some of my 5 year old AAA eneloop pro are half as bright in my Lumintop AAA Tool, as my same age eneloop…
so I bought a few more non-pro
I cant measure capacity, but I do have a light meter, so I can compare different battery outputs in the same light.
11 years. decent shape.
I have 4 gen1 AAA sanyo eneloops manufactured 12-2007, used for high current (flashlight) but infrequently, so definitely <50 cycles.
Charged in BC700, always at 200mA before I knew better 
Capacity still seems fine, the worst one has 85% left but all of them have developed high internal resistance.
They can only be used in low-drain devices now but 13.5 years is beyond impressive.
Sadly I have no meter for measuring the internal resistance.
My old eneloop are still fine, about 6 years old. Mostly used in RC toys and flashlights.
They hold up fine, I think.
worth the money.
i have some first gen from 06 in a solar light.
recently tested at 1781-1784 @ 1a.
great for a set in use cyclically every day for 10 years.
ir 60mohm.
new are around 30.
i just opened a set of duraloops from 11.
1.31v all 4.
out of the pack they gave 1123-1125 1a after 2 cycles i got 1887-1891 1a
9/2011.
Chris
This thread had me wondering about some of my Eneloops— I tested some random singles I had at 800 ma discharge
Sanyo 11/13 ——- 1773 / 1790
Panasonic 5/16 ——— 1585 / 1773
I do not understand how to measure batteries performance, and I do not understand the meaning of several of the posts with IR numbers in them
can you explain what measurements give what info, what does IR tell you?
does higher IR correlate with Lower Lumen output?
my experience is after 5 years of light use, zero abuse, my Eneloop Pro produce half as many lumens in my aaa Tool… than they did when new. but I dont know how to measure IR, so I dont know if those two factors, higher max output, and Lower IR, are correlated
factual, measurement based education welcome…
can you summarize this thread, to tell me what you learned?
Batteries/cells develop high internal resistances over time and as a result, they tend to self-discharge more, don’t output the same current as when new and become harder to charge, to the point that many consumer chargers will reject them due to crappy power supplies. Some dumb chargers can force charge high I.R. batteries, but it’s a losing proposition.
Analyzing chargers with internal I.R. functions are flaky at best and the ‘number’ should rarely be viewed as gospel, but it does give the user a sense for comparison purposes.
Chris
thank you
does high IR also reduce runtime?
I cant measure IR, but I can measure lumens. I dont usually worry about runtime, so have not checked…
though my old eneloop pro AAA in my Lumintop Tool, dont reach 50% of maximum anymore, the low and medium modes work normally…
so I think people with old batteries in low drain devices like remote controls, or flashlights with low output levels, will not notice when an old eneloop is no longer able to support maximum output, since those low drain applications dont have such a high demand for power. Does that make sense?
I have some really old Eneloop white (circa 2007-2008), and back then I didn’t know how to charge them so they last longer — I bought a GP 1-hour rapid charger to charge them since I thought a fast charger will be good when I need batteries to charge faster (my only other NiMh charger back then was a very slow ~8-12 hour standard charger which I find too slow).
I recall the NiMh batteries do get very hot while charging, so these likely reduced those old Eneloops.
When I got the SkyRC MC3000 about 2 or 3 years ago, using the DC IR resistance check function, they read ~2000-3000+ mOhms.
Using the YR1030 AC IR resistance test, these also have like 5Ohms (ie. 5000+ mOhms).
A new Eneloop I bought in the last few years (not abused / charged at very high charge current), the DC IR from MC3000 will read below 100mOhms
YR1030 AC IR of the new Eneloop will be somewhere from 20-30mOhms.
When used in a flashlight, eg. Tool AA:
- new Eneloop works fine with Tool AA, there is a difference between Low and Medium and High , which are distinctly different brightness
In terms of capacity, I believe my old Eneloops still have fairly good capacity providing the discharge current is very low (eg. below 0.10A). Any higher than 0.1A and the voltage will drop a LOT.
Unlike the newer Eneloops which work well even at higher current like 1.0A
thanks!
that is very helpful info
it provides a way to know when a battery is failing, without measuring IR, and without measuring lumens… if the battery can no longer support a normal High Mode.
I have the same result with a Tool AAA, the lower modes still make the same lumen output as a new eneloop, but the high mode is only slightly brighter than medium, with my old tired eneloop
I have two sets from 2012 that probably have over 100 cycles on them that are still working fine.
Haven’t noticed any reduced runtimes on my d40a.
Wow one of the members from when I first joined BLF —- Good to see you’re still around
Just found my 2 eneloops from 2008 in my nieces old point and shoot. I’ve been reconditioning them on a maha they give me about 40 minutes of light on a 2 aa xeno es2 on med. after a few minutes on high I left it on med then 5 minutes later they refused to go on high. They might be coming back to life
my gen1 AAA eneloops from 03/2007 have between 850 and 2880mOhm, maybe 50 cycles total
curiously my gen1 AA eneloops from 02/2009 have 40-49mOhm
Aaa high capacity cells in particular tend to be less abuse tolerant.
Too many chargers charge them too fast.
Standard eneloops/duraloops/ikealoops tend to last the longest for me even when i drop them into the c9000 at its default 1a charge.
I think the eneloop pro aaa i had got 50 cycles before being demoted to solar lights.
Then they worked 2 years before they were done.
Esr over 99 ohms.
Thats the highest the dick smith esr recognizes.
My first led light (Sept. 2011) was a Sunwayman D40A. First light with an XM-L (600lm). The day I got the light I put black Eneloop AA Pro’s in it. Today this combination is still going strong.
I initially bought 8 AA Eneloops in 2006. All 8 are still going strong.
Best money I ever spent on batteries.
I got the 2 four packs for $4 a pack on Close Out at a WalMart.
They would not sell because nobody knew what these “expensive” batteries were.
Fortunately I had a photographer friend who had told me about them.
I was just sad they only had 2 four packs.
Still have the same set in my 2C mag!