Hi all, I need some education here. I just found out about 16650 lithium ion batteries and ordered a couple for my Surefire flashlights—love not having to use cr123s. I have a Nitecore D4 charger that I've been using with my nimh and other 18650 lithium ions and has worked great but it doesn't say it is ok for 16650 batteries on their website but other chargers on their website like the new i2 and i4 say they are good for them. It is the same voltage as 18650's right? Wouldn't it be ok for 16650s as well?
Charging 16650 or any lithium ion batteries for that matter
- Thread starter heckeng
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parametrek
Enlightened
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Yes it will work fine. As long as it is a normal 3.6V or 3.7V li-ion you can use the same charger. (If it is a 3.2V LiFePO4 then that needs a special charger but I doubt you have that type of battery.)
archimedes
Flashaholic
... thread moved to Electronics / Batteries ...
ChrisGarrett
Flashlight Enthusiast
Here's the deal...unless you're buying no-name generic Chi-Com 16650s, the good ones that we have access to are made by Sanyo--UR16650 either v.1, or v.2.. The difference between the two is that v.1 is actually a 4.30v ~2100mAh cell and v.2 is a 4.35v 2500mAh cell.
Since a lot of these have protection circuits thrown in, they become a 17670 due to added width of the metal strip and length add by the PCB. 17=17mm W, 67=67mm L and 0= is a cylindrical cell.
Here's the second caveat: since there's a protection circuit added, one can't charge the cells up to either 4.30v, or 4.35v, since that's something a protection circuit does--it's a feature, so you won't be filling them up to their max capacity.
Another issue is finding a charger to charge 4.35v cells up to 4.35v and your NC D4 doesn't do that.
If you're running protected 16650s, then any capable li-ion charger will charge them up to 4.20v, but since SF lights are designed 'mostly' around 6.0v (2xCR123As), you might want as much voltage as you can get, unless you've replaced the P60 drop-in with some geared for 4.20v. So you would probably want the naked cells, something like a smaller Liitokala Lii 100s or 202 charger, which charges up almost anything we can throw at it.
Protected 16650s vs. naked 16650s?
4.20v, protection and slightly less capacity vs. 4.35v, naked/no protection circuit, ~2500mAh capacity?
You can get by without button tops because the P60 has a spring.
Just some things to consider.
ETA:
I have added a Redilast 4.20v P60 3 mode XM-L2 to my 6P and bought two of the Redilast 17670s that are v.1 Sanyos 4.30 ~2100mAh cells. I can only charge them up to 4.20v, due to the fact that they have PCB added.
Still, since I never use the light, they're fine.
Chris
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That's only true if the rewrapper chose to use a protection circuit configured for lower 4.20V cells. But most modern protection circuits can be configured at variable overvoltage protection values (including higher values for 4.30V and 4.35V cells). So you'll be able to charge them fully as long as the rewrapper configured them with the appropriate protection circuit.
Thank you guys, that is exactly the information I was looking for. They are the 2500 MAH batteries so I assume they are supposed to be up to 4.35 V. I believe the digital Nightcore charger only goes to 4.2 V which makes sense of why it was not officially approved for the 16650 batteries. The I2 Charger is good for 4.35 V batteries which again makes sense. Since the Surefire G2X pros are regulated, I would assume that as long is the voltage that they want is under the 4.2 V that the 16650s should work fine in them. Or do you know if the Surefire actually do want closer to the full 6 V from the two CR123's.?
ChrisGarrett
Flashlight Enthusiast
You just have to see if a 4.20v/4.35v cells will fire up your G2X Pros and what, if any, output you might be losing.
We're not talking much difference between 4.20v and 4.35v, on the voltage side of things and we're not talking much capacity loss, ~2300mAh vs. ~2500mAh, but there are some numbers you can expect to deal with.
As per Gauss' comment, I'm no 'protected 16650 expert,' but at more than a few of the common battery sites, they'll put a disclaimer in that 4.20v will be about the best you can expect, so they're NOT using specially configured PCBs for 4.35v cells. They're just grabbing one off of the shelf and going to town, since they're not selling thousands of these at a stretch and a lot of flashlight people, (especially SF people who would more commonly be using the 16650/17670 cells in the first place,) aren't battery geeks.
Here's an example:
https://www.illumn.com/batteries-ch...ah-sanyo-ur16650zta-protected-button-top.html
Anyhow...
Chris
That's not surprising. it's probably simpler / cheaper to use the ubiquitous 4.20V PCBs on all their cells.
On the linked ILLUMN page they write "Please Note: The internal cell is capable of being charged to 4.35V, but the protection circuit is set to 4.20V, we did not notice a huge capacity difference with this." According to HKJ's review of that Sanyo UR16650ZTA you gain over 15% capacity by charging it to 4.35V vs 4.20V. That's not "huge" but may be significant in some applications.
If you have a charger with configurable charge target voltage then you can probably charge them higher than 4.20V since the overvoltage protection for 4.20V is probably set to trip at around 4.29V. But if you push it too close to the trip voltage then you risk inadvertent trips - resulting in premature charge termination.
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ChrisGarrett
Flashlight Enthusiast
I have the Liitokala 100s and 202s and I think the latter, as a rule, charges 3.6v/3.7v cells up to 4.22-4.23v, both of them as a rule.
I don't worry too much about it, since the light is little used and I would generally run naked cells.
For cops on the beat, using SF lights and whose departments don't provide CR123As gratis, running the UR16650ZTAs at 4.35v might just be the best option, even with no protection circuit.
Chris
ven
Flashaholic
I charge my keeppower 16650's at either 0.5a or 1a, simply down to time allowing in work. If i have a few hours, i do a slower rate, if a little rushed i use the 1a(both rates are fine to use).<br>
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I have swapped most of my naked sanyo 16650 cells(4.35v charged on the 3.8v setting on xtar vp2) to KP ones . Charging them to 4.2v in my real world uses ,makes no difference to me, very rare i see bellow 3.7v in between charging. My works keeppowers are a little longer due to the PCB which actually works better for me. I use them in surefire lights in work, the extra few mm makes contact better with some p60's. As said, these are charged to 4.2v as the PCB would trip if tried to charge to 4.35v(sure i have by mistake, and off the top of my head.................talking a while back, it would not charge past 4.25 or 4.2? voltage. Not had one trip yet anyway. Even some high drops!. Might have just caught it early. <br>
I do have the option to charge to 4.35v in work on my bc100, but it is not the most user friendly and time saving way(press hold type UI to access then click to set level). Home, vp2 and btc3100 v2.2 with the switch under the charger body(inside) which again is not really convenient either. <br>
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I have a couple of bored surefire lights, these are not work lights though, my work are all standard body and admit to wanting/liking the original strength. 16650 cells have really helped me out and enjoy my surefires, 2500mah and maybe 5a or so they are good for. Granted i cant get the full potential out of some drop ins, but i swap about to suit the standard body/16650 fuel better. Besides that, i dont need 2000+ lumens in work other than for grins and giggles. Most my work p60's ask is around 3a, most get used at a lot less...................150-200lm seems about perfect generally in work.<br>
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On using 16650 with the surefire incand, i have not compared directly and no doubt 2x cr123 will push a few more lumens, but 16650 drive an impressive beam still for sure........................guilt free lumens as well.
<br>
I have swapped most of my naked sanyo 16650 cells(4.35v charged on the 3.8v setting on xtar vp2) to KP ones . Charging them to 4.2v in my real world uses ,makes no difference to me, very rare i see bellow 3.7v in between charging. My works keeppowers are a little longer due to the PCB which actually works better for me. I use them in surefire lights in work, the extra few mm makes contact better with some p60's. As said, these are charged to 4.2v as the PCB would trip if tried to charge to 4.35v(sure i have by mistake, and off the top of my head.................talking a while back, it would not charge past 4.25 or 4.2? voltage. Not had one trip yet anyway. Even some high drops!. Might have just caught it early. <br>
I do have the option to charge to 4.35v in work on my bc100, but it is not the most user friendly and time saving way(press hold type UI to access then click to set level). Home, vp2 and btc3100 v2.2 with the switch under the charger body(inside) which again is not really convenient either. <br>
<br>
I have a couple of bored surefire lights, these are not work lights though, my work are all standard body and admit to wanting/liking the original strength. 16650 cells have really helped me out and enjoy my surefires, 2500mah and maybe 5a or so they are good for. Granted i cant get the full potential out of some drop ins, but i swap about to suit the standard body/16650 fuel better. Besides that, i dont need 2000+ lumens in work other than for grins and giggles. Most my work p60's ask is around 3a, most get used at a lot less...................150-200lm seems about perfect generally in work.<br>
<br>
On using 16650 with the surefire incand, i have not compared directly and no doubt 2x cr123 will push a few more lumens, but 16650 drive an impressive beam still for sure........................guilt free lumens as well.
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KentuckyMike
Enlightened
While Malkoff and Illumn both use the same disclaimer about the protection circuit being set to 4.2V, Keeppower's own site says the protection circuit is set to 4.35V. This was NOT always the case, but the change to the text came sometime over the last year or so. Two snippets of note are "4.35 volts max voltage and 3.7 volts nominal voltage" and "To get the full capacity from the battery it must be charged with a 4.35 volt charger."[1]
Having said that, Chris is definitely right about the protection circuits. These aren't exactly high precision things. I have a fresh 16650 from Craig at Illumn that consistently cuts off at about 4.29 and another that cuts off at 4.31 when put on a 4.35V charger that usually charges unprotected cells right to 4.35V on my DMM. Older 2550mAh 16650s from Keeppower cut off between 4.19 and 4.21V on the same charger (and they did when new—last year—as well). This seems to indicate they have updated the protection circuit, but also that it still isn't accurate nor precise. Bottom line, I don't make a habit of using the 4.35V setting on protected cells regardless of Keeppower's claims, as I'd rather not rely on the cell's circuit to stop charging on a regular basis. Unprotected Sanyos, on the other hand, I charge to 4.35V every time. If you have protected cells and you want to use a 4.35V charger, you may want to be sure the cell's protection circuit isn't cutting the charge before you make this a long term practice—especially since there may well be cells with both 4.2V and 4.3/4.35V circuits still floating around the supply chain.
Like Chris, Craig, and Gene all say...the difference between 4.2V and 4.35V will be negligible in actual usage in most lights, and it really isn't worth sweating either way. I don't notice any difference in my usage between protected cells on a 4.2V setting or unprotected ones at a 4.35V setting.
[1] "KeepPower 16650 2500mAh protected lithium rechargeable battery P1665J 3.7V." KeepPower Technology. Accessed August 24, 2018. http://www.keeppower.com.cn/products_detail.php?id=335
Without actual tests I wouldn't rely on that text implying that they actually do use a circuit properly configured for 4.35V cells.
I don't see any such discussion above. Typically OVP can be set in 5mV increments, with accuracy +/-25mV, and it employs a delay time, typically 1.2s, but configurable between 0.15s and 4.6s (e.g. for the ubiquitous Seiko S-8261). So what you observed is within spec.
This is strange. 4.20V cells normally have OVP set closer to 4.29V than 4.20V. It seems you encountered conditions where OVP tripped at unusually low values (4.20V). But that has nothing to do with OVP values for 4.35V cells.
Not true. As I remarked above, HKJ's tests show 15% more capacity for a full cycle, which will constitute a higher percentage of usable capacity if you use only a portion of full capacity (e.g. till high mode kicks off). It may even be a "huge" difference in some devices (despite ILLUMNs inaccurate claims to the contrary). If the improvement was "negligible" there would be little reason to introduce 4.35V cells.
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KentuckyMike
Enlightened
Interesting. So my experience is untrue. I'm glad you were able to clarify that for me. I was merely stating that in my experience, I have not experienced a noticeable difference in realtime usage. Your experience my be different, but you have yet to counter with real world experience. I respect HKJ's tests, but in my experience the difference has been negligible in the real world.
Also interesting that difference may be "huge" in your words today, when yesterday you wrote, "According to HKJ's review of that Sanyo UR16650ZTA you gain over 15% capacity by charging it to 4.35V vs 4.20V. That's not "huge" but may be significant in some applications."
I just wanted to share my experiences and my actual numbers. You, the OP, and everyone else are free to do with them what you will...including ignore them!
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The older remark applies to full discharges, but the remark above concerns partial discharges. The point is that if you effectively reduce capacity by doing partial (vs. complete) discharges, then the capacity between 4.20 and 4.35V becomes a larger percentage of that reduced capacity (possibly "huge" for some devices and usage patterns).
Oh Good Heavens this quibbling from someone who has made an unsubstantiated claim to have trained others online for so many years is quite unbecoming and another ding on credibility. By writing "Not true." about someone's own experience, You have made another impolite dismissal of one our members here. Perhaps rereading the forum rules would be in order sir; one opinion.
ven
Flashaholic
:grouphug:
GMUGNIER
Newly Enlightened
So - is there any definitive information to indicate if the new pcb is programed to allow consistent charging to 4.35v or is this still pie in the sky - hit or miss?
ChrisGarrett
Flashlight Enthusiast
Just assume that it'll be a 4.20v setting and if you get one and you can hit 4.30v-4.35v, then you're lucky.
Or...you just buy a naked cell and a 4.35v charger and just check things every once in a while.
Chris
GMUGNIER
Newly Enlightened
This may be helpful to some..
https://batteryuniversity.com/index...prolong_lithium_based_batteries/subscribe_thx
The main component that interested me was:
Table 4: Discharge cycles and capacity as a function of charge voltage limit.
Every 0.10V drop below 4.20V/cell doubles the cycle but holds less capacity. Raising the voltage above 4.20V/cell would shorten the life. The readings reflect regular Li-ion charging to 4.20V/cell.
Guideline: Every 70mV drop in charge voltage lowers the usable capacity by about 10%.
Note: Partial charging negates the benefit of Li-ion in terms of high specific energy.
Seems as though no matter what the application or desired result is - there are pro's and con's at the limits
https://batteryuniversity.com/index...prolong_lithium_based_batteries/subscribe_thx
The main component that interested me was:
Table 4: Discharge cycles and capacity as a function of charge voltage limit.
Every 0.10V drop below 4.20V/cell doubles the cycle but holds less capacity. Raising the voltage above 4.20V/cell would shorten the life. The readings reflect regular Li-ion charging to 4.20V/cell.
Guideline: Every 70mV drop in charge voltage lowers the usable capacity by about 10%.
Note: Partial charging negates the benefit of Li-ion in terms of high specific energy.
Seems as though no matter what the application or desired result is - there are pro's and con's at the limits
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^^^ It is generally true that increasing the charge termination voltage greatly increases degradation. But you should not trust those numbers since there is no link to any scientific evidence supporting them (a major problem with most of the claims on Battery "University" - which is why the site is blacklisted by Wikipedia). Generally the numbers will depend upon the specific Li-ion chemistry.
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