Questions about 18650 batteries, charging and buying

Hello, first of all thank you for this great community and i lot great posts. However since i'm new to this area (rechargeable batteries) i need some help with a new flash light that has turned up since it's with a new type of batteries which are 18650. Now i tried searching a lot of places, even here for answers, but i could not find any. I will try to explain my situation the best i can and i hope someone has and answer and a way for me to learn more about this type of new batteries (new to me of course not, new as it just came out).
A couple of weeks i bought a flashlight Cree XML-T6 (Picture of how the box that comes in looks), witch came with a new type of batteries for me which are 18650 type. Since this is a new type of batteries for me i need some help with them, and some questions regarding their charging, buying advice, general info on using them, and some other questions which i hope i can get info here. Now i'm providing 2 picture about the type of batteries that the flashlight came with, they are as follow 2x Ultrafire NK 18650 6800 mAh, 4.2V Li-ion (Picture 1, Picture 2. When checked with multi meter one of the batteries is shown to be 0.32 v of charge while the other one is 3.85 v change.

Now before i start with the questions i want to tell you that i have a proper charger and that is Opus BT-C3100 V2.2, which from what i know will be able to charge 18650.

Now regarding the questions. I will be asking them with as much as information as i can give you so you can help me.

1. Which batteries should i buy is there a brand that is better, and also which would you recommend?
2. What Volts should i be buying?
3. What mAh, should i be looking for when buying?
4. I know that i should be getting protected batteries, but does that matter when i have a smart charger?
5. My flashlight came without any info on what type of batteries is using, but i'm asking is there a difference and will my flashlight work with low V batteries?
6. So this flashlight that i bought is mostly for emergency cases or when i need to search for something and is standing on next to the bed, my question is what should i be worried regarding the batteries?
7. Since those batteries are rechargeable, how many charge cycles would they get and on what time period should i be charging them?
8. What is the best advice's you can give me about using those type of batteries.

Now about the batteries right now i'm looking at KeepPower 18650 @ 2600 mAh, or KeepPower 18650 @ 3500 mAh, are these good, they are sold as a pack of 2.

Now i know i may have missed some steps or even not wrote what you may need to help me, but for now that is and i hope anything else you can write me and i can add.

MaestroDaVinci said:

1. Which batteries should i buy is there a brand that is better, and also which would you recommend?
2. What Volts should i be buying?
3. What mAh, should i be looking for when buying?
4. I know that i should be getting protected batteries, but does that matter when i have a smart charger?
5. My flashlight came without any info on what type of batteries is using, but i'm asking is there a difference and will my flashlight work with low V batteries?
6. So this flashlight that i bought is mostly for emergency cases or when i need to search for something and is standing on next to the bed, my question is what should i be worried regarding the batteries?
7. Since those batteries are rechargeable, how many charge cycles would they get and on what time period should i be charging them?
8. What is the best advice's you can give me about using those type of batteries.

Now about the batteries right now i'm looking at KeepPower 18650 @ 2600 mAh, or KeepPower 18650 @ 3500 mAh, are these good, they are sold as a pack of 2.

Now i know i may have missed some steps or even not wrote what you may need to help me, but for now that is and i hope anything else you can write me and i can add.

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1. Stay away from ultrafire, "whatever"-fire, and anything advertising more than 3600mah as that's the top on real 18650s. Buy Keeppower, Orbtronics, Nitecore, Olight, or other major brands for protected batteries. At this point I'd tell you to not enter the unprotected battery space as you don't need it for that light. But there is lots to read on this site if needed.

2. 18650 will be 3.6 or 3.7V nominal rating. Operating range is 2.8 or 3.0V up to 4.2V. If a battery gets above or below this range it is absolutely dangerous to use and charge; toss it. The one battery you have should be tossed due to the low V. The other should be tossed because it is overstated capacity and questionable quality on those grounds. Remember... the Samsung Galaxy Note fires, hover board fires, and e-cigarette explosions you've read of all trace back to this type of battery. Also, in lights that need 2 batteries, they have to be exactly the same. Same V, same age, etc. Buy two together and keep them forever married. Use together, charge together, keep together.

3. There are various capacities, depends what you want to spend. 2600mah is pretty cheap, but 3400mah will give lots more output for not that much more.

4. Protected means it has a circuit that will stop the flow if voltage gets too low. This protects the battery, but recharge promptly. Best to avoid hitting that. It also prevents too fast of discharge, in a way, but you won't be taxing thst with a single xml led (or LatticeBright that may actually be in your light). The charger won't care protected or not. Charge at 1A or below, generally, to maximize battery life.

5. Some lights have low voltage protection, while others have drivers (electronics) that won't work outside specific ranges. I'm not going to study your light, so I'd tell you it is about the batteries and keeping them in the right range.

6. The above covers it generally. The charger you have is a great one as it tells you V and can do mah testing.

7. After 500 full cycles they will have lost 20% or so of the capacity. Running them all the way down hurts more. Topping them off constantly also hurts a little. There's no real expiration date, but after a few years you might want to replace or at least test.

These are the basics. If this is a gateway light and you start hungering for even higher power lights, then there will be more to learn. For now... protected Keeppower batteries will serve you well. Toss the batteries you got with it immediately, don't even try to use or charge them.

^^^^^excellent post^^^^^

:welcome:

Good thing today, decent chargers and cells are not expensive, no reason at all for anyone to run cheap fire cells. Like filling your fuel tank 1/6th full and expecting to get full tank mileage.

For a good all round cell, sany/pany GA's are a 10a 3500mah which pretty much covers 95% of lights performance wise.

Bdm82 said:

3. There are various capacities, depends what you want to spend. 2600mah is pretty cheap, but 3400mah will give lots more output for not that much more.

These are the basics. If this is a gateway light and you start hungering for even higher power lights, then there will be more to learn. For now... protected Keeppower batteries will serve you well. Toss the batteries you got with it immediately, don't even try to use or charge them.

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Thank you for all of the stuff in the post.
3. But here is my problem right now i can buy only KeepPower 18650 @ 2600 mAh for around 19 USD, which is the only ones that they have in stock (i'm using local retailer from my country), or the KeepPower 18650 @ 3500 mAh are around 27 USD and here how they look: KeepPower 18650 @ 2600 mAh; KeepPower 18650 @ 3500 mAh (out of stock). My main question regarding these batteries is are they good enough?

As for the gateway light, well this was bought because most of flashlight that are out on the market here are either too expansive (somewhere between 85 USD and 125 USD) which i don't need, or too cheap (around 5-25 USD) and very bad quality. As i mentioned before i bought that flashlight only to be able to use in emergency when the power is out or if i need to look for something in the dark and will be staying next the the bed. So for me a higher brand or price for a flashlight is out of the question since it wont be used that often.

KeepPower are very good, iirc the 2600mah are sanyo inside, the 3500mah are the GA inside. If you dont plan on long uses, the 2600mah will suffice.

Your prices are crazy high, WOW ................that is painful!

For good value lights, check convoy brand out, have a look at aliexpress(simon/convoy store). Quite a few options with different outputs and colour temps to choose from. $20 ish and under generally.................

ven said:

^^^^^excellent post^^^^^

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Thanks ven! Haha, I debated replying figuring you'd get to it as the CPF resident battery expert.

MaestroDaVinci said:

Thank you for all of the stuff in the post.
3. But here is my problem right now i can buy only KeepPower 18650 @ 2600 mAh for around 19 USD, which is the only ones that they have in stock (i'm using local retailer from my country), or the KeepPower 18650 @ 3500 mAh are around 27 USD and here how they look: KeepPower 18650 @ 2600 mAh; KeepPower 18650 @ 3500 mAh (out of stock). My main question regarding these batteries is are they good enough?

As for the gateway light, well this was bought because most of flashlight that are out on the market here are either too expansive (somewhere between 85 USD and 125 USD) which i don't need, or too cheap (around 5-25 USD) and very bad quality. As i mentioned before i bought that flashlight only to be able to use in emergency when the power is out or if i need to look for something in the dark and will be staying next the the bed. So for me a higher brand or price for a flashlight is out of the question since it wont be used that often.

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Ouch; that's about double what I'm used to. What country are you in?
But yes, these are absolutely good enough.

Would not go that far, but thanks

I would at those cell prices.............

Bdm82 said:

Ouch; that's about double what I'm used to. What country are you in?
But yes, these are absolutely good enough.

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I live in Bulgaria, and here we don't really get a lot of good battery shops in any case online or offline, and since we don't have access to Amazon (i mean good prized one) we get those kind of prizes.

Since Bulgaria is in EU you can just buy from Nkon, they have good quality cells at good prices.

Try getting your cells from a source such as NKON (google it, you'll find them). Much better prices and they only sell quality cells, have good stock, and a good variety. EG €5.25 for the Keeppower protected 2600mAh.

Edit: Oh, only just saw the post above mine after posting this. So, just reiterating the same thing.

Trango said:

Since Bulgaria is in EU you can just buy from Nkon, they have good quality cells at good prices.

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samgab said:

Try getting your cells from a source such as NKON (google it, you'll find them). Much better prices and they only sell quality cells, have good stock, and a good variety. EG €5.25 for the Keeppower protected 2600mAh.

Edit: Oh, only just saw the post above mine after posting this. So, just reiterating the same thing.

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Thank you both, i will check out the store.

Ooh yeah, f@king reality of prices in Bulgaria for everything is just so. Anyway, I'll try to help you with batteries and flashlights as far as I can, because I've learned a lot here in this forum and you'll be glad I'm a little useful to someone. I am from Bulgaria too. Currently the only place from which you can order batteries at a good price is nkon.nl. I ordered from there many times and am always pleased remains. Very fast shipping and honest attitude. There are other shops in the UK, and Germany that sell batteries, but between the UK almost nobody wants to send to Bulgaria and from German stores supply is too high and battery prices too. For this I recommend nkon. For me they are probably the best shop for batteries and flashlights in the EU.
You say you're looking for what is available in local shops, but apparently not enough. There is a large supply of batteries and flashlights, but not all are good prices. Local dealer of Olight (olight.bg) offers good prices for all products of the brand. Slide Bulgarian knives forums, they have many topics for batteries, flashlights and others, a lot of members are also in this forum too, such as me, FlashLion ........ and many others.
Ven already has directed what to look for better budgetary flashlight - Convoy.
If you have other questions to me, just send me a PM, because my English is not good.

MaestroDaVinci said:

KeepPower 18650 @ 3500 mAh, are these good, they are sold as a pack of 2.

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Yes, they are good.
If you buy and use these then you will be pleased with how they work, I don't think the Ultrafire batteries will be nearly so pleasing to use.

I just got a package from the USA today from Illumn.com, 14 Li-Ion cells including 4 x KeepPower 18650 @ 3500mAh protected button top cells, I'm looking forward to charging these up and turning the stored power into lumens.

MaestroDaVinci said:

4. I know that i should be getting protected batteries, but does that matter when i have a smart charger?

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Probably fine with non-protected, but safer with protected. Sometimes something goes wrong and Li-Ion battery can be dangerous. Charging with a smart charger should be safe but draining with a flashlight that sits idle for to long could result in the battery voltage dropping too low, better to have protection that will cut out if the voltage drops too low.

MaestroDaVinci said:

7. Since those batteries are rechargeable, how many charge cycles would they get and on what time period should i be charging them?

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Hundreds, I wouldn't even worry about that. Good batteries like the KeepPower ones should be fine for several years.
I've got some eight year old Li-Ion cells that seem to be still working OK.

dellman666 said:

Ooh yeah, f@king reality of prices in Bulgaria for everything is just so. Anyway, I'll try to help you with batteries and flashlights as far as I can, because I've learned a lot here in this forum and you'll be glad I'm a little useful to someone. I am from Bulgaria too. Currently the only place from which you can order batteries at a good price is nkon.nl. I ordered from there many times and am always pleased remains. Very fast shipping and honest attitude. There are other shops in the UK, and Germany that sell batteries, but between the UK almost nobody wants to send to Bulgaria and from German stores supply is too high and battery prices too. For this I recommend nkon. For me they are probably the best shop for batteries and flashlights in the EU. You say you're looking for what is available in local shops, but apparently not enough. There is a large supply of batteries and flashlights, but not all are good prices. Local dealer of Olight (olight.bg) offers good prices for all products of the brand. Slide Bulgarian knives forums, they have many topics for batteries, flashlights and others, a lot of members are also in this forum too, such as me, FlashLion ........ and many others. Ven already has directed what to look for better budgetary flashlight - Convoy. If you have other questions to me, just send me a PM, because my English is not good.

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Thank you for the info i will check it out.

KiwiMark said:

Yes, they are good. If you buy and use these then you will be pleased with how they work, I don't think the Ultrafire batteries will be nearly so pleasing to use. I just got a package from the USA today from Illumn.com, 14 Li-Ion cells including 4 x KeepPower 18650 @ 3500mAh protected button top cells, I'm looking forward to charging these up and turning the stored power into lumens. Probably fine with non-protected, but safer with protected. Sometimes something goes wrong and Li-Ion battery can be dangerous. Charging with a smart charger should be safe but draining with a flashlight that sits idle for to long could result in the battery voltage dropping too low, better to have protection that will cut out if the voltage drops too low. Hundreds, I wouldn't even worry about that. Good batteries like the KeepPower ones should be fine for several years. I've got some eight year old Li-Ion cells that seem to be still working OK.

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Thank you. But for now i ordered KeepPower 18650 @ 2600 mAh.