As many here know when I am cut I leak battery acid. Some also are aware of my Transmitter Battery Pack Thread where I posted test results and some of the problems I have experience with these cells.

http://www.rcgroups.com/forums/showthread.php?t=327288

Also happen to have many post in this Thread.

http://www.rcgroups.com/forums/showthread.php?t=437641

Well after having an addational 3 cells in an 8 cell pack drop to less than 1.0 while the other 5 were still wll above 1.1 V. and haveing others contact me who were also experiencing similiar problems I decided to see what EveryReady had to say about this.

I wrote:

I have purchased and used many AA High Capacity NiMH cells including Energizer 1850,2200,2300 and 2500s. I am an active RC hobbiest and a Amateure Radio Operator so these cells get used a lot. I have never had any problems with Energizers until the 2500s came along. I have had 8 out of 32 to fail in he past year.Most with less than 50 cycles on them.

I just finished retesting 4 which were charged last night and 10 hours latter they only deliver 1700 mAh at a 0.5A discharge rate LVC was set at 0.9V.

Thanks,

Charles

Their responce:

Thank you for visiting Energizer's Web site and also for your inquiry. I am sorry to learn that our batteries did not meet your expectations. I would be happy to assist you.


Because the situation you have described is very unusual we would like to examine those batteries. If you still have the batteries, would you please send them to us? I am sending a pre-paid return label so you can return those batteries at no cost to yourself. You should receive this in 7-10 business days.


Once the batteries are received, you will receive full compensation for that package in the form of coupons.


Once again, thank you for contacting Energizer. If you have any other questions or concerns please feel free to give one of our Customer Service Representative a call at 1-800-383-7323.

Energizer Consumer Relations

__________________________________________________ ____________

As a last minute up date I just place 4 Energizer AA NiMH cells in my LaCrosse at a 500 mA load. The 2300s are over a year old and the 2500 are less than 6 months old I believe.(edit: 11 months old) All cycled two days ago.

2300s one holding 1.17V other holding 1.20V

2500s one at 1.11 and other at 1.10 ( note that in 95% of consumer electronic devices these would have already ceased to work.

These numbers after discharging only 30 mAh from the cells.


I think that since they are unaware of any problems that we should do our part to imform them.

Added a graph with bad # 1 retested fresh off of charge . Charged at 1A ,same rate and same charger as used before.

Post with negative results similiar to mine.

5,9,13,23,27,38, 46 ,74,87,90,125

Charles

Thanks for the tip...

I just called them about my 'Energizer Compact Charger' that failed to charge since new.

Unfortunately I don't have it with me so the nice lady on the phone couldn't do anything to help me, but she told me to get the model number off of the charger and call her back and she'd work with me to straighten out the problem.

Thanks Charles!

-mike s.

I have 24 Energizer 2500 mAH purchased around Nov/Dec '05. They appear to be made by Sanyo (made in Japan, HR stamp on negative terminal, green ring around positive)

One exhibits a high self discharge but tests at 2.40 AH on a BC-900 (500 mA discharge). The rest seem to be holding up fine with low self discharge and 16 cells used in two packs (transmitter cell holders) are staying very evenly matched. The other 8 get used in LED flashlights (.25C 4 cell and .4C 1 cell).

All were cycled new on the BC-900 (750/1000 mA charge) to verify capacities and came up to "full capacity" in a couple of cycles. I initially used the BC-900 for charging them but most of their charges have been on a Lenmar MSC-AA charger that uses a 1 deg C delta temperature per min for charge termination and keeps them very cool. All cells are dicharged to .9 volts every few cycles either in use or on the BC-900 to avoid memory effects. I avoid over discharging them although a few may have been just slightly over discharged as the LED flashlights have regulators that run below .9 V.

I've been keeping a close eye on them after seeing Charle's posts.

Charles, have you tried running any of the cells you're having issues with through the BC-900 refresh mode at a 750 mA or 1000 mA charge rate? I'd be curious if it has any effect. I ran the one cell that exhibits a high discharge rate through a couple of refresh cycle and am monitoring it now.

Mike

I have 16 of the 2300's purchased 2 years ago that are still excellent after many cycles.. I'm glad now I didn't buy any of the "new and improved" lol... 2500's

mabye this explains why a number of my 2500mah energizers seem to be crappy.

Charles, have you tried running any of the cells you're having issues with through the BC-900 refresh mode at a 750 mA or 1000 mA charge rate? I'd be curious if it has any effect. I ran the one cell that exhibits a high discharge rate through a couple of refresh cycle and am monitoring it now.

Mike

The 4 2500 cells in this bad lot of 4 were purchased last Aug. and were cycled several times and left setting for a week to check self discharge rate before being used as a Transmitter battery. During the past 11 months 5 of the 8 cells have went belly up. If refreshed on the LaCrosse BC-900 they will check approx. 2200 mAh charged at 1A discharged at 0.5A but only approx. 1700 mAh if left setting overnight before discharging. Chart which I added to post one shows what they look like after setting for 3 days. The close to 2 year old 2300s which have seen almost twice as much usage also in transmitters are still doing very well.
I have posted many time during the past 8 or 10 months of the problems I have been having with some lots of the 2500s. I feel bad about having recommended them based on my early test results. My 2500 mAh Sanyos are still doing great and I have recently purchased 2700 Sanyos to start fazing out these troublesome Energizer 2500s.


Charles

Interesting. I have a set of 4 2300s purchased two years ago for digital camera use that are going strong. I recently got an 8-pack of 2500s for the same purpose (we have two Olympus cameras that use 4 AA cells each) to replace the worn out Ray-O-Vac 1700s....so far so good, but I admit I have not done any capacity tests. Perhaps I should.

They are not all bad and I have only had 5 out of one package of 8 and 3 out of another package og 8 go bad. Eight out of 32(number purchased) is only 25% failure rate.

Any of these if charged and used right after charging are fine however I am use to being able to charge my Transmitters and fly for hours on end over a period of days or even sometime weeks. THe Transmitter Pack Thread has a test where Sanyo 2500s powered a Tansmitter non stop for over 5 hours after setting for 58 days. These defective 2500 Energizers are self discharging more per hour than they should per day.

Added:

Here is a Snip from a post I made 10 days ago in another thread.

Well a couple of days ago Chris (my son) brought me one of the RC Truck transmitter with the low voltage indicator flashing. Now I knew that the batteries could not really have been ran down that much since last charged . Of the 8 cells 5 were 1.25 to 1.26 per cell and three were 0.90-0.96 volts. This set has what I interpret to be a 2005 date code but as very Ready is very secretive about such I really do not know.

Now all of the Transmitter packs were purchase in packages of 8 cells.cycled 3 to 5 times, charged left to set for 7 to 10 day to check sel discharge rate and kept togeter as a set except for cells which failed and were replaced.

Bothe Transmitter pack which have had cells fail still have some of the original cells which are still doing fine. If it is not a QC problem rhen I am at a lose.

Charles

Gosh man, a friend and I have been experiencing the same thing with these crummy Energizer 2500 NiMH's. We used them for our Aero Ace Tx's and charging. Now I know the that the lower voltage of NiMH's will cause a decrease in range and reaction time of the Tx.

But the real problem lies in how many charges we got out of the 2500's vs regular Duracell Alkalines.

We could only get 5 or so charges to the 150mah lipo in the AA with the 2500 Energizer... where as we can get 11-15 or so charges with the Duracells.

This failure is among other small problems.

Now I know why...

-Chris

Some are very good cells. Here is a recent Graph of a 5 cell battery. These cells are approx. 6 months old so only time will tell.

http://www.rcgroups.com/forums/showp...75&postcount=1

Charles.

First let me state that I realize that no load volts is not a great indication of remaing capacity. Also the amount of charge from a charger to a Ni cell is not a true indication of mAh (capacity) added / replaced.

It is still possible to spot suspect cells by reading no load volts on cells which have been setting for a while . Cells # 1 and #2 in th above graphs checked low open volts and they droped voots very quickly under an approx. 0.2C.

Following the discharges on the first graph (post #1) I recharged all three cells on a La Crosse BC-900. This is a fairly nice 4 channel charger which displaces all data for each cell sperately.

Cells # 1 & 2 had a tested discharge capacity of 180 mAh but required 2,290 mAh to recharge. Cell A had a tested capcity of 1710 mAh and required 2460 mAh to recharge.


As a comparison check .

Eight each Energizer 2500s (a spare Transmitter pack) which was last charged on 7-18-06 ( 15 days ago) and when 4 chossen at random were palced on the La Crosse BC-900 they only required 395 / 510 / 498 / 447 mAh to recharge.This is what I consider normal self discharge.
Tested the remaining 4 cells from this group. 441 / 467 / 409 / 418 mAh

Charles

Hello Charles,

There also have been reports of poor performance from the Energizer 2500 mAh cells among photographers. Some people swear by them, other swear at them...

Tom

I made up four transmitter packs with these cells (2-Optics, 1-Flash 5X, 1-Flash 4X) and I've had to gut two of the four packs within a couple of months to replace bad cells. Each of the two bad packs had two bad cells. The other two packs are still working great.

And before reading this post I thought it was just me...

Jimsky

Deleted dup.

I also thought that it was just an isolted case when I had to replace a cell in one of my Trnasmitter packs, but then another,and another and another. I lost five out of eigh in one Trans. pack and 3 out of eight in another.

It is so very nice of Everyready to sendi out form Email letters proclaiming no non problems or such.

Because the situation you have described is very unusual

Unusual for me to take the time and effort to contact a manufacture with a problem also but enough is enough.
I am sure most are like me and just toss such a cell and take the lose which has allways been my SOP but after about the fourth cell in 5 months or so I started saving them.

I truely which everyone would call or email them.


Customer Service Representative a call at 1-800-383-7323

http://www.energizer.com/contact/default.asp


Charles