I was told to NOT use Eneloops..

Status
Not open for further replies.

lightseeker2009

Enlightened
Joined
Jul 29, 2009
Messages
681
As some of you might recall, I had teething problems with my Fenix FD45. My batteries could not supply enough oomph for the flashlight at 900 lumens.
While I posted the problem here, I also emailed Fenix.

I just got a mail back that they do not recommend the usage of Eneloops in their lights. They claim the Eneloops releases a gas, that can corrode the flashlight, since it is waterproof and the gas cannot escape.
How true is this?

They recommended that I should rather buy this: https://www.fenix-store.com/aa-tenergy-ni-mh-rechargeable-batteries-4-pk-in-case/
 

WalkIntoTheLight

Flashlight Enthusiast
Joined
Jun 18, 2014
Messages
3,967
Location
Canada
They're full of s**t. Eneloops are the best NiMH cell you can buy. They'll only vent gas if they are overheated, as will all NiMH cells. Those Tenergy cells may be okay, but beware of buying high-capacity cells like that. They probably won't last long, and they'll develop high internal resistance that will prevent them from working in high-power lights.
 

NoNotAgain

Flashlight Enthusiast
Joined
Jan 25, 2014
Messages
2,364
Location
Blue Ridge Mountains, VA
The only NiMH batteries I e had that fecaled the bed have been the Tennergy AA NiMH cells.

I've got I believe all three generations of Eneloops, and all still charge and hold a charge.

I've got two Fenix TK41 lights powered by Eneloops. One with the XM-L emitter and the other with the XM-L2.
 

lightseeker2009

Enlightened
Joined
Jul 29, 2009
Messages
681
I agree guys. Just strange that a big company is saying that!
Case in point. I own a TK40 for many years now. Stoked with Eneloops all the time. There is no rust!
 

ven

Flashaholic
Joined
Oct 17, 2013
Messages
22,533
Location
Manchester UK
I would like to think someone new on their 1st day at Fenix answered your question(wrongly). Otherwise its very worrying.....................
 

ChrisGarrett

Flashlight Enthusiast
Joined
Feb 2, 2012
Messages
5,725
Location
Miami, Florida
Actually, there's some truth to that. Back 4-5 years, a few of us had problems with the NiteCore EA4 heating the NiMH batteries up, creating pressure and blowing up the rubber switch boot like a balloon.

Here's a tip, don't design a light that heats the batteries up to the point that they vent gas.

Problem solved.

That being said, my SWM D40A CW at 960LM doesn't get them that hot.

Chris
 

WalkIntoTheLight

Flashlight Enthusiast
Joined
Jun 18, 2014
Messages
3,967
Location
Canada
Actually, there's some truth to that. Back 4-5 years, a few of us had problems with the NiteCore EA4 heating the NiMH batteries up, creating pressure and blowing up the rubber switch boot like a balloon.

Here's a tip, don't design a light that heats the batteries up to the point that they vent gas.

Yes, I have only had an issue with Eneloops overheating in one of my AA lights. It's a 4sevens Quark, and it has awful efficiency on turbo. The driver just heats the whole light up so it's way too hot to touch. I ruined a couple of pairs of Eneloops in it, before I clued in. Maybe it's just a bad light, or a bad design.

All my other AA lights are fine. They get hot, but not so hot they can ruin cells.

My rule of thumb is that if a AA light gets too hot to touch, it's probably hurting your NiMH batteries. Lithium-ion can take a bit more heat, and those flashlight designs usually have thermal control anyway.
 

JoeRodge

Newly Enlightened
Joined
Oct 8, 2017
Messages
133
Are these same gases not present in the Tenergy cells? Is it not convenient it's the one they sell on their site? Those aren't LSD either.

"Tenergy is a leader in Ni-MH cell production. When compared to other cells, these Tenergy cells have 15% more capacity than 2000mAh cells, 25% more than 1800mAh cells and a whopping 40% more capacity than 1600mAh cells!". -- Duuuude, no waaaay! Math!
 
Last edited:

chillinn

Flashlight Enthusiast
Joined
Jul 19, 2014
Messages
2,527
Location
Mobjack Bay
Actually, there's some truth to that. Back 4-5 years, a few of us had problems with the NiteCore EA4 heating the NiMH batteries up, creating pressure and blowing up the rubber switch boot like a balloon.

Here's a tip, don't design a light that heats the batteries up to the point that they vent gas.

Problem solved.

I did not know the switch boot could do that until it happened to me in a light pulling about 1.2A with 2xAA eneloops, the cells do get hot in this application. The thing is, I found the light like that one morning a night after using it... the venting and ballooning happened while I was not using it. I thought the boot was toast, but opening the light immediately released the pressure, boot returned to normal size and function.
 

magellan

Honorary Aussie
Joined
Feb 3, 2014
Messages
5,003
Location
USA
Yeah, I'll add my two cents here. What the hell are they talking about?

I'd have told them that a light that has any problem at all with Eneloops is one I don't want to own.
 

magellan

Honorary Aussie
Joined
Feb 3, 2014
Messages
5,003
Location
USA
They're full of s**t. Eneloops are the best NiMH cell you can buy. They'll only vent gas if they are overheated, as will all NiMH cells. Those Tenergy cells may be okay, but beware of buying high-capacity cells like that. They probably won't last long, and they'll develop high internal resistance that will prevent them from working in high-power lights.

Right. My experience is that Tenergy batteries have improved over say, 3 or 4 years ago, no doubt in an attempt to take market share, but are they as good as Eneloops? Not too likely. But I'm pretty sure what the results would be if HKJ tested them side by side.
 
Last edited:

ChrisGarrett

Flashlight Enthusiast
Joined
Feb 2, 2012
Messages
5,725
Location
Miami, Florida
I did not know the switch boot could do that until it happened to me in a light pulling about 1.2A with 2xAA eneloops, the cells do get hot in this application. The thing is, I found the light like that one morning a night after using it... the venting and ballooning happened while I was not using it. I thought the boot was toast, but opening the light immediately released the pressure, boot returned to normal size and function.

I may be a drunk, but I'm a drunk with a good memory.

Chris
 

WalkIntoTheLight

Flashlight Enthusiast
Joined
Jun 18, 2014
Messages
3,967
Location
Canada
I did not know the switch boot could do that until it happened to me in a light pulling about 1.2A with 2xAA eneloops, the cells do get hot in this application. The thing is, I found the light like that one morning a night after using it... the venting and ballooning happened while I was not using it. I thought the boot was toast, but opening the light immediately released the pressure, boot returned to normal size and function.

It's the heat, not the current. The Zebralight SC5 pulls 5 amps from a good AA, and I've never had a problem with it hurting Eneloops. Bad light designs that overheat will hurt AA batteries (any brand).

If Fenix is saying their FD45 overheats and causes Eneloops to vent gas, I'd skip that model.
 

MrAl

Flashlight Enthusiast
Joined
Sep 9, 2001
Messages
3,144
Location
New Jersey
Hello,

Beware the company that says, "The other product is no good, buy from us instead". They all say that :)

I would use it with Eneloops, then check it every three months for any signs of damage inside. After a year or two i would write back to the company and tell them they were wrong.

I dont think they realize what they are saying. They are saying that their flashlight does not work with Eneloops. That's a serious drawback. How about asking about other cells like Kodac low self discharge, or any other low self discharge. See what they say.
 

lightseeker2009

Enlightened
Joined
Jul 29, 2009
Messages
681
Hello,

Beware the company that says, "The other product is no good, buy from us instead". They all say that :)

I would use it with Eneloops, then check it every three months for any signs of damage inside. After a year or two i would write back to the company and tell them they were wrong.

I dont think they realize what they are saying. They are saying that their flashlight does not work with Eneloops. That's a serious drawback. How about asking about other cells like Kodac low self discharge, or any other low self discharge. See what they say.

It is strange to me that they have not recommended their own 1600mah lithium 14500 1.5v batteries.
 

NoNotAgain

Flashlight Enthusiast
Joined
Jan 25, 2014
Messages
2,364
Location
Blue Ridge Mountains, VA
It is strange to me that they have not recommended their own 1600mah lithium 14500 1.5v batteries.

That might be because the FD45 can't handle the increased voltage of the 14500 lithium battery.

Even if the light were wired for a 2S2P configuration, the 14500 would put out 8.4 volts, probably frying the driver.

In Fenix' product description, they list runtimes and lumen output based on four 2500 mAH NiMH batteries. To me that would indicate Eneloop Pro batteries.
 

lightseeker2009

Enlightened
Joined
Jul 29, 2009
Messages
681
That might be because the FD45 can't handle the increased voltage of the 14500 lithium battery.

Even if the light were wired for a 2S2P configuration, the 14500 would put out 8.4 volts, probably frying the driver.

In Fenix' product description, they list runtimes and lumen output based on four 2500 mAH NiMH batteries. To me that would indicate Eneloop Pro batteries.

No. Even though they are 14500's, they are 1.5v and not 3.7v. it is in fact recommended on the retail box of the light. Fenix ARB-L14-1600u li-ion. If they were not just 1600mah I might have bought a set.

Edit: https://www.fenix-store.com/fenix-arb-l14-1600u-usb-rechargeable-li-ion-14500-battery/
 
Last edited:

NoNotAgain

Flashlight Enthusiast
Joined
Jan 25, 2014
Messages
2,364
Location
Blue Ridge Mountains, VA
No. Even though they are 14500's, they are 1.5v and not 3.7v. it is in fact recommended on the retail box of the light. Fenix ARB-L14-1600u li-ion. If they were not just 1600mah I might have bought a set.

Edit: https://www.fenix-store.com/fenix-arb-l14-1600u-usb-rechargeable-li-ion-14500-battery/

Read the spec sheet for the FD45 light. The only two batteries listed are AA alkaline and AA NiMH.

When you read further about the specs, the output, both lumens and run time are based on a 2500 NiMH battery.

The cell you've linked to should only be charged by the USB internal charger.

Further reading of the 1600U battery specifications,Fenix doesn't recommend this cell in the FD45 light.
 
Last edited:

mattheww50

Flashlight Enthusiast
Joined
Jun 24, 2003
Messages
1,048
Location
SW Pennsylvania
The driver is far more likely to heat up the battery tube than the batteries are. One of the features of NiMh and NiCd sells is remarkably low internal resistance. That is what allows them to deliver so much current from such a small package. I've 'thumbnailed' the Internal resistance of a relatively new Eneloop AA cell at about .03 ohms. So at 5 amps, the battery itself is dissipating a whopping .75 watts. The driver however is probably dissipating close to 10 watts at 5 amps from a pair of AA's. You don't need to a genius to understand where the heating is coming from. The same designs that conduct large amounts of current from the batteries to the driver can also conduct large amounts of heat back to the batteries. Good conductors of Electricity are also very good thermal conductors as well.
 
Status
Not open for further replies.
Top