single-stage buttons on the EA41 is not a step backwards, but improves the intuitiveness of the controls. Having the switches mounted on the side makes operation of the EA41 very natural.

NITECORE's uni-body concept keeps the EA41 incredibly compact. When loaded with 4xAAs, it becomes surprisingly heavy (mainly as it is so small) and yet reassuringly solid feeling. Quality NiMh cells are relatively heavy, and the EA41's weight nearly doubles when loaded with AAs (EA41 on its own is 154g, and with LSD NiMh cells is 264g). The flats on the sides of the body make for a very comfortable and secure grip with most of the weight in the hand.

Instant access to either the LOWER or TURBO modes makes using the EA41 a pleasure. There is also instant access to Strobe via a double click of the mode button when the EA41 is off. This comprehensively answers most users' needs.

Now that the default for the locator beacon flashes is off, it makes the EA41 much more bedside table friendly. If you need the locator flashes they are simple to activate, so can be used only when needed. Considering the drain current is higher when using the locator, it is much better that you have to choose to use it. These locator flashes are visible in a normally lit room, but are quite bright if used in a dark bedroom. If you are sensitive to any light (flashing or steady) in a bedroom, or have a partner/spouse who is, then you will not want to use the locator function at home, but if travelling and in an unfamiliar place, you might want to.

For a 'round-the-home' light, the EA41 works really well in several ways. The LOWER mode is good for getting round in complete darkness (though a moon mode is better if you wake in middle of the night) without creating a disturbance. The beam is bright enough to light a room well using a ceiling bounce, and most noticeable in the EA41 due to its ultra-stable tail-standing abilities, the narrow beam reduces tail-standing glare enormously. (With many lights, when tail-standing, a bright spill beam can often result in uncomfortable glare). So the EA41 is nice and compact, but packs the punch of a 4xAA light, sits very happily tail-standing, and has very useful output levels.

Great round the home, taking it outside, and the EA41 continues to get it right. The side switch makes it easy to turn on and off as needed, and the beam works well enough for path lighting, and very well for looking further afield. For those that want it, the strobe can be activated directly with a double click, and the focussed beam makes it very dazzling.

Make sure you remember to switch the EA41 on and off after inserting new cells (see previous 'batteries and output' section about the parasitic drain) to ensure the lowest parasitic drain. This is something that you should do naturally to make sure that the cells have been inserted correctly, are fully charged, and the EA41 is working correctly, so is not a problem, just something to be aware of.

With the power and runtime of 4xAAs, a versatile beam and ergonomic compact design, the EA41 crosses over between smaller single cell EDC lights, and larger, heavier, high-output lights. In this compact form you have a really great general purpose light.



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reserved for updates...

A minor observation I wish to add is that the NITECORE lanyards are amongst the best I have come across. They use a padded fabric tube for the wrist strap with sliding adjuster. This strap is comfortable, easy to use (the padding makes the strap slightly rigid so it is easier to get your hand into than a non-rigid strap), and seems far less subject to getting caught on velcro.

NEW INFORMATION:
Taking the investigation into parasitic drain further, I now have two more measurements to report.

1. As the EA41 initially starts with a higher drain when the power check is first shown, I was concerned that if you use the power check function at another time it might increase the parasitic drain. I have now confirmed that it does not. If you have the drain in the 107uA state, after the power check it is still 107uA.

2. The locator flashes will definitely increase drain. I have now measured this. Once the locator flashes have been turned on, the drain has a constant underlying drain of 503uA with peaks during the flashes of 1418uA. Using a logging DMM, I have been able to get an average drain current figure of 656uA. At this drain, the cells will be fully depleted in 121 days. So beware of leaving the EA41 in locator mode for long periods.


29/12/2014 - Additional note regarding inserting cells

- I have found that sometimes (in particular when using those cells with large flat positive buttons) when inserting new cells, the 'contact-mask' or 'PCB protector' used inside the battery tube can end up preventing a cell from making contact with the terminal. This means that on occasion, after replacing the tailcap, the EA41 might not turn on. The best remedy I found for this was to loosen the tailcap, hold the EA41 vertically and give it a little shake and then screw the tailcap back on. Doing this seems to allow the cell to settle down onto the contact and complete the circuit.
 
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So 960 lumens is not achievable on Eneloops? Would another kind of batteries make a difference? I like the throw, but the output is not what is advertised.
 
Thanks for the review! The biggest improvement over previous model is the switch.

And the addition of a proper moonlight mode :thumbsup: I know a lot of people missed it on the EA4.

Considering the drain current is higher when using the locator,

Do you have any numbers for this? would like to know what the drain is.
 
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Do you have any numbers for this? would like to know what the drain is.

No number for this at present. It is difficult to measure exactly as there is a peak in the current for each flash. There is also the issue I mentioned about using jumpers and the ammeter being damaged when trying to 'operate' the light to get it into a particular mode. When you are measuring in uA, getting a burst of 1A or more is very bad for the ammeter. This type of measurement is much easier in a single cell light, in a 4 cell light it gets tricky.

I'll see what I can do...

If I do manage it I'll also try and measure the drain after activating the power meter. As it is the power meter mode that the EA41 starts in when inserting new cells, I am suspicious of reactivating the power indication later on, and that this might put the drain back to the higher figure.

EDIT: - The only way to get an average drain current in locator mode will be to use a logging multimeter to record a trace of the drain. I've just remembered that my logging multimeter has a damaged mA/uA setting, so I have to get a replacement before I could attempt this.
 
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Very nice review!


So 960 lumens is not achievable on Eneloops? Would another kind of batteries make a difference? I like the throw, but the output is not what is advertised.

Nitecore is always innovating and trying something new. I like that.
However, their ANSI FL-1 estimated max lumens is usually higher than what other reviewers estimate.
This light gives you 760 lumens for several minutes when you hit Turbo.
It's probably around 20,000 Lux so it has some throw too.

One of the best AA batteries is the Eneloop Pro 2550mAh cell.
It will last a little longer, but it will not increase output, not even 4 of them at once.
There is a circuit driver in the light that regulates voltage.

The other multi-AA lights you can look at are the Eagletac GX25A3 and the Sunwayman D40A.

I consider the Low and Medium level brightness modes when choosing a light.
This light has 1, 50, 150 lumens which is pretty good.
 
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What makes the Eneloopes better than Alkaline? Ty

Eneloops are good NiMHs (rechargeable).
Eneloop Pro 2500mAh are a little bit better than Eneloops.

You can go to your local grocery store and get some other NiMHs that would be almost as good.
Duracell Rechargeable 2400mAh
Rayovac Recharge Plus 2400mAh: cheap but still good
Energizer Recharge Power Plus : meh


As to the difference between NiHM and Alkaline, you will have to do some research in the Battery forum.
 
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What makes the Eneloopes better than Alkaline? Ty

Eneloops are also the most popular LSD (Low Self Discharge) NiMh rechargeable AA. If you leave a normal NiMh cell, after about 1-3 months it will be completely dead. Eneloops and similar LSD cells lose only a small percentage each year, so work well for standby (especially as the risk of leakage is almost non-existent).

All rechargeable AA are better able to deliver high currents needed by powerful lights.

Alkaline are OK for lower drain devices and those you use regularly so you can replace the cells once depleted. Alkaline cells tend to leak once discharged (and left for some time) or if made to work very hard (high current).

There is no doubt that NiMh is the better option for lights, and LSD types mean they are suitable for 'standby' lights.
 
Do you have any numbers for this? would like to know what the drain is.

This information has now been added to post 2:

"NEW INFORMATION:
Taking the investigation into parasitic drain further, I now have two more measurements to report.

1. As the EA41 initially starts with a higher drain when the power check is first shown, I was concerned that if you use the power check function at another time it might increase the parasitic drain. I have now confirmed that it does not. If you have the drain in the 107uA state, after the power check it is still 107uA.

2. The locator flashes will definitely increase drain. I have now measured this. Once the locator flashes have been turned on, the drain has a constant underlying drain of 503uA with peaks during the flashes of 1418uA. Using a logging DMM, I have been able to get an average drain current figure of 656uA. At this drain, the cells will be fully depleted in 121 days. So beware of leaving the EA41 in locator mode for long periods."
 
Appreciate the effort you went to to get those numbers. They correspond very well with what Nitecore has in the EA41 User Manual.

Standby Mode
With the light on, press and hold the on/off switch for more than one
second to turn off the light and activate location beacon function. The
blue power indicator will flash once every three seconds to indicate the
location of the EA41. In this mode, the EA41 can keep running on 4 × AA
batteries for 120 days.
NOTE: With the power indicator off in standby mode, the EA41 can work
for more than 12 months with 4 × AA batteries.


[Bold is my emphasis]

Did you make your estimate based on LSD NiMH or alkaline?
 
Appreciate the effort you went to to get those numbers. They correspond very well with what Nitecore has in the EA41 User Manual.

Standby Mode
With the light on, press and hold the on/off switch for more than one
second to turn off the light and activate location beacon function. The
blue power indicator will flash once every three seconds to indicate the
location of the EA41. In this mode, the EA41 can keep running on 4 × AA
batteries for 120 days.
NOTE: With the power indicator off in standby mode, the EA41 can work
for more than 12 months with 4 × AA batteries.


[Bold is my emphasis]

Did you make your estimate based on LSD NiMH or alkaline?

It is based on what I consider to be the most appropriate cell, a LSD NiMh and my test cells are all 1900mAh, so this is the capacity I use.

When I talk about parasitic drain I always use the time to fully depleted, but of course the reality is that if it would take 2 years to deplete the cells, after 1 year you are down to 50%, so even this is not great as half of your potential runtime has gone down the drain. By giving the time to fully deplete the cells though, anyone reading my review can make up their own mind as to what is a minimum remaining capacity for their requirements. This might mean topping up the cells ever three months, or simply leaving the cells out of the light. There is no right way of dealing with parasitic drain apart from being fully aware of it.

Another important factor is that I have come across many instances where parasitic drain increases as the cells become depleted, so a fully charged cell drain might be quite low, but as the cell voltage sags slightly the circuit starts to draw more power. I can't really include all of this detail as my testing would take far too long to complete.
 
I continue to be impressed with this light for all the reasons discussed in the main review. I find myself reaching for this light regularly, compact, powerful and good throw.
 
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