# Why Eneloops??



## Wassernaut (Oct 4, 2007)

: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


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## Norm (Oct 4, 2007)

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


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## leeleefocus (Oct 4, 2007)

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


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## Fallingwater (Oct 4, 2007)

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.


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## NiOOH (Oct 4, 2007)

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.


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## macdude22 (Oct 4, 2007)

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.


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## LA OZ (Oct 4, 2007)

These eneloops technology will replace the common NiMH, period.


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## Fallingwater (Oct 4, 2007)

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.


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## Wassernaut (Oct 4, 2007)

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


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## Windscale (Oct 4, 2007)

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.


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## PlayboyJoeShmoe (Oct 4, 2007)

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.


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## Marduke (Oct 4, 2007)

Wassernaut said:


> 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.


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## UnknownVT (Oct 4, 2007)

Wassernaut said:


> :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?


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## Norm (Oct 4, 2007)

UnknownVT said:


> 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


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## UnknownVT (Oct 4, 2007)

Norm said:


> 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 Peak__ReCyko__, __Kodak__ Pre Charged, __Nexcell__ EnergyOn, __Panasonic R2__, __Rayovac__ Hybrid, __Sanyo__Eneloop__, __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


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## Norm (Oct 4, 2007)

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


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## UnknownVT (Oct 4, 2007)

Norm said:


> 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)


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## Turak (Oct 4, 2007)

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'.


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## UnknownVT (Oct 4, 2007)

Turak said:


> 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:


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## Stromberg (Oct 5, 2007)

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.


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## SilverFox (Oct 5, 2007)

Hello Stromberg,

The two hour charger would be great.

Tom


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## Wassernaut (Oct 5, 2007)

*Man!!! Good Grief!!! Good Goobly Gooop!!!* I've learned more on this thread than I ever thought I would. Thanks to all for adding your knowledge to the list. You are what makes CPF such a great place for noobs like me. - Larry


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## Fallingwater (Oct 5, 2007)

Stromberg said:


> 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.


The two hour one.
Everything that charges in less than one hour is giving the cells a beating. 15 minute chargers are practically a torture for them.


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## PlayboyJoeShmoe (Oct 5, 2007)

The two chargers I am using for LSD batteries are the one that came with 4 Eneloops and the Duracell one that has charge indicators for 4 cells.

Both seem to take between 4 and 7 hours, and no bad stuff seems to happen if I leave them in the chargers overnight.

I have a 10 bay AA/AAA charger that is QUITE slow and a C Crane Quick Charger but I use those mainly for regular NimH.

My Energizer 15 minute charger never touches my LSD batteries!!!!


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## Stromberg (Oct 6, 2007)

Thank you all for good advices. I'll stay away from those "hyper fast" chargers.


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## Yenster (Oct 6, 2007)

Regarding the chargers, not too fast, but not too slow either. By this, I mean that some of the 'overnight' chargers can be bad too. That's because they're simply timed chargers that don't detect the actual charge state of the battery...and they just keep charging even if they're full. I use a charger that has a red LED when charging, and it turns green when the batteries are full and stops charging. And the LED will quickly turn green if I put in charged batteries to protect them from over-charging. 

And as for 'fast' chargers, I think some current (amps) numbers would help determine that aspect. I use a 500mA charger, which is labeled 'rapid' but it's really just a little faster than 'overnight'. It charges in about 4 hours which won't harm the batteries. I think anything over 1 amp is bad.

BTW, I use Rayovac Hybrids (they're just like Eneloops).


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## UnknownVT (Oct 6, 2007)

Yenster said:


> Regarding the chargers, not too fast, but not too slow either. By this, I mean that some of the 'overnight' chargers can be bad too. That's because they're simply timed chargers that don't detect the actual charge state of the battery...and they just keep charging even it they're full.
> I think anything over 1 amp is bad.


 
This is probably correct for eneloops which are rated at 2000mAh - so 1Amp = C/2. 
But it depends on the capacity of the (NiMH) battery.

From the Wikipedia 5.1.1 Low Self Discharge Batteries 
"_Besides the longer shelf life, they are otherwise similar to normal NiMH batteries of equivalent capacity, and can be charged in typical NiMH chargers."_

I found this very useful document over at Duracell -
Ni-MH Technical Bulletin Collection - Download PDF (only about 1/2Mb) -
on page 14 -

_"*Charge Rate *...* Termination Technique*_
_1C to C/2 ......... Voltage or temperature based_
_C/2 to C/3 ........ Voltage based_
_C/3 to C/10 ...... Not recommended_
_C/10 and below . Time limited_​ 
_Table 6.3.1 Recommended charge termination techniques_​_for particular charge rates."_

(Note: my highlighting in Red)

Notice the "Not recommended" range of C/3 to C/10 - 
so for eneloops rated at 1900(min) to 2000mAh 
- the approx range *to avoid* is 
190 to 667 mA charge currents.
(doesn't mean one can't use these, or they won't work - 
they're just not as reliable for detecting full charge and avoiding possible damage)

Comments?


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## Yenster (Oct 6, 2007)

It seems just about all off-the-shelf chargers are in the range C/3 - C/10, including ones from Duracell. So I wonder why it's not recommended. That pdf isn't really clear on that.


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## snipinglight (Oct 6, 2007)

Wassernaut said:


> :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


 
Low discharge rate over long periods, but suffer on capacity


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## UnknownVT (Oct 6, 2007)

Yenster said:


> It seems just about all off-the-shelf chargers are in the range C/3 - C/10, including ones from Duracell. So I wonder why it's not recommended. That pdf isn't really clear on that.


 
Have to be a little diligent/patient to find the reasoning -
Page 13 in the pdf document - the separated section under 6.2.1 Timed Charge - 
I think they've lost the header for this section, which should have been - 
*6.2.2 Voltage Drop (-DV)*

"_Voltage drop is widely used with nickel-cadmium_
_batteries. With this technique, the voltage during_
_charge is monitored and the charge is terminated_
_when the voltage begins to decrease. This approach_
_can be used with nickel-metal hydride batteries, but_
_as noted in Section 6.1, the voltage drop of the nickelmetal_
_hydride battery is not as prominent as that of_
_the nickel-cadmium battery and may be absent in_
_charge currents below the C/3 rate, particularly at_​_elevated temperatures. The voltage sensing circuitry_
_must be sensitive enough to terminate the charge_
_when the voltage drops, but not so sensitive that it_
_will terminate prematurely due to noise or other_
_normal voltage fluctuations. A charge rate of 1C and_
_a 5 to 10 millivolt per cell drop is recommended for_
_the nickel-metal hydride battery with a backup temperature_
_cutoff of 60°C (140°F). A top-up charge is_​_not necessary with this charge termination method_."

So that's why not below C/3.

Combine that with this section (on Page 15)

*6.3.2 Low-Rate Charge *(»12 hours)
"_Charging at a constant current at the C/10 rate_
_with time-limited charge termination is a convenient_
_method to fully charge nickel-metal hydride batteries._
_At this current level, the generation of gas will not_
_exceed the oxygen recombination rate. The charge_
_should be terminated after 120 percent charge input,_​_or approximately 12 hours for a fully discharged battery._
_Excessive overcharging should be avoided, as it_​_can damage the battery."_

and this explains why not above C/10.

To further corroborate this from the BatteryUniversity.com 
Charging nickel-based batteries
(about 2/3 down the page)

"_*Charging nickel-metal-hydride*_

_Nickel-metal-hydride chargers require more complex electronics than nickel-cadmium systems. To begin with, nickel-metal-hydride produces a very small voltage drop at full charge and the NDV is almost non-existent at charge rates below 0.5C and elevated temperatures. Aging and degenerating cell match diminish the already minute voltage delta further. This makes full charge detection difficult._

_A nickel-metal-hydride charger must respond to a voltage drop of 8-16mV per cell. Making the charger too sensitive may terminate the fast charge halfway through the charge due to voltage fluctuations and electrical noise. Most of today's nickel-metal-hydride chargers use a combination of NDV, rate-of-temperature-increase (dT/dt), temperature sensing and timeout timers. The charger utilizes whatever comes first to terminate the fast-charge._

_Nickel-metal-hydride should be rapid charged rather than slow charged. Because of poor overcharge absorption, the trickle charge must be lower than that of nickel-cadmium and is usually around 0.05C. This explains why the original nickel-cadmium charger cannot be used nickel-metal-hydride. _

_It is difficult, if not impossible, to slow-charge a nickel-metal-hydride. At a C?rate of 0.1-0.3C, the voltage and temperature profiles fail to exhibit defined characteristics to measure the full charge state accurately and the charger must rely on a timer. Harmful overcharge can occur if a partially or fully charged battery is charged with a fixed timer. The same occurs if the battery has aged and can only hold 50 instead of 100% charge. Overcharge could occur even though the battery feels cool to the touch."_

The last paragraph on that BatteryUniversity.com quote also indicates that charge rates of 0.1-0.3C should be avoided - 
0.1C = C/10; 0.3C = C/3.3 close enough to C/3.......


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## SilverFox (Oct 6, 2007)

Hello Vincent,

The only "issue" I have with the Duracell document is there suggestion that a 0.1C charge for 12 hours will fully charge a cell. I believe there are some charge inefficiencies that they failed to factor in. The standard charge is for 16 hours at 0.1C. It may be possible to get a full charge with new cells in 14 hours, but as the cells age they need the full 16 hours.

Tom


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## Yenster (Oct 7, 2007)

UnknownVT, 
I think I understand a little better...it's not that these charge rates are bad for the battery...it's that it's difficult to detect charge state when these charge rates are used....which may then lead to overcharge, thus damage.

I make use to NiMh batteries for flashlights, remotes, and cameras. And the last time I thought about a better charger, I think LaCross brand, I thought it wasn't really worth it...but now I may take another look. Can you make a recommendation? I'm looking for something that sits on the counter, holds 4-8 batteries, AA and AAA, can leave batteries in the cradle for conituous maintenance, individual charging circuits, maybe some testing functions. I mainly use Rayovac Hybrids for its LSD feature, but I'm also looking for a NiMh battery that's higher capacity in my flashlights that get used often.

Appreciate the input. Thanks.


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## Delta (Oct 7, 2007)

Forgive me, for I am a noob when it comes to recharagables. I have a set of Energizer E2 2650 AA's that came with a small portable "travel charger" that the bottom slides out so the batteries can be inserted, and the plug folds down on the back. It has a single indicator light that goes off when fully charged.

**Is this OK for the eneloops (just bought a pack yesterday), and when that light goes out, does it mean "I'M DONE...UNPLUG ME NOW!" or is it more a "I'm finished charging, now I am trickle-charging to keep it topped off"???


ALSO:

**Are eneloops a good choice for say, a Fenix L2D flashlight? It gets maybe 15 minutes usage per day? I've been trying to find the best fit other than my E2 Lithiums, which it seems to run forever on, but are expensive.


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## Marduke (Oct 7, 2007)

Without further information, I would guess that the travel charger is a simple timed charger, and therefore not "good" for any NiMH battery.


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## UnknownVT (Oct 7, 2007)

SilverFox said:


> The only "issue" I have with the Duracell document is there suggestion that a 0.1C charge for 12 hours will fully charge a cell. I believe there are some charge inefficiencies that they failed to factor in. The standard charge is for 16 hours at 0.1C. It may be possible to get a full charge with new cells in 14 hours, but as the cells age they need the full 16 hours.


 
Thank you Tom/SilverFox - greatly appreciate that advice.

BatteryUniversity.com also agrees with that -
Charging nickel-based batteries 
(about 2/3 down the page)

"_*Slow Charger* - Also known as 'overnight charger', the slow charger applies a fixed charge of about 0.1C* (one-tenth of the rated capacity) for as long as the battery is connected. Charge time is 14-16 hours. Slow chargers are found in cord-less phones, portable CD players and other consumer goods_"



Yenster said:


> I think LaCross brand, I thought it wasn't really worth it...but now I may take another look. Can you make a recommendation?


 
Thanks for your kind words - but I am no expert - and still learning myself.

The LaCrosse BC-900 has had quite a few favorable comments - the fact that it can charge individual channels with individual display/monitoring - is great. Being able to choose the current again is a very good feature to be able to tailor the charge rate - the 200mA default rate might be a bit low - basically turning the default into a $50 slow charger....
- but it s very well featured.

My thoughts were similar to yours - $50 buys quite a few sets of eneloops or higher capacity NiMHs - about 5 sets of 4 that's a _LOT_ of batteries - so what if some get damaged - one would have to damage at least 16 batteries over say a $10 charger - just to break even.

I guess I was lucky as I got a cheapo jWin brand charger that came with 1800mAh batteries - detects end of charge by voltage drop -DV - and has a charge current of 900mA - so it falls (luckily) in a the quick charge "-DV detectable" range for my NiMH 1600-2500mAh for AA's and 800-1000mAh for AAA's. 

The charger had been used almost on a daily basis for over 21 months -rotating between the cheapo jWim 1800mAh that came with the charger, and 2 sets (of 4) 1600mAh RayOVac NiMH. The set of jWin 1800mAh eventually gave up the ghost (would no longer hold charge, so that was probably only approx 200 cycles). The 2 sets of RayOVac 1600mAh are still going strong - even today.

It has over-heated one set of 4x 1000mA AAA NiMh almost on the first charge - just once/twice(?) - but lucky for me I bought those from WalMart - so was able to return those cells. 

Other than those I have had one 2500mA NiMH AA go bad after about 3 months - but I'm not sure if it was the charger or simply just a bad cell. 

I now always make a note to check the charging at about the 1 hour mark for AAA's, and about 2 hours for AA - that's when I expect the charge to be finished - I feel the batteries for heat - if they feel hot, I stop the charge - but I haven't had hot batteries except for that one single set of 1000mAh Sakar NiMH AAA.

Not bad that I've had this charger since Sept/2003 - that's over 4 years - and it appears to work fine for my AA - 2100mAh Kodak Pre-Charged, 2500mAh Sakar/Digital Concepts NiMH ($6.25 from WalMart - now $7.95), 1600mAh RayOVac; AAA - 1000mAh Sakar/Digital Concepts ($4.95 from WalMart - now $5.95), and 800mAh eneloops.



Delta said:


> set of Energizer E2 2650 AA's that came with a small portable "travel charger" that the bottom slides out so the batteries can be inserted, and the plug folds down on the back. It has a single indicator light that goes off when fully charged.
> 
> **Is this OK for the eneloops (just bought a pack yesterday), and when that light goes out, does it mean "I'M DONE...UNPLUG ME NOW!" or is it more a "I'm finished charging, now I am trickle-charging to keep it topped off"???


 
I don't have the specs of that charger - but most cheap chargers are slow (or overnight) chargers of < C/10 - timer controlled at best if it has an indicator light. From everything I've read so far it does not appear to be possible to detect -DV (end of charge voltage drop) with charge rates of below about C/3 - C/2. 

So if the charger actually indicates end-of-charge - it is simply because of the timer - and not necessarily the state of the battery.



Delta said:


> **Are eneloops a good choice for say, a Fenix L2D flashlight? It gets maybe 15 minutes usage per day? I've been trying to find the best fit other than my E2 Lithiums, which it seems to run forever on, but are expensive.


 
They should work very well in the L2D - but runtime will not be as long as the e2 lithiums - or for that matter your Energizer 2650(?)mAh NiMH rechargeables -see -

Fenix L2D CE and L1D CE runtime graphs 

eneloops are rated at 1900(min) to 2000mAh - their capacity is about 75% of the 2650mAh NiMH - so the runtime is going to be corresponding shorter.

BUT if you do not use your flashlight frequently, and leave it for months - then eneloops or any of the LSD batteries make a lot more sense. The crossover point according to SilverFox is about 1 month (for eneloop/LSD vs 2700mAh NiMH)


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## Delta (Oct 7, 2007)

Thanks for the replies. I guess the next sensible question would be for someone knowledgable to point us in the direction of a recommended charger and retailer.


And, so what you are saying is, my E2 NiMHs that have been sitting in the wall charger for god-knows-how-long are probably toast now? Whoops.


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## UnknownVT (Oct 7, 2007)

Delta said:


> And, so what you are saying is, my E2 NiMHs that have been sitting in the wall charger for god-knows-how-long are probably toast now? Whoops.


 
No......

If they are still working and seem to last as long in your equipment/flashlight - then they are probably OK.

Slow or overnight chargers are not particularly efficient or effective for NiMH - there are better chargers - 
but their advantage is that they probably take a long time to overcharge (damage) the batteries - if the charge is timer controlled - then this is fairly unlikely - 
unless one persists in "top-up" charge on batteries that are near full charge 
(ie: the timer charger will just charge for the 12-16 hours despite batteries were nearly full to begin with - leading to over-charge, and possibly over-heating - not good).

I have not heard of Energizer e2 rechargeable NiMH - especially 2650mAh(? - that capacity sound like Duracell) 
- would you mind please looking at the batteries and let us know what it says on the label?

Better yet please look at the label of the charger - 
brand, model #, and any ratings?

If they are Energizer - then please look at -

http://data.energizer.com/

under the Product Group drop-down box - select 
"Chargers Rechargeable" - 
(battery data sheets - choose "NiMH Rechargeable".)


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## Delta (Oct 7, 2007)

My bad...they're the 2500's.


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## UnknownVT (Oct 7, 2007)

Delta said:


> My bad...they're the 2500's.


 
OK... if it is Energizer - 
could the charger be the CHDC ?






Specs -





This is as it says timer based 
timed for 8.5 hours at a rate of 360mA for AA's - 
that's a charge of 360 x 8.5 mAh = 3060 mAh.

For eneloops at 2000mAh that's a 153% capacity charge - which may be just a little high - 
probably better off stopping the charge at about 6.7 to 7 hours.

The problem of a charge current of 360mA is that it's just a bit too high for over-running on time which then may be more prone to over-charging/heating.

BUT it seems to have worked fine for you on the 2500mAh Energizer NiMH.


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## Turbo DV8 (Oct 7, 2007)

So, bottom line is that, despite the dire warnings against 0.1 - 0.3/0.5 C charging, if in fact cells are terminating at 0.1 C without hovering at maximum voltage too long and/or becoming excessively hot, then it is OK? I ask, because don't the higher temperatures attained when charging at higher rates shorten cell life? Also, doesn't a slower charge aid in better and more complete charge absorbtion?


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## Delta (Oct 7, 2007)

Yeah, thats the one I have.

Maybe I'll just buy the 2 Eneloops with the charger for $12.00 so I just have the right one.


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## UnknownVT (Oct 7, 2007)

Turbo DV8 said:


> So, bottom line is that, despite the dire warnings against 0.1 - 0.3/0.5 C charging, if in fact cells are terminating at 0.1 C without hovering at maximum voltage too long and/or becoming excessively hot, then it is OK? I ask, because don't the higher temperatures attained when charging at higher rates shorten cell life? Also, doesn't a slower charge aid in better and more complete charge absorbtion?


 
yeah, people have been charging NiMH with slow'ish chargers for years without too many problems - 
so much so that a _LOT_ of people say slow is better than fast charging (despite authorative information that says fast charging of NiMH is better - see BatteryUniversity.com)

Slower timered charging is generally OK - just slow, and not optimum. 

It is worthwhile checking by feel to see if the batteries are getting "hot" (unfortunately that's a loose definition - but it's better to stop charging and have an under-charged battery than to cook it)

The real problem probably is doing "Top-Up" type charging with timered chargers - this leads to possible over-charging/heating - if the batteries already had pretty good charge already.


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## SilverFox (Oct 7, 2007)

Hello Turbo DV8,

The bottom line is that it depends on your charger...

If your charger utilizes negative delta voltage or a change in temperature with respect to time, you will get better life from your cells by charging at a rate that insures a strong end of charge signal. This rate is the 0.5 - 1.0C rate that is recommended by the battery manufacturers.

A slow charge can give you a more complete charge IF it is properly terminated. If not, you end up with an overcharge situation which promotes large crystal growth and separator dry out. The question of cell temperature comes into this discussion. If the cell does not heat up excessively, does that mean that there is no damage? I think the answer can be found from those who insist on leaving cells in the charger to make sure they are fully charged and ready to go. You will find that these cells often are ruined by this process. In this case the evidence seems to point to the fact that cells can be ruined by overcharging even if there is no corresponding over heating.

Tom


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## UnknownVT (Oct 7, 2007)

Delta said:


> Maybe I'll just buy the 2 Eneloops with the charger for $12.00 so I just have the right one.


 
That's a great price -

eneloop USA product page 

pdf manual for eneloop compact charger


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## UnknownVT (Oct 7, 2007)

SilverFox said:


> A slow charge can give you a more complete charge IF it is properly terminated. If not, you end up with an overcharge situation which promotes large crystal growth and separator dry out. The question of cell temperature comes into this discussion. If the cell does not heat up excessively, does that mean that there is no damage? I think the answer can be found from those who insist on leaving cells in the charger to make sure they are fully charged and ready to go. You will find that these cells often are ruined by this process. In this case the evidence seems to point to the fact that cells can be ruined by overcharging even if there is no corresponding over heating.


 
As always I bow to Tom/SilverFox's expertise.

Leaving batteries in the charger - even slow chargers - is probably not a good idea, as this opens the possiblity of over-charging - possibly without any over-heating indication.

So in the range 0.1-0.3C charge rates where the -DV delta voltage drop is hard to detect - it would be hard to determine the end of charge - this can lead to over-charging - with or without over-heating.

Thanks Tom.


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## onthebeam (Oct 7, 2007)

PlayboyJoeShmoe said:


> My Energizer 15 minute charger never touches my LSD batteries!!!!



One of our preeminent battery gurus here, Silverfox, does use the 15 minute charger from time to time with his Eneloops and hasn't noticed any ill effects, if I am remembering his earlier posts correctly.

A case of all good things in moderation? I like an occasional big bowl of Haagen Daz from time to time, but wouldn't eat it morning, noon and night daily.


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## Turbo DV8 (Oct 7, 2007)

SilverFox said:


> If your charger utilizes negative delta voltage or a change in temperature with respect to time, you will get better life from your cells by charging at a rate that insures a strong end of charge signal. _*This rate is the 0.5 - 1.0C rate that is recommended by the battery manufacturers*_.


 

Would one of those be Sanyo? Devil's Advocate, here. So, a Sanyo Eneloop AA cell should be charged at 1A - 2A? If so, why does Sanyo package their Eneloop NiMH AA batteries with their "smart" independent channel charger which charges at about 300 mA, or 0.15C? Even the two-bay Sanyo charger charges only at 0.25C.


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## SilverFox (Oct 7, 2007)

Hello Turbo DV8,

Yes, Sanyo recommends 1C charging of Eneloop cells.

I have emailed them asking why they don't provide a 1 - 2 hour charger with their Eneloop cells. They did not respond.

Perhaps you may want to email them and see if you get better results.

Another thought comes to mind... Perhaps their chargers do not utilize negative delta voltage or change in temperature as their primary termination methods...

Tom


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## TPA (Oct 7, 2007)

Yenster said:


> . Can you make a recommendation? I'm looking for something that sits on the counter, holds 4-8 batteries, AA and AAA, can leave batteries in the cradle for conituous maintenance, individual charging circuits, maybe some testing functions.



Quite a few options in that category. There's the LaCrosse 900/700 chargers, handles 4 cells at a time and they seem to have remedied the fire hazard issues. Another charger/analyzer is the Maha C9000. Similar features, has a few differences in how it operates, doesn't have any limitations on simultaneous charging like the LaCrosse and there's quite a bit of info on the forum about it. If you don't need the testing functions, the Maha 800S charger has 8 individual channels and is happy to do AA & AAAs simultaneously. It also has a charge-discharge-wait-charge cycle to recondition batteries. Personally, I have the Maha C9000 & 800S. I primarily use the C9000 for analyzing/testing/deep reconditioning of spent NiMH (regular) batteries, while the 800S handles the charging. The C9000 can charge at high(fast) rates, BUT, reconditioning & breaking in batteries takes a LONG time (33 hrs), so the 800S is the real workhorse for me. If I could only have one charger, it'd be the 800S. I have too many battery-operated devices to consider having the C9000 as my only charger. I'm sure there's other places to buy them, but I bought mine from Thomas Distributing (http://www.thomas-distributing.com). Been very pleased with these chargers and eneloops so far. I'm slowly replacing all of my Energizer AA & AAA NiMH batteries which seem to have lost most of their capacity, probably due to the 15 minute Energizer charger I used to charge them with.


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## TPA (Oct 7, 2007)

Turbo DV8 said:


> Would one of those be Sanyo? Devil's Advocate, here. So, a Sanyo Eneloop AA cell should be charged at 1A - 2A? If so, why does Sanyo package their Eneloop NiMH AA batteries with their "smart" independent channel charger which charges at about 300 mA, or 0.15C? Even the two-bay Sanyo charger charges only at 0.25C.



My guess would be cost. Good quality power supplies aren't cheap. It also appears that they bought an off-the-shelf charger and had it repackaged as their own. When you think about the retail world, are people willing to spend $30-80 for a quality AA/AAA charger? Probably not. At least not in the USA. 

Similarly, why does Energizer sell 15 minute chargers? Most here agree that they excessively (harmfully) heat batteries and don't fully charge the batteries. So why would Energizer possibly make and sell these? Consumer convenience & to sell more batteries are the only reasons I can think of.


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## SilverFox (Oct 8, 2007)

Hello TPA,

Now let's not get too harsh on the 15 minute chargers...

It is true that they are harder on cells than 1C charging, but I have never heard of one missing the end of charge termination. You are right that they don't fully charge cells in the 15 minutes, but if you are in a hurry, 96% is close enough.

The 15 minute chargers are the most sophisticated chargers around. They are even more sophisticated than most of the hobby chargers. If you only used the 15 minute chargers, you would never have to deal with crap cells. They reject questionable cells and don't bother fooling with them.

The advantage of the 15 minute chargers has been greatly reduced by the low self discharge cells, but there still is a place for them.

If nothing else, everyone should own one to determine if they have crap cells...  

Tom


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## Turbo DV8 (Oct 8, 2007)

15 minutes? So a 2700 mAh AA cell would be charged damn near 11 amps? Jesus, that's just insane. Hard to imagine how that would _not_ place an aweful hit on a cell. I wouldn't even expect a cell to _deliver_ 11 amps for 15 minutes. How could it possibly charge at 11 amps in that amount of time? I don't expect a detailed explanation. I'm just incredulous, here. 15 minutes.. holy moly...


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## UnknownVT (Oct 8, 2007)

Turbo DV8 said:


> 15 minutes? So a 2700 mAh AA cell would be charged damn near 11 amps?


 
The Energizer 15 min Charger is rated for 2200mAh NiMH - 
even so it is still rated at 7.5Amps.....

The specs from their pdf document (CH15MN) - 






I've noticed even 4x 2200mA is still more than 7.5A. 
So either the charge time is a bit longer - 
or maybe the 15min charger under-charges a bit? 
- note also the primary charge time of 20 mins (a timer cut-off?)


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## Bort (Oct 8, 2007)

Here's the specification for the Quick Charger I purchased at Fry's. It came with 2 AA Eneloops for $16.99
http://www.energy.sanyo.com.sg/chargerproduct.asp#
The model number of the one that I bought is NC-MDRO2.
The output listed on the back of the charger is:

Output:
DC1.2v
550mA x2(AA)
380mA x2(AAA)


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## UnknownVT (Oct 8, 2007)

Bort said:


> Here's the specification for the Quick Charger I purchased at Fry's. It came with 2 AA Eneloops for $16.99
> http://www.energy.sanyo.com.sg/chargerproduct.asp#
> The model number of the one that I bought is NC-MDRO2.
> The output listed on the back of the charger is:
> ...


 
550mA for AA eneloops (2000mAh) makes that a 0.275C (C/3.6) charger for the AA's 

Similarly the 4 position charger sold with 4x AA eneloops model - GES-MQN05-4 (and the CostCo special powerpack) (Download pdf Instruction Manual)






is spec'd for AA at 300mA - so that's a 300/2000C = 0.15C or about C/7 charger......

Both the chargers are below 0.3C - where the end of charge voltage drop (-DV) is almost non-existent according to the various authoritive documents. 

But from what I've read both these chargers appear to be "intelligent" - 

So how do they detect the end of charge if the -DV is not detectable?


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## PlayboyJoeShmoe (Oct 8, 2007)

You got me by the short hairs but the 4 place one is what I use along with the Duracell 4 place that shows increments of charge.

I have found NO problems so far using them and I use two NimH each day in my GPS and it runs 12 hours easily.


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## GarageBoy (Oct 8, 2007)

How do they handle 4+ amp loads?


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## UnknownVT (Oct 9, 2007)

PlayboyJoeShmoe said:


> You got me by the short hairs but the 4 place one is what I use along with the Duracell 4 place that shows increments of charge.
> I have found NO problems so far using them and I use two NimH each day in my GPS and it runs 12 hours easily.


 
The Duracell Power Gauge is rated at 400mA charge current that makes it 400/2000C for the AA eneloops = 0.2C or C/5 .

Again I have read very favorable reviews of this charger, and the posts here again seem to indicate that it is somewhat "smart" with the ability to terminate charge automatically - and not just by a simple timer.

So again I am not questing that the chargers work - but asking _*how*_ they work - 
since according to the documentation I've read between 0.1C-0.3C it is very difficult to detect the end of charge voltage drop (-DV) reliably - 
so what is being detected to terminate the charge when the batteries reach capacity?


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## redfish (Oct 9, 2007)

Short answer: 0 delta V.

Long answer:
NiMH's have a very small voltage drop per cell. Usually they are terminated when the voltage drops by about 10mV over a few minutes. Now, when being charged at a slow rate, below 1/3C, the voltage wouldn't drop, it will just plateau. I think Duracell literature is being way too cautious about not recommending 0 delta V termination. With 0 delta V, there may be false termination early in the charge cycle, but that can be mitigated by ignoring the voltage for a few minutes after charge start, and/or have a minimum voltage before the 0 deltaV termination kicks in (say above 1.3 V). Having a longer voltage sampling interval would also help.

I built a smart charger from Maxim712/713 ICs years ago, and they terminated just fine. You can find spec sheets of them here. It might give you some idea how chip designers would build a smart charger.

EDIT: If you call Maxim, they will send you some free(!) samples of their chips. Great for hobbiests!


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## NiOOH (Oct 9, 2007)

UnknownVT said:


> The Duracell Power Gauge is rated at 400mA charge current that makes it 400/2000C for the AA eneloops = 0.2C or C/5 .
> 
> Again I have read very favorable reviews of this charger, and the posts here again seem to indicate that it is somewhat "smart" with the ability to terminate charge automatically - and not just by a simple timer.
> 
> ...


 
It is indeed very difficult or impossible to detect -dV signal at these rates, there is none. Several chargers I know of, use max V (maximum voltage) to detect full charge and terminate. One such charger is Kodak K200. It charges, if I remember correctly at 300 mA for AA cells, and terminates when the cell voltage reaches approx 1.45 V/cell. I used to have it long time ago. It worked, but undercharged the cells by approx. 15%. The problem with maxV at low rates is hat different cells respond differently to charge currents. Cells with higher IR reach full charge at higher cell voltage compared to lower IR ones. Usually, designers set the maxV too low to ensure that any cell will terminate, which leads to undercharge.


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## Wassernaut (Oct 9, 2007)

I never thought that my asking a simple question would kick off such an interesting thread, and so much good info (for us noobs, especially). Thanks to all who have contributed, and especially to SilverFox for his in-depth knowledge. The father of the GOTHAM, my dream light, always comes through. - Larry


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## TorchBoy (Oct 9, 2007)

redfish said:


> EDIT: If you call Maxim, they will send you some free(!) samples of their chips. Great for hobbiests!


I tried that a while back but what they sent was SMD and I practically needed a microscope to see the pinouts. No chance for this hobbiest to solder that fine.


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## redfish (Oct 9, 2007)

TorchBoy said:


> I tried that a while back but what they sent was SMD and I practically needed a microscope to see the pinouts. No chance for this hobbiest to solder that fine.



You can specify the packaging format when you call. Surface mounts are not for hobbiests!


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## PlayboyJoeShmoe (Oct 9, 2007)

Thunk about it some more...

Why Eneloops?? 



















Why not???


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## PlayboyJoeShmoe (Oct 9, 2007)

dang double post... stupid 'puter


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## TorchBoy (Oct 9, 2007)

PlayboyJoeShmoe said:


> Why not???


'Cos they're more expensive than [molded mud] from [some Eastern country other than Japan].


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## Marduke (Oct 9, 2007)

TorchBoy said:


> 'Cos they're more expensive than [molded mud] from [some Eastern country other than Japan].




With a little searching, many places sell Eneloops for around $10 per 4 or less. There are also a number of other brands coming up with LSD technology at the same or less price than many regular NiMH. Rayovac Hybrids and Kodak pre-charged can be routinely be found where I live for less than 4/$10 is many B&M stores. I even found a source for regular NiMH and Rayovac Hybrids for 5/$1.00. I am now almost entirely LSD since I picked up my 44 hybrids at $0.20 each.


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## rroossinck (Oct 9, 2007)

Anyone using these batteries with insulin pumps? I've got a case of 'em from Costco and I want her to start using them, but she swears up and down that MedTronic, the manufacturer of her pump, says very specifically that you're not supposed to use anything other than good old alkalines. 

Help me prove her wrong.


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## TPA (Oct 10, 2007)

rroossinck said:


> Anyone using these batteries with insulin pumps? I've got a case of 'em from Costco and I want her to start using them, but she swears up and down that MedTronic, the manufacturer of her pump, says very specifically that you're not supposed to use anything other than good old alkalines.
> 
> Help me prove her wrong.



Hmm... the only Medtronic stuff (pumps & stimulators) I've played with are fully implanted and I don't recall what type of battery they use. In this case, have her try them and carry a set of alkalines with her if she has any concerns.


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## NiOOH (Oct 10, 2007)

TorchBoy said:


> 'Cos they're more expensive than [molded mud] from [some Eastern country other than Japan].


 
Surely, it's up to everyone to decide what's acceptable and what's not when it comes to prices, but IMO it is not worth compromising the performance or even the functionality of expensive equipment in order to save a small sum on cells. We buy cells just to power things that usually cost many times the cost of the cells. Also, many of us charge their cells on fairly expensive chargers.

It is chepaer to buy a cell that costs 3 Euro and would last for 200 cycles that to pay 1.50 Euro per cell for something that would die after 50-cycles, with possible venting and leakage into a 70 Euro charger


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## Buck (Oct 10, 2007)

TPA said:


> Quite a few options in that category. There's the LaCrosse 900/700 chargers, handles 4 cells at a time and they seem to have remedied the fire hazard issues.



FIRE HAZARD?!? I've had a BC-900 running frequently in our bedroom for a year or so. Do I need to relegate that unit to a distant room to avoid endangering my family?



> I'm slowly replacing all of my Energizer AA & AAA NiMH batteries which seem to have lost most of their capacity, probably due to the 15 minute Energizer charger I used to charge them with.



That might not be the only reason. I recall reading a thread that mentioned the Energizer 2500s were not holding up very well. (Sorry, don't have a thread number.) I have a bunch of those that my SO uses in a little LCD TV which she watches in bed almost every night. The cells heat up quite a bit, although the run time suggests that they are not exceeding 1C. Since it gets left on fairly often, the cells are sometimes run down to around 0.9 V in series, which admittedly is probably abusive. Quite a few of these cells are crapping out after roughly 200 cycles. Recharging is on a Maha 204W or the LaCrosse, so the charger shouldn't be at fault in my case.


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## TPA (Oct 10, 2007)

Buck said:


> FIRE HAZARD?!? I've had a BC-900 running frequently in our bedroom for a year or so. Do I need to relegate that unit to a distant room to avoid endangering my family?



It affected older units. Supposedly it's been fixed in V.33 and higher units. I don't have this particular charger, but I believe it shows the version # upon applying power. 



> That might not be the only reason. I recall reading a thread that mentioned the Energizer 2500s were not holding up very well. <snip> Quite a few of these cells are crapping out after roughly 200 cycles. Recharging is on a Maha 204W or the LaCrosse, so the charger shouldn't be at fault in my case.



I'm not even getting close to 200 cycles. More like 10-30 before the fast self-discharge & reduced capacity set in. I'm only getting 1100mAh max capacity out of some of these batteries. Thank God for the Sanyo eneloops. I'm in the process of replacing all of my Energizers with eneloops. Despite the lesser rated capacity, they're outperforming the Energizers in every single way. I've even started to replace alkaline batteries in remote controls & clocks with eneloops as they need replacement.


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## tino_ale (Oct 10, 2007)

Hum... interresting thread :thumbsup:

Talking about over-heat killing Ni-MH, does 40°C (104°F) sound good while charging Eneloops? What kind of temperature is "bad" for Ni-MH? 50°C is already too high? 60°C?


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## NiOOH (Oct 10, 2007)

Search the forum, this question has been discussed many times. In a word: 40 is OK, 50 is worse but not deadly, 60 is not OK if you are after extended cycle life


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## SilverFox (Oct 10, 2007)

Hello Tino ale,

A general rule of charging NiMh is that "healthy" cells are nearly fully charged when their temperature rises about 10C above ambient. As cells age, things change and they can get a little hotter. "Crap" cells can be unpredictable.

Tom


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## Burgess (Oct 10, 2007)

Lotsa' good info in this thread !


Thank you to everyone for sharing it with us.


:wave:

_


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## TorchBoy (Oct 10, 2007)

NiOOH said:


> Surely, it's up to everyone to decide what's acceptable and what's not when it comes to prices, but IMO it is not worth compromising the performance or even the functionality of expensive equipment in order to save a small sum on cells. We buy cells just to power things that usually cost many times the cost of the cells. Also, many of us charge their cells on fairly expensive chargers.
> 
> It is chepaer to buy a cell that costs 3 Euro and would last for 200 cycles that to pay 1.50 Euro per cell for something that would die after 50-cycles, with possible venting and leakage into a 70 Euro charger


I don't think I could have put it better myself. The last time I was tempted to buy some inexpensive NiMH AAs I worked out that at the current I would be using them at they would last about half the amount of time for each charge. Even if they're twice the cost, for twice the duration with each charge and hopefully at least twice the number of cycles, I'll actually use the Eneloops for four times the number of minutes/hours.

For that and to avoid disappointment I just won't buy cheap cells any more.


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## Mitch470 (Oct 10, 2007)

Windscale said:


> 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.


 
I use an Ansmann Energy 8 Charger and have used it for 3 years. Can I still use that on the Eneloop LSD batteries?


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## NiOOH (Oct 11, 2007)

SilverFox said:


> Hello Tino ale,
> 
> A general rule of charging NiMh is that "healthy" cells are nearly fully charged when their temperature rises about 10C above ambient. As cells age, things change and they can get a little hotter. "Crap" cells can be unpredictable.
> 
> Tom


 
Hi Tom.
I'm not sure that "10C above ambient" can be used as a rule of thumb. At room temperature (around 20C) this would mean that a fully charged cell would reach 30C. Temperature rise above ambient is dependent on charging current. This applies to the case of externally connected cell. If you add to this the heat contributed by the charger, in nearly all cases, when charging above 0.1C, the cell temperature will be quite a bit above 10C above ambient when _fully_ charged.

To me the rule should read: "Temperatures above 50C should be avoided during charging. Under no circumstances should the cell temperature rise above the maximum temperature specified by the manufacturer"


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## SilverFox (Oct 11, 2007)

Hello NiOOH,

The 10C above ambient generality actually came from NiCd charging days. A lot of the NiCd chargers were simple timer chargers and it was brought forth as a method to determine if your cells were charged.

As you have pointed out, it does not directly translate to NiMh charging, and there are some variables, but it still stands as a general rule.

Tom


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## NiOOH (Oct 12, 2007)

SilverFox said:


> Hello NiOOH,
> 
> The 10C above ambient generality actually came from NiCd charging days. A lot of the NiCd chargers were simple timer chargers and it was brought forth as a method to determine if your cells were charged.
> 
> ...


 
Hi Tom. 
I am afraid I have to disagree with you on this one. Thermodynamics of charging NiCd and NiMH are _totally_ dif_erent._
NiCd charging reactions are ENDOTHERMIC, which means that they consume heat. Only overcharging reactions are EXOTHERMIC, i.e. generate heat. That is why, cell temperatures are usually low and constant unil nearly the end of charge.
In contrast, both charging and overcharging reactions of NiMH are exothermic. This means that a NiMH cell starts to generate heat as soon as it is connected to a current source. Overcharging reactions of NiMH cells are strongly exothermic as well. That is why at a given charging current (expressed as a part of the cell capacity) NiMH cells run warmer, AT ANY TIME DURING CHARGE compared to NiCd cells. This is also why the rule of 10C over ambient cannot be applied to charging NiMH cells.


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## SilverFox (Oct 12, 2007)

Hello NiOOH,

I agree that the reactions are different, however at the end of the charge both chemistries heat up.

Perhaps the difficulty has to do with the term "general." Let me define it this way:

In general, if you have cells charging and some of them are 10C above ambient and the others are at ambient, and you pull the cells from the charger for use. Then the cells that are 10C above ambient will be at a higher state of charge than the ones that were pulled while they were still at ambient temperature.

Tom


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## NiOOH (Oct 12, 2007)

SilverFox said:


> Hello NiOOH,
> 
> I agree that the reactions are different, however at the end of the charge both chemistries heat up.
> 
> ...


 
Tom.
I guess we are getting into some nitpicking here... well let's go on then. In your example above, if one of the cells is of NiCd chemitry (the cell at ambient temperature) and the other is of NiMH chemistry (the cell at 10C above ambient) which one is more charged? Let's say both cells are charging at 1C. I cannot answer this, can you?
Besides, this was not the question. There was a question what cell temperature is OK and what is not, discussing NiMh cells (something that we have discussed many times here), to which you replied that it should be 10C above ambient. My opinion is that, this is NOT CORRECT for NiMH cells. At least you should know that it is dependent on the charging current. At 0.1C with a charger that allows enough space between cells, and between cells and electronics it may never be reached. At 1C, 10 degrees above ambient, even for externally connected cell may be reached at 50% state of charge.
It is my understanding that when we give advice here it should be based on solid knowledge.


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## blackwaterstout (Oct 12, 2007)

UnknownVT said:


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


 
So of these 4 brands which is number one? I know for a fact I've seen Rayovac Hybrids at my local stores but I've never seen the other three brands. Are those 4 brands practically equal? 

What are the maximum capacities for these new LSD batteries? 2500mah?

I'm going to pick up some for my new C-8 thats coming from DE and I'd like to get the best ones available. 

I have 3 chargers available. My oldest is an Energizer charger that is slow (15 hours), my second charger is a Rayovac that can peak detect and charge cells in 1 hour. My third and best charger is a Hobbico Accucycle Elite ($130) that can charge, cycle, and peak detect at any settible rate I choose.


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## UnknownVT (Oct 12, 2007)

blackwaterstout said:


> So of these 4 brands which is number one?


 
Eneloops are the most well known, and therefore probably the most poular.

The others all have had good reports - 
but we are in early days for LSDs - 
and there's probably bound to be some early enthusiasm.

From what I've read eneloops appear to hold their charge slightly longer, but with slightly lower capacity

eneloops are spec'd at 1900mAh minimum and 2000mAh typical,
the other 3 appear to be 2000mAh minimum and <=2100mAh - ie: slightly higher rated capacity.

Both eneloops and the Kodak Pre-Charged claim 1,000 cycles - 
whereas the other 2 claim only 500 cycles.

But at this stage probably any of them would be fine - 
however if you want to be safe - stick with Sanyo eneloops 
since Sanyo has had a very good reputation for their NiMH rechargeable batteries.

I use Kodak Pre-Charged because they were cheaper, easily available at WalMart, and seem to have good reports of capacity.

Kodak Pre-Charged at WalMart


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## SilverFox (Oct 12, 2007)

Hello NiOOH,



NiOOH said:


> I guess we are getting into some nitpicking here... well let's go on then. In your example above, if one of the cells is of NiCd chemitry (the cell at ambient temperature) and the other is of NiMH chemistry (the cell at 10C above ambient) which one is more charged? Let's say both cells are charging at 1C. I cannot answer this, can you?



The answer to your question is quite simple...

In general, (  ) the cell that is 10C above ambient will be at a higher state of charge.

Tom


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## SilverFox (Oct 12, 2007)

Hello Blackwaterstout,

The LSD cells have only been available for a little over a year now. It is still to early to determine which brand is the best. They all seem to be very good.

Tom


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## PlayboyJoeShmoe (Oct 13, 2007)

Probably through my own fault in charging, but also related to HIGH ambient temperature, I had two pair of Hybrids fail to run my GPS.

Since then I've had no problems and even those two pair function well.

I have 28 LSD (Eneloop, Hybrid and Kodak) that I rotate in my GPS. I don't charge nearly as often as I did with regular NimH, and use 4-7 hour chargers to recharge them.

I think they are at least 100% better than Energizer 2500.

I still have a bunch of Rayovac 1800, and in my pile of junk cells there are none of those. There are only a couple of E 2100 in that pile but as a general rule it is the high capacity cells that have failed me (E2500 and D2500)

I LOVE LSD NimH!!!


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## NiOOH (Oct 14, 2007)

SilverFox said:


> Hello NiOOH,
> 
> 
> 
> ...


 
WRONG!
I don't see anything "general" in a statement that is true only for a given chemistry, charging current, state of health of the cell in question, initial state of charge, and hardware heat management. There are simply too many "ifs" to make it general. 
The original question was:
*"Talking about over-heat killing Ni-MH, does 40°C (104°F) sound good while charging Eneloops? What kind of temperature is "bad" for Ni-MH? 50°C is already too high? 60°C?"*

This time, your answer to this question was missleading.
I suggest we stop poluting this thread. If you want to continue the discussion let us open a new thread.


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## blackwaterstout (Oct 14, 2007)

Stopped in Wally World yesterday and they had both the Rayovac Hybrids and the Kodak Pre-charged. The AA 4-pack cost $8.97 for the Hybrids and $7.88 for the Kodaks.

Does anyone know of any brick and mortar stores that carry Eneloops? I stopped in Sams Club yesterday and they didn't carry a single precharged battery. What about Target? Best Buy? KMart? Anywhere?

If I can't find the Eneloops anywhere local then I'll probably just buy the Kodaks sine they are a buck cheaper than the hybrids.

BTW, I have no clue if this has already been posted buy I did see on the eneloopusa site that there was a rebate for some free eneloop spacers that turn AA batts into C and D cell batts via a MIR. http://www.eneloopusa.com/pdf/eneloop_spacers_rebate_form.pdf


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## NiOOH (Oct 14, 2007)

blackwaterstout said:


> Stopped in Wally World yesterday and they had both the Rayovac Hybrids and the Kodak Pre-charged. The AA 4-pack cost $8.97 for the Hybrids and $7.88 for the Kodaks.
> 
> Does anyone know of any brick and mortar stores that carry Eneloops? I stopped in Sams Club yesterday and they didn't carry a single precharged battery. What about Target? Best Buy? KMart? Anywhere?
> 
> If I can't find the Eneloops anywhere local then I'll probably just buy the Kodaks sine they are a buck cheaper than the hybrids.


 
Check the Kodaks. If they are made in Japan they are most probably rebranded Eneloops. At least up to now, Kodak has ways used Sanyo-made cells.


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## JB (Oct 14, 2007)

SilverFox said:


> Hello Turbo DV8,
> 
> Yes, Sanyo recommends 1C charging of Eneloop cells.
> 
> ...


 
I have a Konnoc A099 charger. Specs as follows:

[FONT=Arial, Helvetica, sans-serif]Feature[/FONT]
+ Individual charging slots can charge 1-4pcs AA/AAA size Ni-MH/Ni-Cd rechargeable batteries. 
+ Widely used in families, business centers and offices. Can be charged by common power source, Available accessories: car kit and USB connector.
+ Advanced IC controls the charging process and auto power cut-off function with -△V control assures the batteries to be fully charged against over charged.
+ Intelligent LCD displays the whole charging process and the status of the battery capacity.
+ Refresh functions. It can eliminate the "memory effect".
+ Over-current protection. The constant current charging mode avoids the influence of current fluctuation to battery's performance, safety guaranteed.
+ Over-heat protection. The charger will automatically stop working if the temperature of the charger or batteries are too high.
+ The timer controls the maximum charging time strictly.
+ Detection of non-rechargeable batteries, short-circuited batteries or defective batteries, which the charger will not charge.
+ Automatic alarm function. The indicators flash in red and green alternatively if there's any problem.
+ Recommend to use with KONNOC brand Ni-MH/Ni-Cd rechargeable battery for better performance.
+ Portable in size.


Specification +Input: 100V -240V AC, 50/60Hz, 10W, or 12-14V DC, 1.0A
+Output: 1000mA, 


Looks like this would be a good match for the Eneloops?


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## GaryF (Oct 14, 2007)

blackwaterstout said:


> Does anyone know of any brick and mortar stores that carry Eneloops?



Circuit City carries them.


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## NiOOH (Oct 14, 2007)

JB said:


> I have a Konnoc A099 charger. Specs as follows:
> 
> 
> Looks like this would be a good match for the Eneloops?


 
Yes, it could be. Can you run it with the lid open? What is the spacing between cells when seated inside? 
If its electronics is stable and sensitive enough to sense a voltage drop of 5-10 mV per cell it will work with no dangerous overcharging and will be OK.


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## geepondy (Oct 14, 2007)

Guys, I recall when these first came out (Eneloops followed shortly by Rayovac Hybrids), the initial impression was that the Eneloops held a charge longer then the Rayovacs. Is this now considered not necessarily so? I know the Rayovac Hybrids are more readily available.

Also for these batteries, do you think it would be ok to use them in my tried and true Rayovac one hour charger?


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## UnknownVT (Oct 14, 2007)

NiOOH said:


> Check the Kodaks. If they are made in Japan they are most probably rebranded Eneloops. At least up to now, Kodak has ways used Sanyo-made cells.


 
Kodak Pre-Charged are made in China -











The Kodak Pre-Charged spec'd capacity of <= 2100mAh and 2000mAh minimum, 
are different from eneloop's 2000mAh(typical) and 1900mAh minimum.

From my (admittedly limited) survey so far, I've not come across any AA LSD batteries that I even suspect of being re-badged eneloops.


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## PlayboyJoeShmoe (Oct 14, 2007)

For a while now I have used the charger that came with 4 Eneloop at Walmart and the Duracell model CH21 4 place with seperate segmented charge indicators.

I have pulled batteries immediately after the charger indicates done, and have left batteries in overnight.

At first I was worried about heat and such, but neither of these chargers seem to hurt the batteries.

I run a pair each day in my Garmin Etrex Legend GPS, and can find no difference in Kodak, Eneloop or Hybrids in that application.

For a time I ran my M*g85 on Hybrids and it seemed to work peachy.

I have exactly 7 2500 NimH that still hold a charge and 19 2500 that have less than 1V after only a few days after charge.

I have about 20 E2100 that still "work" and close to 20 Rayovac 1800 that are still viable.

But I use Kodak, Eneloop and Hybrid everyday and can see no reason whatsoever not to. Nor can I see any problem using the chargers I do.

YMMV.... but not too much I think!


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## blackwaterstout (Oct 14, 2007)

I stopped at Wally World and Target today. Did a quick comparision. I bought a 4 pack of the Kodak AA batteries at $7.88 from Wally World. But here is the kicker. At Wal Mart the AA 4-pack of Rayovacs cost $8.97 while the charger pack (That comes with an 8 hour charger, 2AA's and 2AAA's) cost $18.97. That same charger pack at target cost $9.99! The pack at Target is the same thing as the Wal Mart pack except it says "New Look" in the upper left hand corner of the pack. IT's the same 8 hour charger with 4 cells. Seems odd that Wal Mart sells the same thing at nearly twice the price of Target. 

There is also a sticker on the package that is good for a $5 MIR with the purchase of an additional packe of Hybrid batteries. I bought the $9.99 charger pack along with a second pack of hybrids so I can send in the rebate. Overall counting the rebate I got a hybrid charger, 6 AA cells and 2 AAA cells for $12.00 cheaper than Wal Mart sells them for.


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## SilverFox (Oct 14, 2007)

Hello NiOOH,

Tino_ale posed this question a few posts back



tino_ale said:


> Talking about over-heat killing Ni-MH, does 40°C (104°F) sound good while charging Eneloops? What kind of temperature is "bad" for Ni-MH? 50°C is already too high? 60°C?



You replied



NiOOH said:


> Search the forum, this question has been discussed many times. In a word: 40 is OK, 50 is worse but not deadly, 60 is not OK if you are after extended cycle life



Question was answered…

Moving on…

I noticed that Tion_ale lives in Italy. I am not aware of the climate conditions in Italy, so I presented a general rule for charging. If the temperatures in Italy are hot on the day that Tino_ale is charging his cells, he may observe higher temperatures from his cells. 

In general, cells heat up at the end of the charging process. In general, the cell temperature will end up around 10 C above ambient near the end of the charge, with healthy cells.

There seems to be some difficulty with your ability to interpret the difference between a general statement and a specific statement. Let me try this again.

A specific statement would go something like this:

“All Eneloop cells manufactured in 2007 that are charged after previously being discharged to 1.0 volts at a rate of 500 milliamps, will see an increase in temperature of 10 C over the ambient temperature, at an ambient temperature of 25 C, when charging at a rate of 2000 milliamps on a charger that operates with a maximum surface temperature of 25 C and there are no other heat sources nearby.”

Please note that this statement is made up and while quite specific, there are still some details missing, so it is not totally specific. However, I think it illustrates the point of a specific statement.

A general statement would go like this:

“In general, batteries heat up near the end of the charge and when they reach 10 C above ambient, they quite often are fully charged, or nearly fully charged.”

OK, now let’s look at some data that supports my statement, and answers your question concerning the state of charge of cells of differing chemistries.

National Semiconductor has an excellent paper on charging in general and on using the LM2576 chip for charging. A look at Figure 2 shows voltage verses temperature graphs of both NiCd and NiMh cells. You can also find similar graphs at the various battery manufacturer web sites and at Battery University.

As you pointed out, NiCd chemistry is endothermic, and there is little temperature rise until the cell nears the end of the charge cycle. NiMh chemistry is exothermic and there is a gradual increase in temperature throughout the charge, but there is a rapid increase in temperature at the end of the charge.

It is interesting that both the graphs and the paper suggest that there is roughly a 10 C increase in temperature over ambient at the end of the charge…

While these graphs are specifically referring to an ambient temperature of 25 C and a 1 hour charge rate, IN GENERAL, this behavior applies to the recommended charging rates of 1 – 2 hours for NiMh chemistry and 20 minute – 1 hour charging for NiCd chemistry.

Standard charging (0.1C charge rate for 16 hours) involves very little change in temperature with healthy cells, so this would be an area where the general rule would break down. NiMh cells will still heat up, but you would most likely see less than a 5 C temperature increase.

Now, let’s get back to your question…



NiOOH said:


> I guess we are getting into some nitpicking here... well let's go on then. In your example above, if one of the cells is of NiCd chemitry (the cell at ambient temperature) and the other is of NiMH chemistry (the cell at 10C above ambient) which one is more charged? Let's say both cells are charging at 1C. I cannot answer this, can you?



Looking carefully at Figure 2, I can not come up with a single instance where a NiCd cell at ambient temperature while charging is at a higher state of charge than a NiMh cell that is 10 C above ambient. And Figure 2 happens to specifically be at a 1C charging rate.

I stand by my original answer that the warmer cell is at a higher state of charge.

Is it possible for a general rule to be broken by a specific example? Of course, that is why it is a general rule and not a specific rule.

In general, cells approaching or at full charge will be around 10 C above ambient temperature. Also, I assume that people have recycled their “crap” cells and are using healthy, vibrant cells. Crap cells can be unpredictable and can violate some, or all of the general rules.

Tom


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## JB (Oct 14, 2007)

NiOOH said:


> Yes, it could be. Can you run it with the lid open? What is the spacing between cells when seated inside?
> If its electronics is stable and sensitive enough to sense a voltage drop of 5-10 mV per cell it will work with no dangerous overcharging and will be OK.


 
Yup, can run it with the lid open. The cells are spaced closely together. How can I tell if the charger will sense a voltage drop of 5-10mV per cell?


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## NiOOH (Oct 15, 2007)

JB said:


> Yup, can run it with the lid open. The cells are spaced closely together. How can I tell if the charger will sense a voltage drop of 5-10mV per cell?


 
While you can measure it, it is not necessary. Just touch your cells right after they have finished chaging. They should be warm but no hot to the touch. You should be able to hold them without any pain or burning sensation.


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## NiOOH (Oct 15, 2007)

Hello SilverFox.


_I also stand by my statement that 10C above ambient is a missleading advice_. 
Ever wondered why it is not used by charger manufacturers as a termination criterion? I've seen it listed as a possibility but never implemented.

You can find documents like the one by Duracell (often cited by you BTW), where on p11 Fig 6.1.2. there is a comparison between NiCD and NiMH chemistries in terms of charging temperature. 
I believe my library of documents on electrochemistry is at least no smaller than yours, perhaps several times bigger, so let us not start throwing links at each other. Besides, I've always said that manufacturers data should be taken with a grain of salt. GP for instance publishes temperature data that I find optimistic at best. Un fortunately, real publications are hard to get for free.
If you are ready to enter the amateur science field, I'd recommend to get a membership for the Journal of The Electrochemcal Society. They have an excellent section on batteries and energy storage, with plenty of interesting scientific articles and real-life data, published by professionals, most often with no connection to battery or charger manufacturers. 
Copyright laws does not permit sharing this content with you, but there are some really interesting articles there, especially if you have some basic knowledge of physics and chemistry.


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## Marduke (Oct 15, 2007)

:touche: 

Boys, boys, we get it.... overcharged cells get hot.

Moving on....


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## GaryF (Oct 15, 2007)

geepondy said:


> Guys, I recall when these first came out (Eneloops followed shortly by Rayovac Hybrids), the initial impression was that the Eneloops held a charge longer then the Rayovacs. Is this now considered not necessarily so? I know the Rayovac Hybrids are more readily available.



I think the initial impression was based upon manufacturer specs, but it has been also proven out by some of the end user tests. The reality is that the difference observed so far is not that significant for most applications - both batteries should still retain most of their charge after a year. 



geepondy said:


> Also for these batteries, do you think it would be ok to use them in my tried and true Rayovac one hour charger?



If it's a smart charger it should be ok, if it's a timed charger I would look for something else.


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## Marduke (Oct 15, 2007)

GaryF said:


> I think the initial impression was based upon manufacturer specs, but it has been also proven out by some of the end user tests. The reality is that the difference observed so far is not that significant for most applications - both batteries should still retain most of their charge after a year.



Agreed. Hybrids may not be quite as robust or quite as LSD, but having to top off a battery every 6 months instead of every 2-4 weeks is a good improvement for what is now a common battery is many B&M stores.


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## UnknownVT (Oct 15, 2007)

blackwaterstout said:


> But here is the kicker. At Wal Mart the AA 4-pack of Rayovacs cost $8.97 while the charger pack (That comes with an 8 hour charger, 2AA's and 2AAA's) cost $18.97. That same charger pack at target cost $9.99!


 
That's interesting - because at my 2 local WalMarts had the RoV Hybrid charger packs at $9.84 - just a few cents lower than the two local Targets ($9.99).

I bought one from WalMart a few weeks ago at that price 
- but took it back because I didn't like the slow timer charger.

Was the price just on the peg - or did you check price with their self-service scanner?


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## blackwaterstout (Oct 15, 2007)

UnknownVT said:


> That's interesting - because at my 2 local WalMarts had the RoV Hybrid charger packs at $9.84 - just a few cents lower than the two local Targets ($9.99).
> 
> I bought one from WalMart a few weeks ago at that price
> - but took it back because I didn't like the slow timer charger.
> ...


 
I didn't check the price on the self service scanner but I did check the SKU from the pack with the SKU on the peg. They matched. Oh well. Even at $9.99 you are getting 4 cells plus the charger so considering 4 cells cost $8.99 you are getting the charger for like $1.00 Thats not too bad.


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## UnknownVT (Oct 15, 2007)

blackwaterstout said:


> I didn't check the price on the self service scanner but I did check the SKU from the pack with the SKU on the peg. They matched.


 
That's a HUGE jump in price of the Hybrid charger pack at WalMart - and one would be paying over $10 for that cheapo/slow charger - 
like you said at under $10 (at Target and when I bought a set some weeks ago at WalMart) - it's a deal - since 4 batteries alone will set one back $9 - so the charger would only be $1.......


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## PlayboyJoeShmoe (Oct 16, 2007)

I haven't checked the 4 pack and charger thing at Walmart, but

Oh wait, I was thinking about something else! I was looking at the Duracell charger and thinking Hybrids (which it chargers just fine!)

A 1$ stupid charger might be better than no charger.... but I trust the Duracell and the Eneloop charger.


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## UnknownVT (Oct 16, 2007)

blackwaterstout said:


> But here is the kicker. At Wal Mart the AA 4-pack of Rayovacs cost $8.97 while the charger pack (That comes with an 8 hour charger, 2AA's and 2AAA's) cost $18.97. That same charger pack at target cost $9.99!


 
Just out of curiosity I stopped into one of my local WalMarts tonight - they still had the RoV charger pack with 2AA and 2AAA - the peg price was $9.74 - just to be sure I took it to one of their self scanners and it returned $9.57! (in this case the charger was equivalent to 60cents....)


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## blackwaterstout (Oct 16, 2007)

UnknownVT said:


> Just out of curiosity I stopped into one of my local WalMarts tonight - they still had the RoV charger pack with 2AA and 2AAA - the peg price was $9.74 - just to be sure I took it to one of their self scanners and it returned $9.57! (in this case the charger was equivalent to 60cents....)


 
You know how sometimes no matter how well you look at something you think you are reading it correctly and it turns out you've made a brain fart and misinterpretted it. Maybe this is one of those times. If I'm near that Wal Mart tonight I'll stop by and double check what I saw. Who knows, maybe I was hallucinating 

I'd really like some Eneloops but I don't have a Circuit City or Costco nearby. I did stop in Best Buy to see what type of hybrids they sold. In a word.........None........ I asked the sales guy if they sold any precharged rechargables and he was like "huh?"


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## GaryF (Oct 16, 2007)

I can vouch for what blackwater saw in Walmart, as I saw the same pricing when I was shopping ROV Hybrids about 6 months back... $19 something in Walmart for the same package that I had already purchased at Target for under $10. I also didn't verify the price, and as I said, it was awhile back, but that was what I saw on the rack.


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## PJbatman (Oct 16, 2007)

Yeah, my dad just bought the Rayovac Hybrid charger with (2) AA and (2) AAA for ~$9.99 @ Target, after I talked him into the low discharge technology being worth it!


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## Eugene (Oct 16, 2007)

geepondy said:


> Also for these batteries, do you think it would be ok to use them in my tried and true Rayovac one hour charger?



Is it the PS4?


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## PlayboyJoeShmoe (Oct 16, 2007)

At at least one Walmart I've been in (Livingston fer sure!) they sell (or did) a 4 pack of Eneloops with a charger that ain't too shabby.

Was in a Walmart today but with Dad and on a mission so I have no idea what they had as far as batteries or lights. Yeah, I know.


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## redfish (Oct 17, 2007)

UnknownVT said:


> From my (admittedly limited) survey so far, I've not come across any AA LSD batteries that I even suspect of being re-badged eneloops.



Sony Cycle Energys are eneloop rebrands. I suspect, but have no evidence of, Duracell pre-charged being eneloops.


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## UnknownVT (Oct 17, 2007)

GaryF said:


> I can vouch for what blackwater saw in Walmart, as I saw the same pricing when I was shopping ROV Hybrids about 6 months back... $19 something in Walmart for the same package that I had already purchased at Target for under $10. I also didn't verify the price, and as I said, it was awhile back, but that was what I saw on the rack.


 
I am not casting any doubts or aspersions about what you saw - it's just that seems a very high price - like you said yourself Target had the same thing for $9.99 and generally WalMart is slightly cheaper than Target - and not normally almost _TWICE_ the price.

FWIW - this is my receipt from WalMart dated 9/12 which shows the price I paid at my local WalMart for the RoV Hybrid charger set - $9.74 -


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## UnknownVT (Oct 17, 2007)

redfish said:


> Sony Cycle Energys are eneloop rebrands. I suspect, but have no evidence of, Duracell pre-charged being eneloops.


 
Thank you very much for that - 
I did a quick web search on Sony Cycle Energy and found this page - translated (original Japanese page).

Can't comment on the Duracell Pre-Charged - as there is so little information on them - even the Duracell Pre-Charged page.


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## Jackson (Oct 17, 2007)

> Does anyone know of any brick and mortar stores that carry Eneloops?


I picked up some Eneloops at HHGregg. They had 4 packs for $8, charger w/4 batteries for $18 and charger with 2 batteries for $13.


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## SilverFox (Oct 17, 2007)

Hello Vincent,

Interesting article...

Tom


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## Sarratt (Oct 17, 2007)

Eugene said:


> Is it the PS4?



I'm also waiting for one of the 'wise ones' to answer about the PS4 Rayovac One Hour charger being ok for eneloops.

I don't think it's a timed charger as each slot has it's own light indicator showing charging or not.

I've searched and can find very little documentation about this charger. 

( the very first PS4 's were almost defective and the newer models were renamed something like PS4b )


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## UnknownVT (Oct 17, 2007)

Sarratt said:


> I'm also waiting for one of the 'wise ones' to answer about the PS4 Rayovac One Hour charger being ok for eneloops.
> I don't think it's a timed charger as each slot has it's own light indicator showing charging or not.
> ( the very first PS4 's were almost defective and the newer models were renamed something like PS4b )


 
I'm not wise - but a google on RayOVac PS4 found -

Performance Measurements of Some NiMH Battery Chargers

and 2 more short reviews -

Rayovac 1-Hour NiMH/NiCd Charger

RAYOVAC 1 HOUR CHARGER

from what I skimmed - this looks fine for eneloops - charge current = 1.7A according to the first review - that's about 0.85C to 0.89C which is actually within the optimum range for charging NiMH of 0.5C to 1.0C.

Even charging temperature seems OK at 40degC.

One channel/battery at a time looks great!


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## blackwaterstout (Oct 17, 2007)

I was wakling by Ripoff Shack (Radio Shack) today and decided to take a look at their LSD batteries. To my horror they cost $19.99 for a 4-pack of AA's! I asked the salesman why their LSD's cost at least 100% more than Eneloops or Hybrids and his answer was that they are designed better 

FYI, They were rated at 2000mah on the package. Could they be Sanyo cells? Not that it matters....................


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## Burgess (Oct 17, 2007)

Radio Shack --


You've got questions,

We've got blank stares.


:nana:

_


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## Eugene (Oct 17, 2007)

Sarratt said:


> I'm also waiting for one of the 'wise ones' to answer about the PS4 Rayovac One Hour charger being ok for eneloops.
> 
> I don't think it's a timed charger as each slot has it's own light indicator showing charging or not.
> 
> ...




I have a PS4. I had quit using re-chargeable batteries for a couple years partly because of it. I bought some sanyo 1650mAh NiMH batteries to use in our digicam and after a couple years it would get to where the camera would shut off after less than a dozen pictures. When I started reading up on chargers I found a web site that tested several and the PS4 was listed as charging to 79% after one hour when it says charge complete. So part of my issue with those older batteries was they weren't getting fully charged. I still use those old ones and find that I can pull them hot off the PS4 and they run a baby monitor for about 2-3 days. Charging the same batteries on a MAHA C401FS the same baby monitor will run for 2-3 weeks.
So safe or not I can't say but it turns out to be a pretty poor charger. I'll happily sell mine to anyone interested, it even has the car charger.


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## PlayboyJoeShmoe (Oct 17, 2007)

I KNOW it's been asked and answered somewhere, but one more time please about the Energizer 15min. I haven't used mine in quite a while because it seems TORTURE on batteries. Not that I can prove it or anything...


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## Sarratt (Oct 17, 2007)

Vincent ..Thanks for the links and information. I had seen the first two links but thought they might have been a bit dated. Now if I can just find some reasonably priced eneloops here in Ottawa. 

Eugene .. I think that the early PS4 did have some problems. I haven't had the problems you have.


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## swxb12 (Oct 17, 2007)

> Why Eneloops??



Because I just realized that while my Energizer NiMHs work fine, I will not be able to charge them during a power outage and they will continue to self-discharge at an alarming rate - especially if they weren't just topped off at the time of the outage...

A stockpile of charged-up Eneloops (or Alkalines, for that matter) would prove to be a lifesaver.


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