Battery Soapbox - I'm Sold on Eneloops

[TheWalkman]

Though a casual user by CPF standards, I'm a longtime rechargeable fan and I'm sold on Eneloops as the best rechargeables ever. I had a very pleasant finding this weekend and wanted to share it with the forum.

Saturday, I decided to refresh/ analyze some Eneloop AAA's and AA's I've had since May of '08. I have two sets of AAA's I use weekly around the year in a Princeton EOS for a couple of hours per week and three sets of AAs for general use - flashlights, portable radios, etc.

I put the batteries in my Maha charger for a refresh and I was absolutely astonished to find the AAA's showed a capacity of ~825 MAh (rated 800) and the AA's showed ~1945 MAh / 2000 rating after nearly two years of use.

I've been using rechargeables since the eighties and I've tried a bunch of brands over the years. I'll pick up a half dozen of whatever the hot brand du jour is - Sanyos, Panasonics, Powerex, etc. but they never seem to live up to my expectations; capacity fades quickly or they won't hold a charge after a year or so.

It always seems when I need a fresh battery, my rechargeable let me down. (Though I'm not a hardcore user by CPF standards - I bought only one new light in the past year - I do take care of my cells.)

For me, the Eneloops do exactly what I want and when I need them to.

What I'm learning is that consistency and reliability are much more important to me than who wins the ultimate capacity shoot-out. A battery may have great specs on paper but when I pull the battery out to use and find it has self discharged or the cells are no longer matched, who cares.

I think Eneloop has the right formula; perhaps they don't have the highest capacity but you can count on them when you need them and they will perform as promised. That's a winning formula for me.

Though I hope there's no need to buy any replacements soon, if anyone asks my opinion, I point them straight to the Eneloop rack.

 

[bthrel]

+1 on the eneloops, I agree 100%, I also like very much the NiZn from PowerGenix :thumbsup:

Brian

 

[noisebeam]

I have four Powerex Imedion AA's (2100mah rated) that I purchased Feb 11, 2008. I have used/abused them weekly charging in a dumb charger the first year and maha 401fs 2nd year. I just got a maha c9000 in late Dec. and ran a BI cycle:

I1: 2116 (Impedance Check Voltage = 1.50)
I2: 2104 (ICV = 1.59)
I3: 2138 (ICV = 1.53)
I4: 2136 (ICV = 1.51)

 

[joe1512]

Amazon has a great deal on them too. You get 8 AAs and 2 AAAs along with a charger and a few C and D adapter shells. All for around 30 bucks. Its how I got started with them.

 

[45/70]

I have four Powerex Imedion AA's (2100mah rated) that I purchased Feb 11, 2008. I have used/abused them weekly charging in a dumb charger the first year and maha 401fs 2nd year. I just got a maha c9000 in late Dec. and ran a BI cycle:

I1: 2116 (Impedance Check Voltage = 1.50)
I2: 2104 (ICV = 1.59)
I3: 2138 (ICV = 1.53)
I4: 2136 (ICV = 1.51)

First let me say that I don't really have anything against Imedions or the other "clones". They have actually been shown to provide a bit more capacity at lower current drain levels. Where the eneloop difference shows up, is when the cells are discharged at a higher rate than the 0.2C standard. If you were to discharge your Imedions at a 1C rate, and then compare that to two year old eneloop's, discharged at that same 1C rate, therein would lie the difference between the two.

Dave

 

[noisebeam]

OK, interesting. I use these nearly exclusively in LED flashlight (L2d) What is the current draw there, probably quite a bit higher than 200, but less than 1000.

 

[computernut]

After a few years of using Energizer rechargeables with flashlights and R/C transmitters, I finally gave up and replaced them all with Duraloops. Sure the Energizers were cheaper and had more 'capacity' I was constantly having bad cells and having to throw them out.

 

[45/70]

OK, interesting. I use these nearly exclusively in LED flashlight (L2d) What is the current draw there, probably quite a bit higher than 200, but less than 1000.

Well, in a 2xAA light, the boost circuit is fairly efficient, but I'd rather imagine that your L2D is pulling at least 1A from the cells at the highest level, probably a bit more.

The loads of most of my applications run 2-3A, as with AA lights for example, I use primarily single cell versions. I use them mostly at max output, but do run them at lower levels sometimes, so I figure the average is around 2A.

A while back someone did a comparison of various LSD cells. One thing that stood out between the eneloops and other LSD cells, was that after 100-150 cycles there was an appreciable drop in capacity of the competitors, compared to the eneloops. The eneloops, as I remember, didn't show this drop until ~250 cycles. It is also significant to note, that eneloops have a slight voltage under load advantage over other LSD cells, as well. This also remained apparent in the cycling tests.

Again, I have nothing against Imedions. I have considered buying some, as sometimes their (or "others") "bang for the buck" ratio is a bit higher. For my applications though (which include other high current drain devices, in addition to flashlights), where I'm pushing the cells harder, I consider the slight advantage of the eneloops to be worthwhile.

Dave

 

[noisebeam]

For what it's worth I have nothing for or against Imedion or Eneloop. When I bought the Imedions it was what was available in LSD at a decent price and at the time didn't even know about cpf and that people even tested batteries to the extent that is done here. (I should have known better )

A few weeks ago I just bought four AAA Eneloop (all started between 785-801mah for new out box using c9000 burn in cycle) and when I need more AA LSD will likely buy Eneloop.

The other batteries I just bought were some Sanyo 2700's - wanting capacity over all (assuming?) longest run time in the L2d. Holding charge doesn't help me as I start with fresh charged and use light until the batteries are dead.

 

[Erasmus]

Eneloops are great batteries indeed. The only drawback I recently discovered, is that they can suffer in low temperatures. I recently moved to Sweden and with temps between -20 and -30 centigrades they seem to run out pretty fast. I guess other NiMH's will have the same problem though.

 

[TheWalkman]

Eneloops are great batteries indeed. The only drawback I recently discovered, is that they can suffer in low temperatures. I recently moved to Sweden and with temps between -20 and -30 centigrades they seem to run out pretty fast. I guess other NiMH's will have the same problem though.

I can't fault Eneloops for that; at those temperatures my internal batteries don't last as long as they once did either! Brrrrrr!

Here's to a hot cocoa for you, Erasmus!

 

[robb01]

Eneloops are the best :thumbsup:

 

[Navin_R_Johnson]

Eneloops are great batteries indeed. The only drawback I recently discovered, is that they can suffer in low temperatures. I recently moved to Sweden and with temps between -20 and -30 centigrades they seem to run out pretty fast. I guess other NiMH's will have the same problem though.

I'm curious if you have discovered a NiMH battery that works better than Eneloops in cold weather? I've not tried any battery in -20 to -30 C, and (like you) wonder if any would actually perform that cold? I have used batteries in cold weather (say 25deg F) and find the Eneloops actually a bit better than other brands. Of the brands I've tried in the cold, the Imedions mentioned in a previous post are by far the worst.

 

[Turbo DV8]

I'm curious if you have discovered a NiMH battery that works better than Eneloops in cold weather?

I wonder how NiZn compares to Eneloops in the cold?

 

[WDG]

I put the batteries in my Maha charger for a refresh and I was absolutely astonished to find the AAA's showed a capacity of ~825 MAh (rated 800) and the AA's showed ~1945 MAh / 2000 rating after nearly two years of use.

The numbers I get pretty much match yours, for Eneloop cells I bought in both 2007 and 2008. I am absolutely sold on Eneloops, too! IIRC, SilverFox did a comparison test somewhere around here that had Eneloops withstanding up to a 10 amp load.

 

[Nil Einne]

Well, in a 2xAA light, the boost circuit is fairly efficient, but I'd rather imagine that your L2D is pulling at least 1A from the cells at the highest level, probably a bit more.

The loads of most of my applications run 2-3A, as with AA lights for example, I use primarily single cell versions. I use them mostly at max output, but do run them at lower levels sometimes, so I figure the average is around 2A.

A while back someone did a comparison of various LSD cells. One thing that stood out between the eneloops and other LSD cells, was that after 100-150 cycles there was an appreciable drop in capacity of the competitors, compared to the eneloops. The eneloops, as I remember, didn't show this drop until ~250 cycles. It is also significant to note, that eneloops have a slight voltage under load advantage over other LSD cells, as well. This also remained apparent in the cycling tests.

Do you remember where those tests on performance after many cycles/cycle lifetime were? I've been looking for the past hour or so but can't find them :-(

 

[45/70]

Do you remember where those tests on performance after many cycles/cycle lifetime were? I've been looking for the past hour or so but can't find them :-(

Nil, all I can tell you is that I'm about 90% certain that it was SilverFox that did such a test here on CPF. I've also seen similar results on a camera, or photography site. Which one? Sorry, I'm not going to be able to help you there, as it was some time ago.

If I have time, I'll try to find Tom's thread. I've been really busy here the past few days though, so I'm not going to promise anything.

Dave

 

[was.lost.but.now.found]

Do you remember where those tests on performance after many cycles/cycle lifetime were? I've been looking for the past hour or so but can't find them :-(

http://www.candlepowerforums.com/vb/showthread.php?t=79302

 

[45/70]

Thanks, was! :thumbsup:

That familiar thread does show the current under load advantage of the eneloops. The thread I'm thinking about however, was more a comparison of LSD cells and their measured performance over many cycles though.

Dave

 

[fishinfool]

Diamonds......oops Eneloops are Forever!