Energizer 2500 NiMHs .. very strange

[Bonky]

Ok so the posts here made me wanna test out some of my girlfriend's Energizer 2500 mah NIMHs that I gave her 6-8 months ago.

All 8 of mine that I've had for 1.5 years hold a charge well and are at ~2400+ true mahs, according to my LaCrosse charger.

3 of her 4 were below 0.5v and all are currently refreshing in my charger since their capacities had dropped to ~200 mah. Terrible. :mecry:

Here's my question: the charger I had used for about a year with mine before getting the La Crosse, the Energizer CHFM1, has *no trickle charge*.. ever. It charges at 360 ma and, when it turns off, turns off completely.

see: http://data.energizer.com/PDFs/chfm1.pdf

Her charger, the Energizer CHDC7, charges at 450 ma and has a 50 ma trickle at the end. Sometimes she keeps her batteries on for hours and hours or even days.

see: http://data.energizer.com/PDFs/chdc7.pdf

I'm wondering if 1) Energizer NIMHs are crap and I just happened to get 8 good ones or 2) Energizer NIMHs are extremely sensitive to over charging.

Is 50 ma enough to ruin a NIMH if left on for, say, 2-3 days after charging? :thinking:

 

[mdocod]

The bigger mystery here is why your cells are still functioning. Most Energizer 2500s were total crap, and developed self-discharge rates so massive that they were practically unusable...

Theories:
1. You use your cells frequently enough not to notice the self-discharge, and have kept cycling them and keeping them in the ideal voltage range over the life of the cells. While your girlfriends cells were abused in various ways, the combination of over-charge via trickle charging, and the possibility that they may have sat around for days or weeks or months in a state of over-discharge may have all added up to a recipe for failure.

2. Your 2500s are from China, while hers are from Japan. (not this is not a joke)

Eric

 

[Bonky]

thanks for your reply. Actually, 4 of mine are the Chinese (black top) ones, and 4 are the Japanese (green top) ones. All 4 of hers are Chinese.

You're right that I tend to "baby" my batteries. Recharging them as soon as they deplete and so forth. However, some of them have sat around for months without use.

Admittedly her use was harder (digital camera/flash) -- while mine was not so much (xbox controllers, cordless mouse, etc).

I dunno, it's weird.

 

[rockz4532]

The bigger mystery here is why your cells are still functioning. Most Energizer 2500s were total crap, and developed self-discharge rates so massive that they were practically unusable...

Theories:
1. You use your cells frequently enough not to notice the self-discharge, and have kept cycling them and keeping them in the ideal voltage range over the life of the cells. While your girlfriends cells were abused in various ways, the combination of over-charge via trickle charging, and the possibility that they may have sat around for days or weeks or months in a state of over-discharge may have all added up to a recipe for failure.

2. Your 2500s are from China, while hers are from Japan. (not this is not a joke)

Eric

i have a ton of 2500 and 2300 green top energizers. as far as im concerned i havent used them for a year, just charged them yesterday, and they work perfectly, running my magled for 3 hours. they self discharge to about 50 percent brightness in 3 weeks, i dont think thats crap.

 

[Mr Happy]

they self discharge to about 50 percent brightness in 3 weeks, i dont think thats crap.

That's what we don't like about them. We are used to batteries that will still give hours of full brightness run time after 3 weeks...

 

[PhantomPhoton]

they self discharge to about 50 percent brightness in 3 weeks, i dont think thats crap.

imho that is very much crap, even excluding new LSD technology.
:ironic:
I have old (first gen retail afaik) Ray-o-vac NiMh AAs that outperform most of the Energizer 2500s that I bought. Sad but true unfortunately. I still have a couple of those old ray-o-vacs working reasonably well for their age today. I've recycled all of the energizers and I made that decision well before I ever stubled into CPF and heard how bad they've been for other users as well.

 

[EngrPaul]

Energizer 2500 mAh's last about as long as the Christmas toys they are put in.

Other cells lose their capacity gradually. Energizers just "crap out", as previously stated.

I recommend Sanyo (not fakes off ebay) and Powerex, they've always served me well.

 

[rockz4532]

oh! ive been living under a rock for a couple years! i thought three weeks was decent for rechargeables

 

[Yoda4561]

Eneloops are good for about a year or two sitting idle, less obviously if the device is drawing power (like a small clock, and some *defective imo* digital cameras.)

 

[Bonky]

Mine don't drop out after that long, IIRC. I'll have to run some tests, but IIRC when I toss them on the charger they're in the high 1.2s to low 1.3s even after a couple of months.

Have to run some tests.

 

[Marduke]

Half brightness after 3 weeks means they are DEAD. Half runtime would mean they are only half dead....


But even traditional NiMH looses at most about 30% capacity per month. Eneloops (or other LSD) is retains up to 85% over one YEAR.

 

[MrAl]

Hi,

My Energizer 2500's were hardly used at all and they self discharge to 0.00 percent
in about 3 days. I wrote to Energizer on the web and then called them, they
sent a coupon for more Energizer products (10 dollars) so i bought a set of
their AAA NiMH cells. The AAA's work ok but the 2500's were bad.

 

[Bonky]

what kinda chargers were you guys using for your 2500s?

 

[Lynx_Arc]

I have found the best use of the energizer 2500s are in their 15 minute charger for stuff you are using NOW.... or within a few hours of charging. After 1 day of charging the 2500s I have would not light my rayovac 1AA led headlam on high for more than 15 minutes when it should be closer to 3 hours but hot off the charger I get 2.5 hours or more which is better than the LSD cells get because they are close to 2500 instead of 2100mah. I don't know why there isn't a class action lawsuit against energizer for their 2500 nimh cells there should be.

 

[Lynx_Arc]

what kinda chargers were you guys using for your 2500s?

I have a BC900, rayovac 1hr charger and energizer 15 min charger. The batteries check out well in the BC900 as far as *capacity* is concerned but the self discharge is an abomination.

 

[RobSpook]

I was in the group of Energizer 2500 haters in the past also. I had 20 of the AA 2500 type and they all went sour, not holding a decent charge for over three weeks. I mailed all the batteries back to Energizer and they sent me a check for $50 to replace them (no coupons since at my APO location I may not have been able to use coupons.) I replaced them with 20 new Energizers and they have been working fairly well, but I make sure to only use them in my most used applications: My son's 7 LED lantern which he uses every night at bedtime (lasts about 3 weeks), and my younger sons crib music player (4 AA in C adapters) which plays for over an hour every night and lasts about 2 to 3 weeks. They have been continuously used for over a year, charging at 1300 on my c-9000. They are all at approx. 15 cycles, with a refresh/analyze done every 10th cycle.

I haven't done any long-term storage tests because I also own 60 Eneloops for this purpose

The Energizer AAA batteries have been continuously used for over three years and still take a full charge ~800mah. I am happy with the AAA's, but when these 20 AA batteries fail, they will be replaced with either more Eneloops or Imedions.

The value in my opinion has been good, because could you imagine the cost of C batteries to keep that music player running for two years?

 

[Yoda4561]

Just out of curiosity what charger were you using with the bad energizers? I've found my c9000 to be rather kind to the last two I have that aren't completely useless. Maybe the more conservative charge termination that it uses helps keep the 2500's last longer?

 

[Bonky]

is there anyone that charged their 2500s on a charger that had NO trickle charge? I'm going to do a shelf-life test on mine.. they've never been "trickled" and I've never seen them drop capacity in any abnormal way.

My hypothesis is that the batteries are simply easily screwed up by trickle charging.

 

[Marduke]

My hypothesis is that the batteries are simply easily screwed up by trickle charging.

Or any over charge, or over discharge, or a high rate charge, or a high rate discharge, or if you use them, or if you even look at them.


Seriously, if you stare these puppies down, you can actually watch them self discharge before you very eyes.

 

[Bonky]

well that's what I gonna be testing with mine. I let mine rest on small velvet pillows and watch them lovingly while they charge and fan them with a small hand fan while singing them little songs. Doesn't everybody?