Adhoc/unexpected long term self-discharge test of Eneloops..

[Closet_Flashaholic]

So,
Last Friday I took delivery of, among other things, 16 eneloop AA batteries. I was disappointed that the date stamps of all 4 packages were 2006-09 Indicating that the batteries have been on the shelf for 20 months +/- 1 month. I chose to look at the bright side of things and see how much capacity they had after 20 months. Here are the results:

Using C9000 (original firmware rev. - whatever that was):

Group 1:
1436
1425
1433
1427

Group 2:
1415
1415
1405
1440

Group 3:
1447
1437
1414
1436

Group 4:
1454
1462
1469
1453

I am conditioning them now and if anyone is interested, I will report back the capacity after the conditioning is done. I am also checking on other ones that I have kept at 33 degrees F for 6 months and see what their capacity is.

I don't know if the store I bought them from has a huge supply of these, or whether Sanyo has a huge supply of these, or if they just aren't selling the number that they anticipated and have a huge stockpile. Does anyone have any info on this? Please don't speculate, unless you have at least some hard data to back it up.

Thanks.

 

[warlord]

I just picked up some AAA's with the date code 08-2006 from CC. The packaging was slightly discolored yellow, too.

 

[45/70]

This has been discussed numerous times before, but anyway, all the eneloops I've heard of, to date, are 2006.

Dave

 

[Bones]

These threads reference the Eneloop's date of manufacture Closet_Flashaholic:

http://www.candlepowerforums.com ... post2433392

http://www.candlepowerforums.com ... post2322060

This one references its initial capacity right out of the package:

http://www.candlepowerforums.com ... post2043113

 

[Mr Happy]

Extra data never hurts. The consistency of those numbers is quite remarkable given the long time in storage.

I get the impression that the self discharge slows to a very slow rate indeed after about 1 year.

I have some unopened 2006-09 Eneloops myself. I did have some 2006-05 ones, but I opened and used those some time ago unfortunately.

 

[Closet_Flashaholic]

These threads reference the Eneloop's date of manufacture Closet_Flashaholic:

http://www.candlepowerforums.com ... post2433392

http://www.candlepowerforums.com ... post2322060

This one references its initial capacity right out of the package:

http://www.candlepowerforums.com ... post2043113

Thanks for the info,
I guess I should have done a more thorough search before posting a new thread.. I should have known that CPFers would have addressed this ad infinitum....

Interesting threads none-the-less. I don't have a problem with the older cells as long as they keep working. I have Sanyo 1600 NiMH probably 6-7 years old that still have great capacity and have definitely paid for themselves many times over. Let's hope the eneloops are as good, over the long term.

I have been keeping some of my eneloopes in the fridge (33F) as a test just to see if the self-discharge can be lowered further. We'll see.

 

[Aluminous]

I am conditioning them now and if anyone is interested, I will report back the capacity after the conditioning is done. I am also checking on other ones that I have kept at 33 degrees F for 6 months and see what their capacity is.

I am interested to hear your results.

 

[45/70]

Thanks for the info,
I guess I should have done a more thorough search before posting a new thread.. I should have known that CPFers would have addressed this ad infinitum....

Um, hey Closet_Flashaholic, your right of course , but just for the record, I wasn't harassing you for your post. Kinda looks like it when I reread my post. That was not my intention. I don't think Bones was either, just pointing out where it had been discussed. And, as Mr Happy pointed out, all information is useful.

Hey, I even learned there are 2007 eneloops! :naughty:

Dave

 

[Handlobraesing]

Anyone had issues with eneloops escalating in internal resistance after extended storage at full charge?

I had a set of perfectly good fully charged eneloop stored in my camera bag in a side pocket, not installed in anything and when I went to use them, they seemed dead, but had ~1.3v but very high internal resistance.