NITECORE EA8 Caveman Review (8/4xAA)

subwoofer

Flashlight Enthusiast
Joined
May 5, 2010
Messages
2,501
Location
Hove, UK
NITECORE caused a stir with their AA powered EA4 Pioneer, and have now followed it up with the EA8 'Caveman' powered by 8 AAs.

The EA8 takes the principals of the EA4's design but doubling the power supply and improving range with a larger reflector.

With the array of li-ion powered lights on the market, in the EA8 NITECORE brings great performance to those who prefer to stick to good old AAs.

04-EA8angle-.jpg




Initial Impressions:

For a light housing 8 AAs, the EA8 is remarkably compact, much more so than any other light I've come across that runs on 8 AAs.

Thanks to this compact form (made possible by the design not using a separate battery carrier) and the convenient side switch, the EA8 handles really well.

I was very pleased to find the EA8 comes with a belt holster. A really strong point as I want to be able to carry my lights with me. The holster allows for flexible carry options as it has a D-loop to suspend it, and a choice of fixed or Velcro belt loops.

From the moment I opened the box, I was chomping at the bit to get it loaded up with AAs and put to use (and as a note to any readers, I always finish the photos of the light and contact surfaces etc before I can start to use it so you can see it in the 'just out of the box' condition, so I did have to wait).



What is in the box:

The EA8's retail packaging.

01-EA8Boxed-.jpg


Included are the EA8, belt holster, lanyard, instructions and spare o-ring.

02-EA8unBoxed-.jpg




Taking a closer look and looking inside:

The EA8's body has a ribbed grip with two flats that have the branding and model information laser etched into them

09-EA8straight-.jpg


Looking closely at the etching there is a slight chiselled look to it which is very much in keeping with the 'Caveman' name.

05-EA8detail-.jpg


Unlike most of the other two-stage (camera shutter style) switches on NITECORE lights, the EA8 has a black rubber boot covering the switch just as on the EA4.

06-EA8buttondetail-.jpg


The tail-cap has a cross shape machined into it which incorporates a lanyard hole, and all around the tail-cap is crisp knurling to provide grip when fitting or removing the cap.

07-EA8tailcapdetail-.jpg


Heat sink fins surround the base of the reflector and include longitudinal grooves like those on the P25's head.

10-EA8heatsinkdetail-.jpg


A flawless deep reflector gives the EA8's beam real punch.

12-EA8tall-.jpg


The EA8 uses a XM-L U2 LED

13-EA8LED1-.jpg


The square yellow shape of the well centred LED's surface is shown magnified in the reflector.

14-EA8LED2-.jpg


The tail-cap contacts are a special rotating circuit board with locating pins to ensure it lines up correctly with the four columns of AA cells.

16-EA8tailcontacts-.jpg


Deep inside the battery tube are the corresponding set of head contacts

18-EA8headcontacts-.jpg


There is a lot of thoughtful design in the EA8s battery tube. Is has four battery columns each supporting 2 AAs. In the 12 and 6 o'clock positions are the location holes for the tail-cap locating pins to fit into. From each of these location holes there is a groove machined across two of the battery columns. If the batteries need to be fitted in the dark, these grooves indicate to a user which of the four columns have the negative terminal of the battery facing towards you.

17-EA8batterytube1-.jpg


Each of the four battery columns reaches far enough around the battery that it is held in place without needing any of the other columns to be filled. This is illustrated by a single AA being suspended in the top battery column in this photo.

20-EA8batteryheld-.jpg


The threads are very well lubricated out of the box, fully anodised, and have a flawless trapezoid form.

19-EA8threads-.jpg


An excellent feature of the EA8 is that it comes with a holster. There are other 8 AA lights on the market that fail on this point, but the EA8 does not. It is very much like the TM11/TM15 type of holster only scaled down in size.

I am a firm believer in holsters being provided, if nothing else to protect the light however you carry it, so am very glad to see the EA8 has a good one.

03-EA8holster-.jpg


It cannot be avoided any longer, there has to be some comparison to a long standing contender in the 8 x AA light segment of the market, the Fenix TK41. Here they are shown side by side so you can see the size difference. Interestingly, the TK75 weighs in at 534g and the EA8 at 521g (fully loaded with 8 x AA) so there is a negligible difference in weight, but a significant difference in overall size.

15-EA8sidesizeTK41-.jpg




Modes and User Interface:

NITECORE first introduced the two-stage switch and concept of Daily and Turbo modes with the TM11. The EA8 is very similar in this regard as it too has a two-stage illuminated switch. There are some differences in the interface of the EA8.

The EA8's instructions cover this comprehensively, so I will not repeat this verbatim as you can read the instructions here:

...

What I will do is a summary and a couple of observations I have made.

When the batteries are first fitted, the EA8 enters Standby mode.

In Standby, starting OFF – (entering Daily mode)

A half press enters Daily mode. Further half presses cycle through Ultra Low, Low, Medium and High.
- A full press turns the EA8 OFF when running in Daily Mode. (the last used Daily mode is memorised)


In Standby, starting OFF – (entering Turbo mode)

A full press enters Turbo mode. A half press cycles between Turbo and High. After 3 minute Turbo automatically down shifts to High. A half press reinstates Turbo.
- A full press turns the EA8 OFF when running in Turbo Mode


In Daily mode ON – (entering Turbo mode)

A half press and hold for over 1s will enter Turbo mode.


In Daily or Turbo mode ON – (entering Lockout)

A full press and hold for around 1s enters Lockout mode. The EA8 will flash the main LED to indicate it is entering Lockout and then the illuminated switch to indicate the battery voltage (first flashing the whole volts and then the 0.1V)


In Daily or Turbo mode ON – (entering Strobe)

A quick, full double-click enters Strobe/flashing modes. This always enters Strobe first.
To change the flashing mode, fully press and hold the switch for 1s and it will change to SOS. A further full press and hold enters Beacon.

A half or full press turns the EA8 off from Strobe modes.


Exiting Lockout mode –

A Full press and hold for 1s will turn the EA8 into Daily mode and the Low output. The last used daily mode is not remembered when exiting Lockout, it always comes on in Low.


Momentary action starting from OFF in Standby mode–

Using either a half press, or full press for over 1s will be in momentary mode. As soon as the switch is released the EA8 will turn OFF.


The illuminated switch provides three main fucntions:

24-EA8buttonlit1-.jpg


When first installing batteries or entering Lockout mode, the battery voltage is indicated.
When in Standby mode it flashes slowly to act as a locator beacon for the EA8
If the battery is running low, it flashes while the EA8 is on to indicate low battery.

25-EA8buttonlit2-.jpg




Batteries and output:

The EA8 runs on standard AA cells (not 14500 li-ion) cells so can use Alkaline, Ni-Mh or Lithium AAs. Best performance will be with quality Ni-Mh cells.

31-EA88AAs-.jpg


The cell configuration is 4S2P which means the EA8 can actually run with either 4 AAs or the full 8 AAs.

With the minimum 4 AAs fitted

21-EA84AAs-.jpg


And here with all 8 AAs fitted.

22-EA88AAs-.jpg


As the tail-cap is mated with the end of the locator pins have to be lined up with their matching locator holes before screwing the cap fully home.

23-EA8fittingtailcap-.jpg


Output testing was carried out with AA Eneloop Ni-Mh cells.


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 EA8I.S. measured ANSI output LumensPWM frequency (Hz)
Turbo901 (stepping down to 598lm after 3minutes)27.7kHz
High (Turbo mode)59827.7kHz and 285Hz
High (Daily mode)599714Hz and 333Hz
Medium26045Hz is present on the oscilloscope trace but this is not visible
Low84 45Hz is present on the oscilloscope trace but this is not visible
Ultra Low80

Strobe runs at a mix of 25, 18 and 14Hz
Beacon flashes every 2.1s

Due to the automatic downshift from Turbo to High every 3 minutes, I had to reset this during the entire runtime test (and on the odd occasion was not quite a prompt in doing so).

As well as with the full 8 AAs, the output test was also run with just 4 AAs to see how well this would run.

NITECOREEA8runtimeTURBO.jpg


As you can see the heavily loaded 4 AA output means the cells do not manage 50% of the runtime of 8 cells, instead achieving around one third of the Turbo output run time.

Due to the thick battery tube walls, the EA8 has excellent heat-sinking and has no issue running at Turbo for extended periods. During the Turbo runtime test (under a small cooling fan) the maximum temperature recorded was 33ºC. This makes the automatic downshift very frustrating as there is no good reason for it.


As the EA8 has an electronic switch there is parasitic drain to consider. As the EA8 has two different parasitic rates depending on if you are in Standby or Lockout, these have both been measured.

In Standby, the parasitic drain is an average of 3.25mA. This average figure has been measured by recording the standby current as the switch illumination flashes and taking the mean of the readings. At this rate, a fully charged set of 2000mAh cells will be fully depleted in 51 days.

In Lockout the switch illumination is off. The measured drain is 113uA. At this rate, a fully charged set of 2000mAh cells will be fully depleted in 4 years.



The beam

The indoor beam shot shows the very bright hotspot with super smooth spill with no flaws or artefacts.

26-EA8beamindoors1-.jpg


Underexposing the image shows the uneven slightly yellowish corona around the hotspot. This is only noticeable when white wall hunting.

27-EA8beamindoors2-.jpg



As mentioned before, I have to make comparison with the Fenix TK41. For the outdoor beam-shot the first image is of the TK41 and then at the same exposure, the EA8.

Fenix TK41

28-TK41beamoutdoors-.jpg


NITECORE EA8 at the same exposure. The width of the spill appears the same, and the hotpsot very similar though marginally wider on the EA8.

29-EA8beamoutdoors-.jpg


As far as throw goes, using the same equipment to compare them, the TK41 has an estimated beam range of 447m and the EA8 444m.



What it is really like to use…

11-EA8angle2-.jpg


The EA8 brings the size of an 8 x AA powered light down to something very comfortable to hold and compact enough for easy carry.

At just over half a kilogram in weight when fully loaded with Eneloops, the EA8 feels really solid. The impression is one of a very robust light.

The two-stage switch is a clever interface, and being a side-switch your thumb naturally falls onto it making the EA8 a very ergonomic design.

The half-press / full-press interface doesn't always work all that naturally, especially when for daily mode you switch it on with a half press and off with a full press. I've found myself frequently turning it onto Turbo when I meant to use Daily as I've used a full press (having just turned it off that way) to turn it back on. So it gives you a good control method, but one that you may need to think about.

On the original NITECORE models with illuminated two-stage switches, the switch illumination has been very bright. In fact the switch's beacon flash on these models, such as the TM11, is too bright to use on a bedside table. In a dark room it is bright enough to disturb a light sleeper.

The EA8 almost goes too far the other way. The switch illumination is very dim through the opaque black switch cover. The photos shown earlier in the review required long exposures to show the switch lit up. In daylight it is not possible to see the switch illumination and if using turbo, it is also often not possible to see the switch light.

Unfortunately this makes it very difficult to see the battery voltage when putting the light into the Lockout mode.

However, this dim switch illumination is now perfect for use on a bedside table, as the brightness is sufficient only to locate the EA8 and not project a beam of light on the wall.

With a real 900 lumens, the EA8 is the brightest AA powered light I've used and is very impressive. With strong throw and a smooth, bright, usable spill, the EA8 gives you a great all-round beam.

Full power is available even if only running on 4 AAs (be careful if trying to use only 4 Alkalines as they might struggle) making the EA8 very versatile and easy to feed.

Whether exploring caves and treading in the (torchlit) footsteps of our ancestors or just out walking the dog, the EA8 gives you a fist full of light with the ease of AA power.


30-EA8beamsky-.jpg




Test sample provided by NITECORE for review.
 

dougie

Enlightened
Joined
Aug 21, 2006
Messages
523
Location
Jersey
As always a great review of another flashlight. Thanks for your time and effort, it's appreciated! :)
 

shelm

Flashlight Enthusiast
Joined
Dec 8, 2011
Messages
2,047
Thanks for the review as alsways!!

You measured 901 lumens? Amazing :D
 

Mr Floppy

Flashlight Enthusiast
Joined
Feb 19, 2007
Messages
2,065
Oh, I'm a little disappointed that it uses PWM. The EA4 didn't so I'm surprised that this one does. The other disappointing thing is the step down. I was under the impression from Patriot in the regular EA8 thread that it didn't/wouldn't have a step down.
 

InquisitiveInquirer

Enlightened
Joined
Jul 17, 2010
Messages
237
Thanks for taking the time for the photos and in-depth review. It was great. The part about it stepping down after 3 minutes is not great. :shakehead In the other nitecore EA8 thread, patriot, one of the first CPFers to get a hold of the light, did an excellent youtube review where he stated that there was no stepdown from turbo. Does this mean that they released two versions? One with stepdown and one without? This is bizarre, especially when you found the heat only gong up to 33C on turbo. I gotta say i'm somewhat disappointed even though i've not even gotten the EA8 in my hands yet!
 

430Scuderia

Newly Enlightened
Joined
May 9, 2008
Messages
74
Thank you for another excellent review. It appears to me that the EA8 is a bit brighter in your outdoor beam shot compared to the TK41.
May I ask what is the distance from the light to the tree?
 

tickled

Newly Enlightened
Joined
Jun 13, 2011
Messages
145
I have one of these and I cannot detect any PWM using any of the basic methods usually recommended here.
 

herosemblem

Enlightened
Joined
Apr 2, 2011
Messages
355
Location
Yolo, CA
I did not read through the whole 17 page EA8 review, but I came across one part where (perhaps out of context) that seemed to suggest the light stepped down after 3 minutes. Was this using 4 batteries?

My EA8, using 8 batteries, has no stepdown from turbo. Just wanted to be sure. Thanks!
 

tickled

Newly Enlightened
Joined
Jun 13, 2011
Messages
145
May I ask what the Turbo stepping down situation is with yours?
Initially after reading this thread, I watched the ceiling intently while ceiling bouncing this thing and I thought there was a step down but I wasn't sure. I thought my eyes might have been playing tricks on me.

Just now I took a few pictures in manual mode (turbo on, 4 minutes later, manually switched to high) and from looking at the histograms, there doesn't appear to be much of a difference between the first two and a clear difference with the third. I might setup my tripod and try again shortly.

A step down after 3 minutes just would not make sense given the specs and runtimes given by the manufacturer.
 

Patriot

Flashaholic
Joined
Feb 13, 2007
Messages
11,254
Location
Arizona
I can't say enough good things about your reviews SW! I'm completely baffled over the 3m step down however. My light is in the safe without batteries at the moment and I was about to go to bed. This might just keep me awake though.

I'll either check it again tonight or tomorrow night but I have would have trouble believing that my light is different than yours. With that said, mine came in a shipment of 15 lights that were overnighted from China and the first batch into the States, so who knows. I have access to at least one more EA8 from that first batch which I'll be getting my hands on.

I'm honestly a bit annoyed with Nitecore for installing a timed step down that is in no way necessary from a thermal standpoint. At least with a light like the TK75 it's set to 20 min. and by then the light is darn toasty.
 

subwoofer

Flashlight Enthusiast
Joined
May 5, 2010
Messages
2,501
Location
Hove, UK
Thanks for the positive comments :)

Thanks for the review as alsways!!

You measured 901 lumens? Amazing :D

It did indeed manage 901 ANSI lumens (the output at 30s from switch on). The runtime graph shows that this stabilises at more like 870 for most of the run.

Thank you for another excellent review. It appears to me that the EA8 is a bit brighter in your outdoor beam shot compared to the TK41.
May I ask what is the distance from the light to the tree?

To the eye, there is not really any difference, but the TK41 has the tiniest edge on range (again not visible) and the EA8 has the edge on actual output. Where the EA8 really scores over the TK41 is on its size.

The tree is at about 22m and the fence 30m from the camera.

I have one of these and I cannot detect any PWM using any of the basic methods usually recommended here.

The PWM I detected was only noticeable as I use an oscilloscope with the Integrating Sphere to measure exact frequencies. This means I can detect any signs of PWM even if not visible to the eye and can also precisely measure strobe rates.

The EA8 appears to use overlaid frequencies as when changing the time-base on the oscilloscope I found more than one frequency present. With frequencies such as the 27.7kHz (make sure you spot kHz vs Hz) this is not something the eye can detect. Consider that fluorescent lighting flickers at 50Hz and CRT TVs at 25-30Hz so anything above these becomes less and less visible.

I was very surprise to measure a 45Hz frequency on a couple of levels and had to check and recheck my measurements to be sure. Oddly it is not at all visisble and must simply be a slight wobble in the output level rather than a true on/off cycle, otherwise it would be very visible. This is why I specifically mentioned this was not visible.

In actual use of the EA8 I've not noticed any PWM effects, but I report the measured frequencies as these form part of my detailed testing.

PWM, if used correctly, can have positive effects such as maintaining consistent tint at different outputs and a higher perceived brightness for lower power usage, so it is not necessarily bad.

In the EA8 the PWM seems well implemented has not caused any negative effects that I can find.
 

selfbuilt

Flashaholic
Joined
May 27, 2006
Messages
7,005
Location
Canada
Hi subwoofer,

Nice review, very detailed and thorough. I particularly like the great pics, nice job. :)

I am currently testing an EA8, and should have my review posted in a few days.

On the issue the step-down, I can say that mine does indeed step down on Turbo - but by less than 10% of max output. Like yours, my lumen estimates for my sample are very consistent with Nitecore specs. But after the 3min step-down, my sample is still >800 lumens for the rest of the flat-regulated run (i.e., it does not drop down to my Hi level of ~600 lumens). It's odd that there is a difference among samples, and I'm curious as to what others find. :thinking:

On the issue of Pulse-Width-Modulation (PWM), perhaps I can clarify - my EA8 sample is NOT using PWM. What your oscilloscope is presumably picking up is re-occuring signal noise at defined frequencies (which I often observe, but is not PWM). A PM is inbound, so we can discuss that offline. :)

In any case, I am not finding any signficant noise or re-occuring signal on my EA8 sample, above the background noise of my testing equipment. That doesn't mean there isn't some there, but it is not detectable on my sample with my setup, and is certainly not visible.

In any case, hope you don't mind my jumping in here to provide some preliminary results of my sampl. Full circuit details, runtimes and output measures on mine will be coming in my review in a few days.
 

subwoofer

Flashlight Enthusiast
Joined
May 5, 2010
Messages
2,501
Location
Hove, UK
Hi subwoofer,

Nice review, very detailed and thorough. I particularly like the great pics, nice job. :)

I am currently testing an EA8, and should have my review posted in a few days.

On the issue the step-down, I can say that mine does indeed step down on Turbo - but by less than 10% of max output. Like yours, my lumen estimates for my sample are very consistent with Nitecore specs. But after the 3min step-down, my sample is still >800 lumens for the rest of the flat-regulated run (i.e., it does not drop down to my Hi level of ~600 lumens). It's odd that there is a difference among samples, and I'm curious as to what others find. :thinking:

On the issue of Pulse-Width-Modulation (PWM), perhaps I can clarify - my EA8 sample is NOT using PWM. What your oscilloscope is presumably picking up is re-occuring signal noise at defined frequencies (which I often observe, but is not PWM). A PM is inbound, so we can discuss that offline. :)

In any case, I am not finding any signficant noise or re-occuring signal on my EA8 sample, above the background noise of my testing equipment. That doesn't mean there isn't some there, but it is not detectable on my sample with my setup, and is certainly not visible.

In any case, hope you don't mind my jumping in here to provide some preliminary results of my sampl. Full circuit details, runtimes and output measures on mine will be coming in my review in a few days.

Thanks for the input - you set the reviewing standard to aim for on CPF.

Agreed, the output 'noise' on the EA8 is not real PWM, but it is a variation in actual output.

On at least a couple of lights this 'noise' has become visible despite not having the classic PWM trace. I have also challenged the manufacturer of a couple of lights that exhibited exactly this type of oscilloscope trace and did exhibit the effect of PWM without the classic Pulses being visible in the trace. They then said it was a form of PWM they were using.

There is a grey area between lights with absolute flat output and those with classic PWM, which muddies the water. Currently I intend to report on the presence of noise and will try to more clearly differentiate when classic PWM is present.

This 'noise' in some light's output might justify a thread of its own....
 

selfbuilt

Flashaholic
Joined
May 27, 2006
Messages
7,005
Location
Canada
I have also challenged the manufacturer of a couple of lights that exhibited exactly this type of oscilloscope trace and did exhibit the effect of PWM without the classic Pulses being visible in the trace. They then said it was a form of PWM they were using.

This 'noise' in some light's output might justify a thread of its own....
Yes, I have a few manufacturers comment to me that the signal spikes are a result of the "filtering" they are using for PWM. But as the patterns show up on current-controlled lights as well, so it is hard to know their source. I agree that this would be a good topic for the electronics subforum. ;)

At the end of the day, it really comes down to our ability to technically measure versus our ability to visually detect (i.e., any signal of sufficient intensity at low enough frequency can be perceptible as "flicker"). Glad to hear there is nothing visible on your EA8 sample, just like mine.
 

Patriot

Flashaholic
Joined
Feb 13, 2007
Messages
11,254
Location
Arizona
Man, this is really odd. Just ran two tests 5-6 min each and there's zero step down from turbo. I have a buddy with a sister light to mine from the first batch that came in and I'll be able to see his light next mon or tues. I'm guessing that my step down circuit is inoperative/defective unless my friend's light behaves like mine, in which case I'm guessing the first batch was programmed differently. It's really strange to know of three different lights all behaving completely different from one another. SW's light is obviously waaaay conservative with that significant step down while SB's light is only dropping 10-12%. I was struck stupid when I saw your graph last night SW!
 

tickled

Newly Enlightened
Joined
Jun 13, 2011
Messages
145
On the issue the step-down, I can say that mine does indeed step down on Turbo - but by less than 10% of max output. Like yours, my lumen estimates for my sample are very consistent with Nitecore specs. But after the 3min step-down, my sample is still >800 lumens for the rest of the flat-regulated run (i.e., it does not drop down to my Hi level of ~600 lumens). It's odd that there is a difference among samples, and I'm curious as to what others find. :thinking:
The only tool I have to examine this is my camera and I can say my observations are the same as yours. When my EA8 runs on turbo it steps down very slightly after 3 minutes and it's barely perceptible in use and I can only see a tiny difference when looking at image histograms. The step down is nowhere as "low" as the high level-which when compared via histograms-is significantly lower than whatever the step down level is. I have the EA8W which I ordered in mid-March.
 

Patriot

Flashaholic
Joined
Feb 13, 2007
Messages
11,254
Location
Arizona
I think I'll hold off on picking up an EA8W until we've got more information on step down. To be honest, I've lost a bit of interest if that's part of the standard design of the light. It has the capability to run on high continuously without over heating. I won't be able to verify if my light is broken until I get my hand on its sister light next week. Regardless, a 3 min step down, unrelated to thermal condition, pretty much evaporates my initial high praise for the light.
 
Top