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Thread: How often do you need to recharge batteries in moderate use lights?

  1. #1
    Flashaholic* HighlanderNorth's Avatar
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    Question How often do you need to recharge batteries in moderate use lights?

    If you are a police officer or a security guard or work in a similar position where you regularly use your flashlights, and you use rechargeable batteries in them, you will probably only need to recharge them once they run way down or go dead, or the built in regulation in the light bumps the high setting down to medium due to your batteries being low.

    But if you are like many people here, like me, who have multiple lights, and you dont use a single light all the time, so you have lots of lights that get only occasional use, how do you determine when to recharge the batteries? I know there are now some low self discharge NiMh batteries on the market, and I have bought a bunch of Eneloop AA and AAA's, which will hold their charge for a long time even when not in regular use, but what about the Li-Ion 18650's, and the 14500's, and 16340's, etc?

    If I only use each light for a total of maybe 20 minutes per week, or less, as I switch from light to light, then it is going to take a long time to run the batteries dead, especially since I rarely use high or turbo brightness settings. I use the 30-50-100 lumen settings most of the time, and most lights will last between 6-18 hours on those settings if you run the lights that long. But it will take me a long time to run any of these lights 6-18 hours, because I only a flashlight for about maybe 20 minutes total per day, and I switch back and forth between lights. So I might only run any 1 of these lights for about 15-20 minutes per week, because I now have 10 of them to choose from, and I switch around. So for me to run a single light for 6-18 hours could take many months(unless I take one on a backpacking or camping trip, then I will use that light for several hours in a few days).

    How long do Panasonic based 18650's hold their charges if not used regularly? How about Eagletac 14500's or 16340's? The main question is, should I occasionally top them off on the charger even if they arent run down? How often to do that, and will it have a negative effect on their lifespan?

    Thanks in advance...

  2. #2
    Unenlightened
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    Default Re: How often do you need to recharge batteries in moderate use lights?

    i know about 18650 li-battery, i have a flashlight camera which is powered by 18650 li-battery. it can be used about 3 hrs for strong light, and 9hrs for soft light.

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    Flashaholic* ChrisGarrett's Avatar
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    Default Re: How often do you need to recharge batteries in moderate use lights?

    I'm surely no expert, but I've been playing with Li-Ion 18650s, 14500s and 16340s for a couple of months. I have six, or seven EDC lights that I just fiddle with and rotate through, so I'm not using them everyday. However, I'll get the DMM out and check them after I use one a bit and if my cells are in the 3.8-3.9v range, I'll throw them on the charger.

    I've been told that if you're not going to be using your cells for ~3-6 months at a stretch, drop them down to 3.8-3.9v and store them in a zip lock in the fridge.

    I've got 2 EagleTac 3100s in there right now, cause I'm just not using the Fenix PD32 and ZL SC-600 all that much and they both have the unprotected Pannie NCR18650A installed. I'll eventually run them down a bit and then top them off, just to keep them exercised.

    Same with the four 14500 Sanyo 840 mAh cells that I have. With one light, they're not getting used that much, but I rotate them in and out and just run them a bit. With Li-Ions, it's not a matter of cycles, but rather 'time' that eventually slows them down, so there's no harm in running them down a bit and charging them up.

    My two Soshine 700 mAh 16340s get used more, they being for the SWM V10R and ShiningBeam I mini, which are both neat little lights, so I just top them off every few days.

    My NiMH LSD/HSD batteries are a bit more problematic in basic useage, but again, I stick them in a light and just run them down a bit, then charge them back up.

    Chris
    Convoy: S2, M1, M2, Fenix: P1D, PD32, HL30, ET: D25C Ti, SF: 6P, ZL: SC-600, Klarus: P2A, Jetbeam: BA-20, Icon: Rogue 1, L3: L10, Xeno: E03, ShiningBeam: I-Mini, Olight: i3s, SWM: D40A, M11R, V11R, Maglite: 6Ds, MMs, Solitaires, LaCrosse BC-700, Maha C-9000, XTAR VP2, MP1S, WP2 II, NiteCore i4, v2.

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    Default Re: How often do you need to recharge batteries in moderate use lights?

    assuming that "moderate use" means that the cell(s) were not used to a discharged or cut-off condition, then I have the following use: For routine or daily used lights, I swap out the cell(s) daily and charge them. Lights used, but not really daily such as the SC600, have their cell swapped out and charged weekly. The larger lights (TK35 or V60) have their cells removed (swapped out) and charged monthly. I have a very strong aversion to a protected cell cutting out while I am using it, hence the slight neurosis with freqent charging. most of my lights are single cell lights, either AA/AAA or 18650. I disposed of all RCR123 cells.

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    Flashaholic* HighlanderNorth's Avatar
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    Default Re: How often do you need to recharge batteries in moderate use lights?

    Quote Originally Posted by ChrisGarrett View Post
    I'm surely no expert, but I've been playing with Li-Ion 18650s, 14500s and 16340s for a couple of months. I have six, or seven EDC lights that I just fiddle with and rotate through, so I'm not using them everyday. However, I'll get the DMM out and check them after I use one a bit and if my cells are in the 3.8-3.9v range, I'll throw them on the charger.

    I've been told that if you're not going to be using your cells for ~3-6 months at a stretch, drop them down to 3.8-3.9v and store them in a zip lock in the fridge.

    I've got 2 EagleTac 3100s in there right now, cause I'm just not using the Fenix PD32 and ZL SC-600 all that much and they both have the unprotected Pannie NCR18650A installed. I'll eventually run them down a bit and then top them off, just to keep them exercised.

    Same with the four 14500 Sanyo 840 mAh cells that I have. With one light, they're not getting used that much, but I rotate them in and out and just run them a bit. With Li-Ions, it's not a matter of cycles, but rather 'time' that eventually slows them down, so there's no harm in running them down a bit and charging them up.

    My two Soshine 700 mAh 16340s get used more, they being for the SWM V10R and ShiningBeam I mini, which are both neat little lights, so I just top them off every few days.

    My NiMH LSD/HSD batteries are a bit more problematic in basic useage, but again, I stick them in a light and just run them down a bit, then charge them back up.

    Chris

    How long have you had your Soshine 16340's, and how often do you use them, recharge them? Any problems?

    I bought 2 of them about 4-6 weeks ago, but havent used them hardly at all, because I expected them to make my D25C brighter, but it didnt happen, and I tried them in my Solarforce L2P but they didnt make that brighter either, so there's no point in using those batteries right now.

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    Flashaholic* HighlanderNorth's Avatar
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    Default Re: How often do you need to recharge batteries in moderate use lights?

    So if it isnt really going to hurt my Li Ion batteries to charge them here and there even though they arent really run down, then I'm going to do it once every 2-4 weeks from now on.

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    Default Re: How often do you need to recharge batteries in moderate use lights?

    Every few weeks I recharge my Eneloops for primary flashlights & game controllers. Maybe every three months (or before a big storm come in) for my secondary lights. I cycle my batteries between lights every year. I will check voltages on my Li-ions during my general battery charge routine.

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    Default Re: How often do you need to recharge batteries in moderate use lights?

    Quote Originally Posted by edpmis02 View Post
    Every few weeks I recharge my Eneloops for primary flashlights & game controllers. Maybe every three months (or before a big storm come in) for my secondary lights. I cycle my batteries between lights every year. I will check voltages on my Li-ions during my general battery charge routine.
    With my Li-Ions , I "guestimate" how much useage they get and then top them up ... I am usually on the right side in my estimations and the Li-Ion voltages are showing that there is still about 50% charge left.

    My LSD AA's and AAA's are kept at room temperature in my desk drawer and are charged regularly ... They were all charged on 28th June 2012 and before that they were last charged on 25th March 2011 ... Before that , they were topped up on 25th November 2010 ... I must have forgotten to charge them towards the end of 2011 ... With my Eneloops , a simple top up every six or nine months is perfectly OK.

    So , I forgot to charge them for 15 months ... In all fairness , it didn't take too long to fully charge them ( top-up) all on 28th June 2012 ... Unfortunately none of my chargers can measure the capacity of my cells and on another thread I am looking for information on a couple of the cheaper intelligent chargers that I noticed on Ebay.

    Certainly the LSD cells have made things a lot easier for charging AA and AAA cells ... They really do retain a very large percentage of their capacity even after the 15 months of my example.
    .

  9. #9

    Default Re: How often do you need to recharge batteries in moderate use lights?

    Quote Originally Posted by HighlanderNorth View Post
    So if it isnt really going to hurt my Li Ion batteries to charge them here and there even though they arent really run down, then I'm going to do it once every 2-4 weeks from now on.
    Which means that you'll have to consciously run the lights weekly for about a 1/2 hr just to get them down to 'chargeable' level. I'm in the same boat as you...by having lights I use less than others, but hadn't considered a program such as that, just to keep them 'exercised'.

  10. #10

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    Quote Originally Posted by HighlanderNorth View Post
    How long do Panasonic based 18650's hold their charges if not used regularly? How about Eagletac 14500's or 16340's? The main question is, should I occasionally top them off on the charger even if they arent run down? How often to do that, and will it have a negative effect on their lifespan?
    Might be worth reading this:

    http://batteryuniversity.com/learn/a...ased_batteries

    From my understanding, what you're doing basically amounts to storing a cell. And after heat, the greatest wear factor on a Li-ion is high voltage... both charging to 4.2V and then letting it sit there at that level for long periods of time.

    The two things I would try and do are 1) simply stay with a primary and backup batt of each core size and then rotate your lights around them, leaving no batteries in the lights out of current rotation and/or 2) terminate your charging at say 4.0V and recharging at say 3.7V so the light is averaging out at middling capacity level.

    But that's if you really want your batteries to last, and it may not be worth the effort. Even if you keep topping them up, they'll last for a few years and then you can just buy new ones.
    Last edited by reppans; 06-29-2012 at 09:32 PM.

  11. #11
    Flashaholic* HighlanderNorth's Avatar
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    Default Re: How often do you need to recharge batteries in moderate use lights?

    Quote Originally Posted by reppans View Post
    Might be worth reading this:

    http://batteryuniversity.com/learn/a...ased_batteries

    From my understanding, what you're doing basically amounts to storing a cell. And after heat, the greatest wear factor on a Li-ion is high voltage... both charging to 4.2V and then letting it sit there at that level for long periods of time.

    The two things I would try and do are 1) simply stay with a primary and backup batt of each core size and then rotate your lights around them, leaving no batteries in the lights out of current rotation and/or 2) terminate your charging at say 4.0V and recharging at say 3.7V so the light is averaging out at middling capacity level.

    But that's if you really want your batteries to last, and it may not be worth the effort. Even if you keep topping them up, they'll last for a few years and then you can just buy new ones.


    That^ brings up another issue that I am trying to resove in another thread. My current charger is great in that it can recharge both Li-Ions and NimH and NiCd, but it has no LCD screen that tells me the voltage or anything else. It just supposedly charges them to where they should be. I need a good smart charger that DOES let me know the current voltage and other info, for my LiIons and my NiMh batts, but I dont think I'll find one that does all 3 battery types.
    Last edited by HighlanderNorth; 06-30-2012 at 10:37 AM.

  12. #12
    Flashaholic* HighlanderNorth's Avatar
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    Default Re: How often do you need to recharge batteries in moderate use lights?

    Quote Originally Posted by reppans View Post
    Might be worth reading this:

    http://batteryuniversity.com/learn/a...ased_batteries

    From my understanding, what you're doing basically amounts to storing a cell. And after heat, the greatest wear factor on a Li-ion is high voltage... both charging to 4.2V and then letting it sit there at that level for long periods of time.

    The two things I would try and do are 1) simply stay with a primary and backup batt of each core size and then rotate your lights around them, leaving no batteries in the lights out of current rotation and/or 2) terminate your charging at say 4.0V and recharging at say 3.7V so the light is averaging out at middling capacity level.

    But that's if you really want your batteries to last, and it may not be worth the effort. Even if you keep topping them up, they'll last for a few years and then you can just buy new ones.


    According to batteryuniverstity, its actually better to recharge Li-Ion batteries after they've only lost a smaller amount of their total capacity than it is to run them all the way down or almost all the way down. Its obviously not good to discharge them 100%, but its better to discharge them only 20% then recharge them, than it is to discharge them 50% and recharge them every time. Its also apparently good to only charge them to about 4v, instead of all the way to the max of 4.2v. But not to let them drop below 3.7v.


    So if we can somehow keep track of volts and capacity, and recharge them when they've only discharged 20-30% each time, they will last through many, many more cycles then if they were 50-70-100% discharged every time.

    This now makes me realize that I am now doing something with my spare 18650's that I shouldnt be doing. I thought it would be a good idea to buy 2 spare Panasonic based 18650's, and store them in my Pelican 1050 case for future use just in case I need them. So I fully charged them and they've been sitting in there for almost a month now unused. I will have to start cycling them and rotating them into my lights.

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    Default Re: How often do you need to recharge batteries in moderate use lights?

    What you are finding is exactly why I try to use lights that can run on "either" primary (energizer AA Li or CR123s) or recharge cells. In a moderate power flashlight that is lightly used, a consumer grade Li primary cell will last for many years, ready to go when needed.

    A forgotten flashlight with R type cells is as likely as not to be marginal when needed most, especially when it is cold outside, but there is nothing like R cells for heavy use or power lights..

  14. #14

    Default Re: How often do you need to recharge batteries in moderate use lights?

    Quote Originally Posted by HighlanderNorth View Post
    According to batteryuniverstity, its actually better to recharge Li-Ion batteries after they've only lost a smaller amount of their total capacity than it is to run them all the way down or almost all the way down. Its obviously not good to discharge them 100%, but its better to discharge them only 20% then recharge them, than it is to discharge them 50% and recharge them every time. Its also apparently good to only charge them to about 4v, instead of all the way to the max of 4.2v. But not to let them drop below 3.7v.
    I won't dispute this, but find this method most challenging when using 16340's. In some cases they won't last 30 mins in a light. So it's hard to imagine after using a freshly charged cell for 10 mins...that it would need charging again! -- which is why in most of MY scenarios...the circuit will trip, and I'll be in the dark with a spare somewhere else! This is especially noticeable when using 2 RCR's in the Maelstrom G5!

    Much easier with 18650's, to follow such a regimine.
    Last edited by RBWNY; 07-03-2012 at 09:53 AM.

  15. #15
    Flashaholic* HighlanderNorth's Avatar
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    Default Re: How often do you need to recharge batteries in moderate use lights?

    Quote Originally Posted by RBWNY View Post
    I won't dispute this, but find this method most challenging when using 16340's. In some cases they won't last 30 mins in a light. So it's hard to imagine after using a freshly charged cell for 10 mins...that it would need charging again! -- which is why in most of MY scenarios...the circuit will trip, and I'll be in the dark with a spare somewhere else! This is especially noticeable when using 2 RCR's in the Maelstrom G5!

    Much easier with 18650's, to follow such a regimine.

    I bought 2 16340's and I dont even use them. The capacity is not so good, and the only use for them in my lights would be to get the extra turbo brightness, which isnt that important, and it will run them down in a big hurry! I cant see using a 16340 and only running it down to 70% capacity so that it will last through more charge cycles! You'd need to recharge them after like 4 minutes of use! No thanks......

  16. #16

    Default Re: How often do you need to recharge batteries in moderate use lights?

    Quote Originally Posted by HighlanderNorth View Post
    I bought 2 16340's and I dont even use them. The capacity is not so good, and the only use for them in my lights would be to get the extra turbo brightness, which isnt that important, and it will run them down in a big hurry! I cant see using a 16340 and only running it down to 70% capacity so that it will last through more charge cycles! You'd need to recharge them after like 4 minutes of use! No thanks......
    This is true....but like I said, I normally just use `em until they croak. I see no point in not using them...since I have about 14 of them, because in lights that take them, it's far more economical than using primaries!!

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