Battery Soapbox - I'm Sold on Eneloops

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.

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

Brian

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)

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.

noisebeam said:

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)

Click to expand...

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

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.

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.

noisebeam said:

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.

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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

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.

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.

Erasmus said:

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.

Click to expand...

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!

Eneloops are the best :thumbsup:

Erasmus said:

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.

Click to expand...

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.

Navin_R_Johnson said:

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

Click to expand...

I wonder how NiZn compares to Eneloops in the cold?

TheWalkman said:

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.

Click to expand...

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.

45/70 said:

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.

Click to expand...

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 Einne said:

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 :-(

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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

Nil Einne said:

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 :-(

Click to expand...

https://www.candlepowerforums.com/threads/79302

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