When do you retire old AA/AAA batteries?

turnipfarmer

Newly Enlightened
Joined
Mar 10, 2011
Messages
41
I've got some old eneloops, which are around 10 years old and their capacity is around 1700mh however when do you guys officially retire an old battery?
 

Kestrel

Flashaholic
Joined
Oct 31, 2007
Messages
7,311
Location
Willamette Valley, OR
Many years ago I had one Eneloop AAA (750mAh) w/ very heavy extended usage; conveyed it to SilverFox, he said its capacity was down to only 150 mAh and did not respond to conditioning.

I do have an unopened 4ct pkg dating to 2006; they were only introduced in November 2005.
On their 20yr anniversary I'll mail them to someone here for analysis, lol.

 

turnipfarmer

Newly Enlightened
Joined
Mar 10, 2011
Messages
41
Cool, cheers guys. My chargers are still charging them but they've lost capacity over the years. Is there any other metrics of the battery that indicate battery health? Eg impedance etc?
 

WC8KCY

Newly Enlightened
Joined
Nov 9, 2020
Messages
34
Assuming your cells are 2000 mAh eneloop and not 2500 mAh eneloop Pro, 1700 mAh is still 85% of rated capacity--perfectly healthy by most any metric.

I have Epson NiMH cells from 1999 that still test out at 80% of rated capacity. Your eneloops may still have years of useful life remaining.
 

jtr1962

Flashaholic
Joined
Nov 22, 2003
Messages
7,502
Location
Flushing, NY
When a smart charger rejects them, I charge them in a dumb charger. I find most "bad" batteries actually still have close to their rated capacity, but only at very low currents on the order of a few mA. This means they can still be used in low-drain stuff like wall clocks or LCD thermometers or remotes.

If a battery gets internal shorts, can't be charged much past 0V, then it's time to recycle it but not before.
 

GaryF

Enlightened
Joined
Apr 17, 2006
Messages
202
Location
Kansas City, MO
I've still got 10 of 12 of my original 2006 manufactured Eneloop AA, and 4 out of of 8 AAA.

2 of the AA failed, one had physical damage, the other developed rapid discharge. I killed 4 of the AAA in a 4 cell radio with parasitic drain that kept discharging them to zero for long periods of time.

My 2006 AA's are down to about 1350-1400mAh, still ok, Mostly they have been used in single or 2 cell devices, and charged before they got deeply discharged.

17 years is pretty amazing.
 

letschat7

Flashlight Enthusiast
Joined
Dec 7, 2022
Messages
1,975
Location
West Virginia, North America
I have an Apple Eneloop that doesn't work right. I keep it in the recycle bin.
 

Attachments

  • EF511D79-422D-48AA-A03B-294D6502AED4.jpeg
    EF511D79-422D-48AA-A03B-294D6502AED4.jpeg
    970.5 KB · Views: 37

cave dave

Flashlight Enthusiast
Joined
Aug 15, 2001
Messages
3,740
Location
VA
I have a graphing calculator that uses 3xAAA. It's pretty low drain and new good Eneloops will last a year. If they get so bad that they only last 2 mo its time for them to go. I also use ones that won't charge in a smart charger in rarely used remotes, and they seem to last till I charge them at the spring and fall time changes.
I think things like calculators, remotes, wireless mice can be pretty rough on cells though because they can drain them down to nothing while still working OK.
 

ampdude

Flashlight Enthusiast
Joined
Apr 7, 2007
Messages
4,513
Location
USA
AA and AAA rechargeable batteries typically don't leak, so I just use them until they give no power any more or the charger won't charge them like the original response to this thread mentioned. Until just recently I still had some Nicad's from the late 90's that still worked fine. NIMH batteries usually have a pretty short life span.. shorter than lithium ion batteries. I'm surprised you have some ten years old, none of mine have ever lasted over 4-5 years. I have some AW lithium ions that are over 12 years old and still going strong and still very consistent.
 

Wrend

Enlightened
Joined
Oct 14, 2010
Messages
646
Location
United States, IL
They're rated down to 80% remaining capacity. At this point they tend to degrade exponentially, but yes, if they still work for you, then they still work. I still have all my Eneloops from 10+ years of buying them and haven't bothered testing their capacity very accurately as they still all hold a charge and work. However, I have taken some series sets apart when a cell stops performing as well as the others, so I have a few individual cells from those. They still work in single cell applications for me. They all still charge fine for me. I use them in rotation and have extra sets charged and ready to use. This is how I store them and generally I do not top them off again before use. It may be that one of these years I'll have several fail on me, but no sign of that yet. Cheers.
 
Last edited:
Top