I prefer to just be blunt and say don’t piss on my boot and tell me it’s raining. :bigsmile:
LoL true that ILF
It’s like the old saying you can lead a horse to water, but you can’t make him drink. There’s a lot of what if people around the world. My buddy who is more blunt tells those kind of people this when they start doing there if this and if that rant.
If my aunt had balls, she would have been my uncle.
No, it’s. ‘You can lead a horse to water, but but a pencil must be lead!’ :bigsmile:
One other point on Li-ion. I’m not sure if anyone has mentioned it yet, but they are cheaper! 4 eneloops cost me £7/8 where as 1 Sanyo 2600mah with similar power costs me half that.
Marc.
Me too!
Conclusion: Not pampering them anymore, treat them just like eneloops instead! Run them flat to the ground, recharge outdoors under a stone trough tipped over at 1/2C, store fully charged for months, then repeat. Why should I care? They’re living a second life anyways; all of my current 18650s have been harvested from years-old laptop battery packs. Besides, they seem to take the abuse quite well. Still holding their charge, and delivering over one hour of usable light from an XM-L U2 driven at 1.5A. What more could one ask for?
Note: I do not have any torches using more than one single 18650 at a time; otherwise I wouldn’t be so reckless.
I can well imagine that low quality cells are the major worry, but what I’m reading by people far more knowledgeable than I am is making me nervous.
Look at this for example:
“If say your battery terminated at 4.2v [ Normal ] , and after one hour is still holding 4.2v , then your battery is in good shape . If say the battery drops to 4.19v after one hour , then this is rather normal , as would be 4.18v , well within acceptable levels of voltage sag after charging .
Now lets say the battery sags to 4.15v after terminating at a measured 4.2v , then the battery quality - condition is really not so great , and is showing sign of more internal resistance than should be considered normal . If the battery were to sag to 4.12 or lower , then I would suggest replacing the battery or keeping a very close eye on it . ”
Scource:
http://old4570.com/extra/batterywarning.html
What strikes me about this is that we are talking about just hundredths of a volt. The tolerance margins seem slim.
Multi-cell lights appear to be a particular problem, needing a Digital MultiMeter to take battery voltage readings.
You raise an interesting point about laptop batteries.
In order to remain “on topic” without veering off too much, it looks to me as if Li-Ion is still very much the favourite, but that Nickel certainly has it’s supporters, and there may be fertile ground for a certain smallish level of drift away from Li-Ion.
What type of percentage increase in AA cell capacity and brightness are we talking about?
4aa batteries keeping up with one 18650, is not keeping up. Look at the size difference of the batteries 
I’m EDC’ing a Nitecore EA4 at work, and the holster sticks out far enough to make it cumbersome. I love it but its bulky, it’ll be downgraded to a coat light once the thrill of how new it is ends.
I think your too stuck in the details, I check my batteries once per charging cycle, sometimes once per two charging cycles. Batteries that stop holding a solid charge, get disposed of.
If you want to stick to primaries or Nimh, no one is holding a gun to your head.
Just means your flashlight options drop drastically if you limit yourself to one chemistry.
Inside every laptop battery pack is a BMS (Battery Monitoring System). It monitors the voltage on each cell and controls charging and cell balancing. It is the reason laptops don’t blow up more often. Lights that use series connected cells have no such monitoring system. They are a disaster waiting to happen.
And, people, what’s so difficult and onerous about checking a cell’s voltage before and after charging? It only takes a couple of seconds and is well worth the trouble.
Thanks for clarifying that issue. 
BTW, I always move away from Li-ions, and Ti-gers, and Be-ars… oh, my!
I check the voltage after each charge that way I know the battery is working like it should and not losing anything. And if you use them in a series or parallel in a light that takes 2 or more, the last thing you want is to have one at say 4.2 volts and one at 3.8 volts. Now if they are protected nothing should go wrong, but if you know what your charger tops a battery off at and you should if you check them then you know that they returned to their original voltage status and all should be well. There’s not a thing hard or wrong in doing this. Takes a few seconds.
Actually Windows will shut down once it reaches about 5% remaining capacity. If you bypass the OS mechanics, the BMS will shut down the battery pack at a certain point. Rest assured that they chose a safe charge state to do so. ;)
P.S.: Because if you measure the cell fresh from the charger, 1 hour later and maybe a day later you will see if it has suffered. Like someone quoted above, if a cell drops to 4.12V within hours, you should dispose it.
Plus your laptop shutting right down, due to low power, each cell is still around 2.8 volts per cell due too protection circuitry
Nearly all my favorite lights use Li-Ion batteries. I think I’ll be sticking with those for at least the near future.
However, I’m not quite sure what the optimal configuration would be… I have 4x3100mAh unprotected Panasonic NCR18650A in my Skyray King, 2x3100mAh Panasonic NCR18650A protected cells with a narrow button top, 2x3100mAh Panasonic NCR18650A protected cells with a wide button top from Intl-Outdoor, and some 2600mAh Sanyos.
So, I’m not sure if I’m better off using the 4x matched set of unprotected cells in the Skyray King (and the others in 1x18650 lights) or putting the two 2x matched sets of protected cells in the SRK (and using unprotected cells in 1x18650 lights). The two sets of protected cells are the same model, in theory, but are visually different and I’m not sure it’d be okay to use them all in parallel. Conversely, my 4x matched set of unprotected cells are pretty uniform but are being used in parallel. Any idea which config would be better/safer?
FWIW, I generally recharge cells when they get between 3.2V and 3.5V, and try to stop the charge somewhere around 4.10V to 4.15V. With the SRK’s cells though, I make sure to get the charge the same within 0.01V on all cells.
I did not say YOU were. 
I merely pointed out that the great majority of people buying power tools have no idea of how to get the best from the battery.
In fact, if you read my post carefully, I talked about people who drill a few holes now and again and then immediately put the battery back on the charger. ie. The everyday home user who keeps power tools in the workshop and only pulls them out only occasionally. (I would be in this category) That isn't the typical usage profile of someone who uses power tools every day as part of their job. ie. A carpenter, plumber, etc.
My point is that you can leave a NiCad flat for several years with no apparent loss of performance. Leave a Li-Ion cell under 2.0V for a week and you can bin it.
Neither chemistry is ideal for power tools but it's all we have at present.
- A NiCad will self-discharge, but it will survive being flat for long periods. However, it doesn't respond well to repeated cycles of small discharge. It needs to run down periodically to get the best from it.
- A Li-Ion doesn't like being kept at high voltages for extended periods (as happens if you store it in a charger that keeps the voltage topped off). In a hot workshop or garage the problem is exacerbated. They can also be rapidly ruined by being left in a discharged state for relatively short periods of time. I've had enough experience with little-used electronics equipment to verify this as a fact.
- There is no doubt that Li-Ion stores a lot more energy - making for more powerful tools and flashlights. It is also ideal for people using their power tools on a daily basis who are more likely to wear out the battery through use than worry about storage conditions.
In the end guys, this isn't a religious argument and I find it mildly amusing that some people here seem to think they HAVE to choose one chemistry OR the other.
The thread was opened as a discussion of the merits of AA vs Li-Ion cells for flashlights but we seemed to have digressed into a "my battery is better than yours" debate.
Really, they both have their place.
A few months ago I though I’d never use Li-Ion 18650 cells in a headlamp. I now have some of each, and I see a place for each, so I will be living with NiMh LSD AA and AAA Recyko cells (my apologies in advance to all the Eneloop fanboys); LiFePO4 18650, AA and AAA cells; and Li-Co18650’s. I am really starting to appreciate the unprotected 18650 3400 mAh Panny’s, that I carry in the eNB power pack, which protects them while they are being carried to the point where I could not live without them. So I’m resigned to the fact that none any better than the other, and I will be living with all of them into the foreseeable future. I’ve benefited most from this thread in that it taught me about storing them fully charged, which I will now stop doing as much as possible. I’d really like to see some discussion therefore on the ways people approach that in terms of having cells that are ready to go if they need to head out quickly. Sounds like I need to start a new thread with perhaps that as the topic?
Don’t worry about storing them fully charged. In the overall scheme of things, the loss of cell lifetime is not all that significant and not worth the worry and hassle. I have laptops that are plugged in 24/7 and charging the cells all the time. The batteries are years old and still good.
Yeah I’ve done the same to my laptops although I knew it probably wasn’t the best. As I am sometimes on standby for work in the Summer, I will be forced to keep a certain number of cells fully charged and ready to go, so I’m thinking maybe to keep a bundle of ‘EDC’ cells for that, even some of the harvested ones, and pamper my precious 3400 mAH Panny’s for pre-planned multi day backcountry trips where I have to carry everything on my back.
Oh, BTW, thanks for the advice!
Those laptops are used as instrument controllers. The batteries keep them running when the power goes out.
I did not say that you said I was.
As for not thinking Li-Ion is perfect for power tools, I couldn’t disagree more. Until something better comes along they are the most suitable by far. As for not being able to store them, you can store them a lot longer than you think, 5+ years is not uncommon. My best friend is a plumber he had drill Li-ion drill, the charger broke so the drill sat there for 3 years, it had gone flat when he last used it. I plugged the battery pack into my charger and it works perfectly well with no noticeable loss of capacity. You cannot beat that.
Marc.