Do I need to trash my AA batteries in Nitecore EA4

I am sorry for my bad English before writting this question

I have got nitecore EA4 recently.
To play with EA4, I use my E-keep AA batteries(this is eneloop type battery. this is known as good battery in Japan,Taiwan brand)
I turned it for one hour for test.
And I found that the rubber switch was popped up like a balloon.
It seemed be exploded soon!
It means the batteries produce gas.
Acutally I had similar experiece when I used ThruNite Neutron series.
Do I need to trash my AA batteries?
Anybody know what is the gas name?

Are you sure you didn’t just overheat it?

My EA4 was left on full to test it and I left it running for 1.5hrs and my button is fine. I’m using Hybrio LSD’s

Read this thread over at CPF:**NEW**-Nitecore-EA4-Pioneer-(4*AA-860lm)&p=4132431&viewfull=1#post4132431

Two or Three reported issues like you have experienced, but I'm not sure what has been done about it. If you just got the light, send pics directly to your dealer and to Nitecore.

Seems that the flashlight got hot due to your testing and working continuously for one hour.
Another member had a similar problem with the rubber button when he left the EA4 in his car where temperature was quite high.

Fact is that Nitecore has to redesign this rubber button on the EA4.
Besides the fact that heat is obviously affecting it, the led beneath is almost invisible when lit.

Thank you for you guys opinions.
Yes I tailstanded it for one hour…
Compare to Nitecore P25,I thought that EA4’s heat treatment was better to touch.(both are on high mode, EA4 doesnt get hot for one hour. it was just warm.

Actually the heat design of the EA4 is bad. The LED gets very hot while the body stays rather cool -> no good heat transfer.

I heard people suggested to maky tiny holes with a needle in the rubber button to release the pressure..

(I know this is a little off topic, but I have never seen these E-keep batteries here in Japan, and if they are, very unlikely, they are not popular here)

they might be re-branded eneloops, but I`ve never heard of E-keep.

Now I am testing it on mid(280 lumen) for 30 min…
It is getting gas again. body is just cold.
so it would not heat problem?. i am not sure
I will test with fresh akaline batteries

Wow, that does not look healthy. ;_;

Have you heard of Lexel brand?

no, never seen lexel brand batteries here… (nor E-keep)

Does the cap deflate after the lights been turned off?

No. Because I removed tailcap at once when I saw it
Ah you give a idea.
I will not remove tailcap until torch cool down.

Anyways…my old batteries seem be in not good condition.
I can’t charge one battery with sysmax i4 charger after using in EA4
Its voltage is 0.918v
———>the voltage rises to 1.1v next day.I can charger it.
EA4 tortured AA batteries.

I am testing EA4 with akalne batteries now
It has passed 43 minutes since turned on.
rubber cap inflates a little as you see… that is accpetable for now.

It sounds like a heat buildup problem. I wonder what would happen if you pricked a tiny pinhole in the cap? It sound funny, but it is almost as if your EA4 is too waterproof. Heat expands air, and it is not escaping from your torch, which is causing the switch to act as a hot air balloon. The rubber compound chemistry of you cap could also be at fault.

So far I haven't had this issue with mine. I just put freshly charged eneloops in and I'm going to let it run until the light shuts off. I'll report back

Maybe NE1 knows FT links for suitable heat transfer paste?

i want buy thank

I am afraid of making hole at cap :slight_smile:

Test seems be failed…
EA4 with Aklaline batteries runtimes is not so good.
It stepped down before 60 minutes
And cap doesn’t inflate much
I should buy New eneloop batteries for test…

Only time I’ve seen a rubber switch cover bulge is when I ran down a single AA to completely drain an alkaline cell. Towards the end of AA’s life, gases escaped and forced the rubber switch cover up and I had hard time unscrewing tail cap, but when I did the bulge disappeared… foolish to do but I was foolish at the time :confused:

Apprarently, a select few of the EA4’s rubber switch covers are of a different composition? Only stretch one way?

Test Results: At 1 hour 30 minutes with regular eneloops, my low battery indicator is flashing fast, but no bulge on the rubber switch boot.. EA4 output has dimmed considerably at 1 hour 35 minutes. At this point I shut the light off

I haven't tested mine too thoroughly in terms of total continuous run time, but have ran it for ~15 minutes repeatedly, without any problems.

The LED is kind of useless while the light is on.

Vs the same size, about almost the same output the EA4 warns up much faster than the fandyfire rook. This could be because the driver is producing more heat, or if the heat dissipation on the ea4 is better. Not sure which.

I'll do a long 1hour+ test this weekend.

it is funny this being mentioned as I have had this happen once to me. It was with a Fenix using 2 AA and the tail switch cover got huge. I discontinued use of those batteries and put another set in and never a problem. I felt at the time it was a faulty battery ( rayovac NiMH) and seemed to confirm after changing .