Why Eneloops??

[Wassernaut]

:thinking: Could someone explain in short and simple terms the advantage of Eneloop batteries? I hear so much about them, but haven't seen any info on what makes them radically different or better. I use Li-Ion primaries and rechargables and still use some Ni-Mh's. Thanks - Larry

 

[Norm]

I used to use 2500 mA NiMh batteries in my blood pressure machine,which I use constantly for dialysis the NiMh batteries would last 2 months the Eneloops are up to 4 months and still going strong even though they are lower capacity, with very little self discharge they definitely outlast ordinary NiMh batteries. Does this sound like an advertisement?
Norm

 

[leeleefocus]

They seem to be alot more robust than other normal cells and they can hold there voltage very well under quite heavy loads.

 

[Fallingwater]

The main difference is low self discharge.

An ordinary NiMH discharges fairly quickly on its own, even if left unused. The official data is 30 to 60% discharge every month depending on brand and model, but I've seen some dump about 90% of their capacity in a week.

LSD cells such as Eneloops are supposed to keep 85% of their capacity in a year. I don't know if that claim is actually true, but it's proven that their self-discharge is much, much lower.

I myself use two LSD cells (Varta Ready2Go AAAs) in my Palm IIIx, and they are much more suited to it than the old ordinary NiMH cells I used before.

 

[NiOOH]

Yes, low self-discharge is the key. Ordinary, NiMH cells were less suitable for applications that are not used frequently. Low self discharge cells, like Eneloops, can trully replace single use ones in al applications.
On top of that Eneloops turned out to be very good in handling high discharge currents.

 

[macdude22]

The LSD cells seem to be very adept at high current applications, even more so than "classic" NiMH cells. I've noticed my flash seems to charge a second or two quicker since I started using Hybrids in the camera instead of some other NiMH cells. Plus they are great in things I don't use too often but when I do I want them charged, like the camera, GPS, Portable Radio, etc.

 

[LA OZ]

These eneloops technology will replace the common NiMH, period.

 

[Fallingwater]

As far as I know, all NiMH cells that don't try to squeeze as much capacity as possible in their casing are more adept at high capacity discharges and more tolerant of abuse.
There's a reason, after all, why RC NiMH cells are never super-high-capacity ones (AAA packs are all 600 to 700mah despite the latest cells getting to 1ah).

I hazard the guess that ordinary 2ah AAs would probably do just as good as Eneloops in high-discharge applications.

LAOZ: I wouldn't be so sure. There are applications where +50% capacity is preferable to low self discharge.
The status will probably invert soon (more LSD sold than ordinary NiMH), but unless they manage to come up with 3ah LSD cells, ordinary ones will still have their place.

 

[Wassernaut]

Can Eneloops be charged on standard Ni-Cad/Ni-Mh chargers or do they need a special charger? I have several switchable (Ni-Cad/Ni-Mh) chargers in use now. Thanks - Larry

 

[Windscale]

Yes, you can charge them using an ordinary NiMH charger (not sure about Ni-cad chargers). Since I started using them I have given away most of my non-LSD ones to friends. Eneloops are really that good. You won't regret using them.

 

[PlayboyJoeShmoe]

What they said mostly.

In my case I run a Garmin Etrex Legend GPS in my truck each day. It is a 2AA model. I used to run 2500 and the ran good. Then I started getting only part day runs, or it wouldn't come on at all.

Since changing to a mix of Eneloop, Hybrid and Kodak LSD cells, I've only had one problem that SEEMED to be heat related. MAY also have had something to with charging them.

Anyhow with 2500s I would charge weekly. Now I'll use two weeks worth of LSD before charging and I use slowish 4-6 hour charging.

And after two or three weeks I still get 13 hour runtime.

 

[Marduke]

Can Eneloops be charged on standard Ni-Cad/Ni-Mh chargers or do they need a special charger? I have several switchable (Ni-Cad/Ni-Mh) chargers in use now. Thanks - Larry

Yes, but you have to question if the chargers you have are good for even normal NiMH cells. The basic, cheap, simple timed charger will hurt any NiMH cell in the long run. Say a cell is most full, and only needs topped off. You stick that cell on a simple timer charger, and it puts it through an 8 hour charge cycle when maybe it only needed 1 hour. 7 of those hours were spent heating the cell up, permanently damaging it. This means that it will take less of a charge in the future, and not handle as many recharge cycles in total. Even a cheap, independent channel voltage peak sensing charger is better than most anything you'll find in your local supermarkets or Walmart.

 

[UnknownVT]

:thinking: Could someone explain in short and simple terms the advantage of Eneloop batteries? I hear so much about them, but haven't seen any info on what makes them radically different or better.

eneloops (along with RayOVac Hybrid, Kodak Pre-Charged, Uniross Hybrio ) are LSD (Low Self-Discharge) batteries.

They have a separator(correction edit) to help hold their charge longer - retaining as much as 85% for a year.
Whereas regular high capacity NiMH seem to lose almost all of their charge on average in about 3 months.

These LSD batteries generally have lower capacity ~2000-2100mAh - compared to more current NiMH rechargeables ~2500-2700mAh.

LSD batteries are useful if one does not use the equipment/flashlight regularly, and need them to be ready for use.

Whereas if the equipment/flashlight is used extensively over a period of less than a month - then the regular higher capacity NiMH still show advantages.

SilverFox says the crossover point when compared to 2700mAh batteries is about one month.

I really favor the LSD - I use the Kodak Pre-Charged -

However the lower capacity of LSD does reveal itself when in high discharge/current demand devices.

Last night I was using the sensor cleaning on my dSLR - the manual warns to use fully charged batteries.

Using fully charged Kodak Pre-Charged 2100mAh the camera sounded the low battery warning signal in less about 10 secs - despite the fact mine were recently fully charged - and when in the regular camera mode the battery indicator shows full (my dSLR is well known to be battery sensitive/fussy).

Whereas using 2500mAh Sakar/Digital Concepts NiMH that I charged on Sept/15 - over 2 weeks ago - the sensor cleaning function went for over half minute without any signals.

So this is one case where the higher capacity regular NiMH performed better than the LSD.

Note: Chevrofreak tested the Kodak Pre-Charged, and seems to think well of them -
ref: Post #15 in this thread - My Eneloops charge to and hold a higher voltage than other LSD's
and - Posts #13 and #14 in new Kodac "Pre Charged" NiMH batteries?

 

[Norm]

They have built-in circuitry to help hold their charge longer - retaining as much as 85% for a year.

Please tell us more about the function of this circuitry, I thought their low self discharge was just due to a different chemical make up.
Norm

 

[UnknownVT]

Please tell us more about the function of this circuitry, I thought their low self discharge was just due to a different chemical make up.

My apologies - perhaps I've been loose with my terminology - it's a "separator" - here's the write up at the Wikipedia (it's section 5.1.1 Low Self Discharge Batteries on the general NiMH page)

QUOTE:
Low Self Discharge Batteries
A new type of nickel-metal hydride battery was introduced in 2006 that claims to reduce self-discharge, and therefore lengthen shelf life. By using a new separator, manufacturers claim between 70 to 85% of capacity is retained after one year, when stored at 20 degrees Celsius (68F). These cells are marketed as "ready-to-use" rechargeables, and are targeted towards typical consumers who use their digital cameras only a few times a year. Besides the longer shelf life, they are otherwise similar to normal NiMH batteries of equivalent capacity, and can be charged in typical NiMH chargers. Some brands that are currently available on the market (Sep 2007) are Accupower Acculoop, Ansmann MaxE range, Duracell Pre-charged, Gold PeakReCyko, Kodak Pre Charged, Nexcell EnergyOn, Panasonic R2, Rayovac Hybrid, SanyoEneloop, Sony CycleEnergy, Titanium Power Enduro, Uniross Hybrio, Vapextech Instant and VARTA Ready2use. These appear to be available in AA and AAA sizes only, and have less capacity (2000~2100mAh in AA) than the current generation of high-capacity cells (2800mAh, AA). As there are only two or three manufacturers of these new type of cells (Sanyo, Panasonic, Yuasa-Delta) most of these brands are rebranded OEMs.
UNQUOTE

 

[Norm]

Thanks Vincent I didn't know about any of that
Norm

 

[UnknownVT]

Thanks Vincent I didn't know about any of that

I'm still learning too -

Thomas Distibuting has a nice write up on Sanyo eneloops .

which I think contains the eneloop Technology page from the eneloop Europe site

Here's a thread I've just come across over at dpReview -

Low self-discharge AA comparison (19 messages)

 

[Turak]

The LSD improvements are 'just a bit' more than just a change in the separator.

The following is what Sanyo indicates they changed for the Eneloop batteries....

-----------------------------------------------------------------
How was the self-discharge reduced?

Modern Ni-MH batteries consist of two metal stripes ( anode and cathode ),
which are separated by a non-conductive porous plastic foil ( separator ).
These three stripes are laid on top of each other and are winded to a coil.
This coil is put in a metal can and immersed with a liquid ( electrolyte ).
Then the metal can is closed with a cap.

The self discharge of Ni-MH batteries is caused by three main reasons:

• the chemical decomposition of the cathode,
• the natural disaggregation of the anode,
• Impurities of the anode.

Now, how could the self-discharge in the eneloop been reduced?

The chemical decomposition of the kathode has been reduced substantially by the use of a new superlattice alloy.
As an additional benefit the superlattice alloy increases the electrical capacity of the battery and reduces the internal resistance, which allows higher discharge currents.
Another advantage of the reduced decomposition of this alloy is the fact, that less Cobalt is needed to stabilize the alloy.
The anode has been strengthened by another new material, which reduces the natural disaggregation.
Additionally the separator and the used electrolyte have been optimised for low self discharge of the eneloop.

-----------------------------------------------------------------

Here is the web site;

http://www.eneloop.info/home_en.html

Click on ... 'What's Eneloop' and then and then 'Technology'.

 

[UnknownVT]

The LSD improvements are 'just a bit' more than just a change in the separator.
The following is what Sanyo indicates they changed for the Eneloop batteries....
Here is the web site;
http://www.eneloop.info/home_en.html
Click on ... 'What's Eneloop' and then and then 'Technology'.

That's cool - we must be looking at the same web page at about the same time :laughing:

 

[Stromberg]

Eneloop users: do you recommend fast chargers and if so, what is the optimal time to charge Eneloop AA's full? I have couple choices: one that charges in two hours and the other charges in half an hour. Latter one is equipped with cooling fan and battery temperature control.