How and when do you charge your cells?

Hi guys! Newbie here. I just got my first FL, a Klarus xt12gt, it comes with a KLARUS 18GT-36 18650 cell.

So my question is, how/when do you charge it? I mean do you totally drain the battery or maybe up to 20% then charge to 100%? Or do you do the 60% - 80% charge method the same as mobile phones?

Reason is because I read somewhere that the rechargeable battery cells have limited "charging cycles" (lets say 1000 charge cycles for a brand new one). So what happens is, when you charge it to full every time, the charge cycle number lessens. Thus, this method of charging it when it is 60% then only up to 80% therefore "prolongs" the charge cycles for the particular cell.

Now my dilemma is, that when you don't charge to 100%, you won't get that max lumens output, correct me if I'm wrong please. But then if you charge to a 100% all the time, you lessen the charge cycles.

And one last question, is it better to charge the cell inside the FL? Or is it better for me to buy a separate charging device and charge the cell outside the FL? If so, what brand would you recommend for the KLARUS 18GT-36 18650?

Please share your thoughts, advice and or charging habits. Thank you so much in advance.

I prefer to charge outside the light, however the built in USB can come in handy for when out and about(car for example). There is no memory with the cell, so use, top up, repeat. Would not worry too much on using 20% to 80%, kind of kills actual enjoyment and too much faffing around to get a few more cycles of life on a $6 cell. Usually cells can be 300-500 cycle life(think to 70% capacity iirc...........)Any way, topping up from say 3.6v is not a full charge cycle, so in effect you could end up topping off 600-1000 times..............if makes sense.

I would learn the light and how much it uses, so for example a typical day or night use maybe 30m total. Measure the voltage(variable on what levels used). Then if its just 4v, you could top off every other day or every third day if usage is similar. You may find you use it once a week, the voltage after hour 2hr hike maybe 3.5v, so topping off for next week's hike makes sense.

Some of my cells(work especially) get topped off every day, voltage is usually around mid 3's , little use it maybe 4v. Still get topped off for next days use, as it maybe used for 4-5 hrs solid(again a variable). So i prefer to be prepared(piece of mind) than to be caught short(have spare cells and lights anyway, just the way i am). Ideally a couple of cells for a light, swap out , charge used one and simply rotate the two cells with use. Everyone has their own little practices that suit their applications, some work , some wont depending on use.

IMHO its just not worth all the faffing about for a cell, typical cost these days is $5-$10. Even used daily your going to get a few years use. By then, a better cell(by that, maybe higher rating or mah) will be available. imo anyway.

Enjoy!

ven said:

I prefer to charge outside the light, however the built in USB can come in handy for when out and about(car for example). There is no memory with the cell, so use, top up, repeat. Would not worry too much on using 20% to 80%, kind of kills actual enjoyment and too much faffing around to get a few more cycles of life on a $6 cell. Usually cells can be 300-500 cycle life(think to 70% capacity iirc...........)Any way, topping up from say 3.6v is not a full charge cycle, so in effect you could end up topping off 600-1000 times..............if makes sense.

I would learn the light and how much it uses, so for example a typical day or night use maybe 30m total. Measure the voltage(variable on what levels used). Then if its just 4v, you could top off every other day or every third day if usage is similar. You may find you use it once a week, the voltage after hour 2hr hike maybe 3.5v, so topping off for next week's hike makes sense.

Some of my cells(work especially) get topped off every day, voltage is usually around mid 3's , little use it maybe 4v. Still get topped off for next days use, as it maybe used for 4-5 hrs solid(again a variable). So i prefer to be prepared(piece of mind) than to be caught short(have spare cells and lights anyway, just the way i am). Ideally a couple of cells for a light, swap out , charge used one and simply rotate the two cells with use. Everyone has their own little practices that suit their applications, some work , some wont depending on use.

IMHO its just not worth all the faffing about for a cell, typical cost these days is $5-$10. Even used daily your going to get a few years use. By then, a better cell(by that, maybe higher rating or mah) will be available. imo anyway.

Enjoy!

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Thank you for your input Ven! So what brand of charger do you use? And also does it come with the one that can measure the actual voltage of the cell?

Most of my chargers have a V readout for ease, xtar vp1 , vp2 and vp4. I have the older xp4 and sp1 which do not have a readout, good as back up/over spill cells when others taken up. My most used is the opus bt c3100 v2.2, excellent charger for the money and seen me right for years. I do find it easier placing a cell in the bay and seeing the V readout, gives an idea of where i am up to and how much i am using. Soon with use, you build an idea up of the light, how much juice you use. Before you know it, your guessing the voltage down to a 0.1v .

With any new charger, i always do my check with a multi meter, get an idea of the termination voltage(near 4.2v). Also that the charger is terminating and not trickle charging..........once it shows charged. Basic stuff, but gives confidence in the equipment used(safety).

If you plan on just using a couple of lights, a dual bay charger would work fine, if plan on getting a few lights down the line(not sure how many you have), then a 4 bay charger might make a better investment long term.

For chargers start here: http://lygte-info.dk/info/roundCellChargerIndex UK.html
A significant part of the chargers on the market are in that list and can be compared.

^^^^^^^^^^ he da man

HKJ said:

For chargers start here: http://lygte-info.dk/info/roundCellChargerIndex UK.html
A significant part of the chargers on the market are in that list and can be compared.

Click to expand...

Wow this is an awesome link! Thank you

ven said:

Most of my chargers have a V readout for ease, xtar vp1 , vp2 and vp4. I have the older xp4 and sp1 which do not have a readout, good as back up/over spill cells when others taken up. My most used is the opus bt c3100 v2.2, excellent charger for the money and seen me right for years. I do find it easier placing a cell in the bay and seeing the V readout, gives an idea of where i am up to and how much i am using. Soon with use, you build an idea up of the light, how much juice you use. Before you know it, your guessing the voltage down to a 0.1v .

With any new charger, i always do my check with a multi meter, get an idea of the termination voltage(near 4.2v). Also that the charger is terminating and not trickle charging..........once it shows charged. Basic stuff, but gives confidence in the equipment used(safety).

If you plan on just using a couple of lights, a dual bay charger would work fine, if plan on getting a few lights down the line(not sure how many you have), then a 4 bay charger might make a better investment long term.

Click to expand...

I see. But why choose termination rather than trickle?

soulzaeb said:

I see. But why choose termination rather than trickle?

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I need the charger to terminate at the correct voltage, so for example, with the cell you use, i want it to terminate at 4.2v(or a little bellow). If the charger does not terminate, and carry on charging(or trickle charging), the voltage increases and can become a safety issue. Its best practice not to leave any cells charging unsupervised, if this did happen and the charger carried on............the risk of a fire increases and it will shorten the cell life if done regular. So for piece of mind, i need to know i can depend on my equipment, safety first, but also looking after my cells long term.

ven said:

I need the charger to terminate at the correct voltage, so for example, with the cell you use, i want it to terminate at 4.2v(or a little bellow). If the charger does not terminate, and carry on charging(or trickle charging), the voltage increases and can become a safety issue. Its best practice not to leave any cells charging unsupervised, if this did happen and the charger carried on............the risk of a fire increases and it will shorten the cell life if done regular. So for piece of mind, i need to know i can depend on my equipment, safety first, but also looking after my cells long term.

Click to expand...

Ok. I see what you mean now. Thank you so much ven ^^

Can't say too much more than has been said other than shorter charge cycles do tend to wear batteries out a little quicker but charge cycles are primarily based on the 100% of capacity charged = a full cycle such that 5 cycles of 20% each charging is about the same as 1 cycle charging 100%. It is however the final 10% of the charge cycle that does the most "harm" to a battery in that it where most of the heat in charging that weakens batteries over time is generated so in that respect it is better to try and discharge mostly to 50% or more and recharge than 80% or less but in reality unless you are daily recharging batteries and discharging them quickly in heavy use getting only 300 cycles instead of 600 means it still may only save you $1 or less a year in battery costs by better battery use and charging practices. IMO find what is most convenient to you and if you find yourself too often being too inconvenienced by dead batteries in use either buy another battery or adjust your usage/charging practices.

Lynx_Arc said:

Can't say too much more than has been said other than shorter charge cycles do tend to wear batteries out a little quicker but charge cycles are primarily based on the 100% of capacity charged = a full cycle such that 5 cycles of 20% each charging is about the same as 1 cycle charging 100%. It is however the final 10% of the charge cycle that does the most "harm" to a battery in that it where most of the heat in charging that weakens batteries over time is generated so in that respect it is better to try and discharge mostly to 50% or more and recharge than 80% or less but in reality unless you are daily recharging batteries and discharging them quickly in heavy use getting only 300 cycles instead of 600 means it still may only save you $1 or less a year in battery costs by better battery use and charging practices. IMO find what is most convenient to you and if you find yourself too often being too inconvenienced by dead batteries in use either buy another battery or adjust your usage/charging practices.

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Oh this is nice to know. But yea good point, that I should just buy a new battery if the one I'm using worns out. Thank you for the input ^^

soulzaeb said:

[...] Reason is because I read somewhere that the rechargeable battery cells have limited "charging cycles" (lets say 1000 charge cycles for a brand new one). So what happens is, when you charge it to full every time, the charge cycle number lessens. Thus, this method of charging it when it is 60% then only up to 80% therefore "prolongs" the charge cycles for the particular cell. [...]

Click to expand...

The normal cycle lifetime ratings is in terms of 100% cycles, i.e. using full capacity. If you use less then you need to normalize your cycle comparisons, e.g. if you use only half the capacity on each cyle then 2 half-cycles = 1 full cycle when accounting for total Ah delivered by the cell. When we compare lifetime we normally compare this total (cumulative) Ah delivered by the cell.

Studies have shown that if you use smaller cycles, and keep them centered around 50% SOC, then you can prolong the lifetime (cumulative Ah), because this keeps the cell out of extreme conditions that accelerate degradation processes. But you may have to tradeoff convenience for this extra life, since now you must manage the (dis)charge range, which can be cumbersome if done manually.

I'll just ad that I've charged my xt12gt both externally and using the magnetic USB charger and found the USB charger does an excellent job, unlike Armytek's magnetic charger. So, I'd use whichever method is most convenient for you. The Klarus is the only light I have that I don't charge externally. It's magnetic charger is both fast and tops off the battery just as well as my external chargers do, based on using the external charger/tester to verify the batteries charge level. I keep the light by the door, and use it almost nightly for various nighttime activities. I charge it whenever the battery indicator turns red, which is usually about a couple times per month. It doesn't appear to lose significant output running it in orange, but that's just based on what I can tell by eye. I haven't taken any measurements to see how much battery it needs to hit turbo, but it seems to be able to still hit it all the way through orange from what I can tell, so I don't top it off.

Since "flashlights" weren't mentioned in the thread title, I'll give a more general answer since I actually don't have single Li-Ion cells, only NiCd and NiMh. I do have Li-Ion battery packs for some devices, however...

Since "cells" were in the thread title, I only will list those devices who have replaceable cells, not battery packs or built-in batteries...

My portable cassette player is powered by 2 Eneloops which get charged every weekend for safety (so they never run out) unless it was a week off from work or a "broken" week where the total of workdays of this and the next work week won't exceed 5. They currently get charged using a HAMA dumb charger, but I consider if I should switch to a Tronic charger I still have. Advantage would be automatic shut-off when full, disadvantage would be more stress by a much higher charge current (up to 2A instead of 0.12-0.2 A) and a bit of discharging before the charge begins.
The cells of my electric toothbrush (actually a battery toothbrush designed for Alkalines, but powered by rechargeables) gets charged twice a month. I'll move around the date a bit if I'm off work for a considerable part of the month because on free days I brush my teeth more often. I'm currently using the same HAMA charger here.
The 6 D cells of my boombox also get charged about twice a month, and I'm actually considering syncing it up with the toothbrush. For charging, I put them into the battery case of another old boombox which is wired up to the power supply of my old Atari 2600 game console, which puts out about 500 mA.
The batteries of my wireless microphone get charged if a day before a show, I check them and they don't read "full" anymore, or if it's a long gig, they get charged no matter what (unless they didn't get used after the last charge). I also use the HAMA charger here.
The batteries of my musical keyboard follow a similar routine, but since they are 6, I'm using the Tronic charger here which has got 6 bays.
The batteries of the portable cassette player I use to digitize cassette recordings into the PC get charged about once a year at an event called "Charging of non-used batteries", using either the HAMA or the Tronic charger.
The batteries of my RC forklift (one 9V and 4 AAA's) get charged as needed if I realize that they are already lacking a proper charge, using the HAMA charger.
The batteries of my soap dispenser get charged every year at the switchover to daylight savings time (late March)... also using the HAMA charger.
The batteries in my wall clocks get charged when they die, but that's because I haven't developed a better rhythm for those yet. I'll also use the HAMA charger there.
The other 9V's get charged when they die as well, using the HAMA charger (those are in my bathroom scale and a multimeter).
The remaining batteries which aren't currently in service all get charged at the yearly event "Charing of non-used batteries" using either the HAMA or the Tronic charger which are both active in this event. However, some of the LSD ones might not get recharged if I check them and they are still sufficiently charged.

Most of the time I charge my cells (AA and AAA NiMH) before I use them. Peak usage is during holidays when my wife pulls out the LED holiday candles. During this time period I'll keep a few sets charged to swap into the candles when they get dim. When the candles get put away, the batteries come out and I put them in their cases in whatever state of charge they're at. During off peak, where the cells aren't used as much, I rotate them into the devices I do use (audio recorders, weather station, flashlights). I'll charge a set, swap them in, and store the discharged ones... I generally store my cells not fully charged especially during off-peak times.

I've always used my EBL-999 for charging duties, but I did get a couple Maha MT-C9000s recently. I'll use those for periodic refresh and breakin cycles on the cells, or to test cells that are suspected to be weak or high-resistance. I'm currently breaking in all my AAAs and labeling them with their mAh capacity, and am storing them sorted by measured capacity so I can match them better in devices that use more than one cell, and putting bad ones (high resistance or abnormally low capacity) into the recycle pile.

Chad Varnadore said:

I'll just ad that I've charged my xt12gt both externally and using the magnetic USB charger and found the USB charger does an excellent job, unlike Armytek's magnetic charger. So, I'd use whichever method is most convenient for you. The Klarus is the only light I have that I don't charge externally. It's magnetic charger is both fast and tops off the battery just as well as my external chargers do, based on using the external charger/tester to verify the batteries charge level. I keep the light by the door, and use it almost nightly for various nighttime activities. I charge it whenever the battery indicator turns red, which is usually about a couple times per month. It doesn't appear to lose significant output running it in orange, but that's just based on what I can tell by eye. I haven't taken any measurements to see how much battery it needs to hit turbo, but it seems to be able to still hit it all the way through orange from what I can tell, so I don't top it off.

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Thank you for sharing this, I was about to charge mine from playing all night last night, but it is still green, perhaps when it turns orange then I'll charge c=

If you have a Harbor Freight nearby, you can pick up a multimeter for about $6 (I once got one free with coupon while buying some other small item). Then you can measure your cell's voltage any time you like.