Hello and Welcome to BLF, Steve!
Confirming above. Usually AA's charge to right around 1.449 almost every time. Settle in to around 1.39-1.41 after a week or so.
Thanks for the quick reply and the warm welcome! It sounds like my cells are terminating properly. I'm using the Sony BCG-34HLD charger I picked up based on the test in the charger forum and it seems to work great on all 4 channels. Soooo....when my cells reach .9 to 1.0 volts I should consider them empty? Sounds good to me. I just picked up an Eagle Tac P20 A2 MII as a backup to my Eagle Tac T20 C2 MII. I carry both of them when I'm on my bassboat. I got it for 49 bucks shipped. Normally 65 bucks.
Cone, I'm in south Jersey right now! I'm doing some inspection work at the Hope Creek Nuclear plant......
Yep. However I would recommend not running them down that far because as I understand that shortens the batteries life. (cycles not mah) However considering they're rated for 1500 cycles if you recharge them once a week they would last 28 years. (1500/52) So you probably don't need to worry. Wow I just disproved myself. ;) Nice lights btw. :)
Scaru,
I was really surprised at how little difference there is between the P20 and the T20. The P20 is an XPG-R5 at 300 emitter lumens and the T20 is an XML-T6 at 720 emitter lumens. They're almost the same. When I get home, I need to go test them out because I get the feeling that the P20 might out throw the T20. The T20 is realistically good out to maybe 75 yards, regardless of what Eagle Tac claims. It suits my needs tho because I need a flooder at the boat ramp. If I want to "reach out and touch somebody" I get out my Solarforce 2X18650 with the Masterpiece 1 R2 thrower head on it. That thing must throw a good 300 to 350 yards, but I haven't done any scientific testing. Later!
Really? You're not a diver, are you?
Nope, are you working there?
No, but I do work around power plants and other similar infrastructure, You know, fun places that require FR coveralls, dialectric boots, TWIC cards, and other fun stuff depending on the day.
Aloha and welcome to BLF Steve P.!
Here is a charge curve for a eneloop, the terminates is around 1.53 volt, but it drops to 1.45 volt in a short time.
HKJ, you got the i4 V2 charger!!?
Yes and I am nearly finished with testing. Generally I does fine on LiIon, but I wonder about the termination on NiMH, it does not look like -dv/dt.
Thanks, HKJ, always fascinating to see your graphs. I was charging a few AAA eneloops overnight anyway, so thought I'd post readings off my dmm:
1.502 - off the charger
1.495 - 5 minutes
1.490 - 10 minutes
1.488 - 15 minutes
1.485 - 20 minutes
1.482 - 25 minutes
1.480 - 30 minutes
1.475 - 45 minutes
Now I’m clear on termination voltage and where it settles down to. Also, .9 volts is considered “EMPTY”, correct? What is the suggested voltage reading where I say, hey, I need to charge these things? I guess I’m asking what’s the minimum voltage I should normally run these down to?
Yeah .9 volts should be considered empty.
Welcome to BLF, Steve P.
anyone feel free to correct me if smarta$$ me talks bull$hit but here's my take anyway...
For example we're talking of Eneloops 800mAh AAA: then the very lowest you can get (e.g. after 850mAh discharged capacity) UNDER LOAD is 0.8V (~0.81-0.82V, typically it's more like 0.83V).
this is UNDER LOAD.
let this Eneloop cell rest for 2 3 hours, or 23 hours or whatever. the voltage will recover (but the cell is still empty of course!) to, say, 1.10V minimum. This voltage is called "resting voltage", "voltage at rest", or i call it "offline voltage (at rest)". Believe me, you will NEVER find an Eneloop at rest, which has your quoted "0.9V". At rest, the Eneloop (if it is 100.1% depleted) will have at least 1.10V.
What does the C9000 do? It discharges (slowly) down to 0.9000V (cell is maybe 95% empty by then) and then let it rest for 1 or 2 hours. during that time (e.g. the 2.0 hours) the cell recovers to 1.2000V (pretty much exact this number). In other words, a NiMH cell with 1.20V resting voltage is considered "empty" by the C9000. The truth is, it's possible to quench out even more capacity (with electronic gadgets or flashlights with superlow current draw) such that the resting voltage approaches the 1.10V. If you do this hardcore overdischarging too often, you probably hurt the Eneloop cell in some way ("aging") although i cant confirm this because Eneloop cells tolerate all kinds of abuse.
*If* you do find Eneloops at rest which show 0.80 or 0.90V on your DMM, then your DMM is either is kaput, or i will call you a liar haha or your the first Eneloop owner in the world who managed to produce such a resting voltage state, world-premiere!! (the probability that your Eneloop cell is broken and that be the reason why you get such an otherwise impossible DMM reading is practically zero because Eneloops are robust in many respects.)
In summary, if you know that your Eneloop cells are okay (not broken), then at discharged state (e.g. up to 850mAh discharged for Eneloop AAA) and at rest, you will never see 0.8, 0.9 or 1.0V. Never. 1.10V is the lowest you could measure. More typical voltages are between 1.16 and 1.20V; if your DMM reads 1.20V (at rest) or lower, then it's time (and not too late yet! :) ) to recharge the cell.
hope this helpz.
I think this is bullshit. I don't have any eneloops, but it is just a NiMH cell; I have measured 0.9 or so on a NiMH cell.
Imagine you measure your empty 1.1V cell every day; the voltage eventually will go to 0V. Gradually.
thanks for your opinion 
ive been doing EXTENSIVE runtime testing on Eneloops on Hi, Med, and Lo. More than anybody else on cpf or blf, believe me. When a 800mAh Eneloop AAA is TOTALLY depleted (99.x%) say in Moonlight mode and you take it off the charger, the cell shows 0.8xV (e.g. 0.82V) and it would recover very slowly to 1.1xV (e.g. 1.14V) within 24 hours.
Well, we're talking about practical situations: i dont know what happens with the resting voltage of the original Sanyo Eneloop (t = 0.1sec, V(t) = 0.83V; t = 1day, V(t) = 1.14V) if you let it rest even longer, say t = 5 yrs, V(t) = ?.??V.
I own super expensive NiMH LSD cells (Varta LSD, 4€ apiece AAA), and they show a TOTALLY DIFFERENT discharge behavior and other behavior which means that Eneloops are indeed VERY SPECIAL cells in every regard.
Probably true, after 5 or 15 yrs the Eneloop cell (if stored at depleted state) is dead. kaput. and it then eventually has to cross the 0.9V mark haha.
In any case if nobody else did as much extensive testing of Eneloop cells in their depleted (and totally depleted) state, then my word be da truth until someone comes up with youtube video proving the opposite.. :p
(I think it would not be years). Just add a little discharge, less than your moonlight mode. If you can get the cell from 1.2V to 1.1V, you can also get it to 1.0 or 0.9 or 0.8, just use less current. You could even connect the cell to a stable 0.8V, then disconnect a week later. I think it would stay at 0.8V then.
The cell should not be dead, if discharged to 0V. Polarity reversal is what kills them.
good info, thanks!!
i dont have much knowledge about batteries but i did much observing of my Eneloop cells and since the OP was asking about practical info or typical situations, i was able to give helpful info. Typically, people do *not* discharge their cells further than after dimming has begun (~0.90V under load; the C9000 cut off mark) and even less people do runtime tests on Lo, super Lo or Moonlight modes, especially not on their expensive Eneloop cells. The 3rd gen Eneloops keep their charge even longer and that makes this discussion harder because any normal user who buys them (to use them of course!, for normal purposes!! and not testing runtimes on Moonlight mode) would not measure resting voltages below 1.15V.
Eneloops are very special, that's all i wanted to convey. ;)