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The amount of current a battery can deliver isn't determined by what voltage it can be discharged down to which is a completely different attribute that batteries have... Each battery has a max recommended discharge rate which is called its "C Rating" and it is related to the total capacity of the battery itself... In this case the total battery capacity is 3400mah ... a 1 C rating ( if that is what it had ) would mean it could deliver 3400mah, in otherwords 3.4 amps of current. I was unable to find the discharge C rating on Panasonic's website but a 3rd party had tested it to be at 2.9a or just under 1C .
Rechargable batteries also have a charge C rating in addition to the discharge C rating...
My question may have been misstated or misunderstood. Each battery has its own discharge characteristics and two batteries with the same capacity can utilize it differently across their voltage range. Many batteries hit around 3.2 volts remaining charge and then drop like a rock. This one still has a fair amount of charge remaining at that point, but I'm not sure that it will be available to most of our mods, which will cut out before the battery. This leads me to believe that while the battery's capacity is in fact higher than others, its USABLE capacity in a mod may not be as much greater as it's total capacity would indicate. You can see its discharge properties here:
Test of Panasonic NCR18650B Protected 3400mAh (Green)
Test of Panasonic NCR18650B Protected 3400mAh (Green)
But since it's pretty much made for the EVIC they can change that dropout point in a firmware upgrade. Or it will just know when you put in 3400 for the battery.
I was responding more to danno's post than yours...
As you mentioned, with some of the protection seen in many PV's.... they won't be able to use the full capacity ( mah ) of the battery simply because they will cut off the power at 3-3.2 volts ( or so ).... The upside is that the same battery will live longer ( can be recharged more ) since it isn't being drained down to the lowest voltage the battery supports. The further you continually drain a battery to it's limits, the more you shorten it's potential lifespan.
Another thing that is hard on a battery and also shortens it's rechargeable lifespan is constantly using it at close to it's max C rating and drawing a lot of amps from it. This is one reason I was suprised that Joyetech is even recommending them for use in the Evic as apposed to using a high drain battery such as an IMR. I'll grant them that the Evic is limited on current, but not so much that they aren't pushing the higher mah batteries they are recommending up close to their recommended max C rating which in the long run will be detrimental to the potential lifespan of these batteries.
IMO... These are great batteries to use if you don't plan to use them at say... over 3.7v with a coil that doesn't go lower than 1.8 ohms... that would pull around 2a max and deliver up to almost 7.4 watts of power. If you plan to go past these numbers and draw more current... consider going with an IMR or other high drain battery instead so you can get the most life ( in recharge cycles ) out of your batteries.
As you mentioned, with some of the protection seen in many PV's.... they won't be able to use the full capacity ( mah ) of the battery simply because they will cut off the power at 3-3.2 volts ( or so ).... The upside is that the same battery will live longer ( can be recharged more ) since it isn't being drained down to the lowest voltage the battery supports. The further you continually drain a battery to it's limits, the more you shorten it's potential lifespan.
Another thing that is hard on a battery and also shortens it's rechargeable lifespan is constantly using it at close to it's max C rating and drawing a lot of amps from it. This is one reason I was suprised that Joyetech is even recommending them for use in the Evic as apposed to using a high drain battery such as an IMR. I'll grant them that the Evic is limited on current, but not so much that they aren't pushing the higher mah batteries they are recommending up close to their recommended max C rating which in the long run will be detrimental to the potential lifespan of these batteries.
IMO... These are great batteries to use if you don't plan to use them at say... over 3.7v with a coil that doesn't go lower than 1.8 ohms... that would pull around 2a max and deliver up to almost 7.4 watts of power. If you plan to go past these numbers and draw more current... consider going with an IMR or other high drain battery instead so you can get the most life ( in recharge cycles ) out of your batteries.
Granted, I'm still learning about these batteries, but it has also been my impression that high capacity batteries are more suited to lower amperage applications. I don't fully understand C ratings, but I saw a chart once that listed max current on the AW IMR and Panasonic hybrids at 10amps and these around 6.4, which is still higher that a lot of high capacity ICRs if I'm not mistaken.
The idea that the Evic could use its firmware to get better use out of a battery like this is intriguing. Perhaps at some point they'll even have selectable options based on battery chemistry.
The idea that the Evic could use its firmware to get better use out of a battery like this is intriguing. Perhaps at some point they'll even have selectable options based on battery chemistry.
You may want to go back and actually read the link you provided for these Pan's... it clearly states that the max recommended discharge current is 1C or 2.9a ... not sure where you got the 6.4a from
That link is for the Protected Version, not what GV is carrying.
The review says the recommend discharge current is 1C, 2.9A. It also says the "PCB Protection Trip Current" is 6.7A.
Ha, you're right! I pulled that link from a quick search to show the discharge graph and didn't realize it was the wrong one. This is a rebranded version of the same Panasonic cell Gotvapes is selling:
Test of Intl-outdoor NCR18650B 3400mAh (Black)
It's rated 2C, 6.8a. I've seen the same numbers for the unprotected green Panasonic versions as well. The capacity charts seem to shift slightly to the right with the unprotected version also. I'm assuming the protection circuit affects this, but how the circuit affects C rating is beyond my understanding. rdsok, would a 2C rating make this more suitable for an evic or other vv/vw mod in your opinion?
Dang it... post the wrong link and you've got me preachin' on the wrong info...
( I'm also to blame here because I didn't even read that it was the protected version )6.8a should be more than enough current for any of the VV / VW mod's out there I'd think... at least the basic info I posted is still right if nothing else.
I suspect this is the battery:
http://lygte-info.dk/review/batteries2012/Panasonic NCR18650B 3400mAh (Green) UK.html
The intl output link a few posts up is, it appears, again for a protected panasonic, while gv is carrying the unprotected version (per prior dannoman post).
It's important to have correct information on batteries.
Dannoman, can you confirm if the link I posted is indeed the battery your shop is carrying? Thanks!
http://lygte-info.dk/review/batteries2012/Panasonic NCR18650B 3400mAh (Green) UK.html
The intl output link a few posts up is, it appears, again for a protected panasonic, while gv is carrying the unprotected version (per prior dannoman post).
It's important to have correct information on batteries.
Dannoman, can you confirm if the link I posted is indeed the battery your shop is carrying? Thanks!
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It is, but I didn't see the C rating on that one. That and the other version I posted are the same cell. From my understanding, there are only a handful of battery manufacturers out there, but tons of companies that rebrand them in there own wrapper.
To my original point, this is the graph I would have posted if I had been able to find it at the time. (Too much battery research in my browser history)
AkkuDB
It's got both the Samsung and Panasonic batts. You can see how they're pretty close in the 3.2-3.3 range. The Panasonic keeps going after that while the Samsung needs a recharge. I'm just not sure that most ecigs can use that extra capacity if it requires discharging below 3.2 volts. If WallyO is correct and the eVic could be programmed to use the full capacity, the Panasonic would blow the Samsung away in terms of charge life.
To my original point, this is the graph I would have posted if I had been able to find it at the time. (Too much battery research in my browser history)
AkkuDB
It's got both the Samsung and Panasonic batts. You can see how they're pretty close in the 3.2-3.3 range. The Panasonic keeps going after that while the Samsung needs a recharge. I'm just not sure that most ecigs can use that extra capacity if it requires discharging below 3.2 volts. If WallyO is correct and the eVic could be programmed to use the full capacity, the Panasonic would blow the Samsung away in terms of charge life.
That would get into the guts of the regulator, what its lower input voltage limit is, plus the efficiency when running with a healthy delta V.
Fun stuff
(apologies, dannoman, for the announcement of a cool battery to get into techie land -- nature of the beast)
Fun stuff
(apologies, dannoman, for the announcement of a cool battery to get into techie land -- nature of the beast)
Translation? (for those of us less fluent in Techienese)
It would be really useful that every seller visit this site, and read about li-ion chemistry.
I would begin with basics
I would begin with basics
Dang it... post the wrong link and you've got me preachin' on the wrong info...
I hate when that happens...
I've got a quick question about this battery. I'm thinking about picking one up and wonder about charging. Would I charge it in my eVic like the stock battery or should I get a charger? If it's a charger, can anyone recommend a good one?
I like the xtar wp2 ii, though others are happy with the intellicharger products. Gotvapes carries them.
Test of Panasonic NCR18650B 3400mAh (Green)
The unprotected version, tested up to 5 amp draw. Looks good to me.
Rethinking...
The extra power is not much at 3.4 volts and above, if any, over the various rebranded 2250 mah Panasonic batteries, and none at all over different 2600 mah batteries. Below the 3.4 volt mark, there is a lot of time left.
So a protected(Vape Safe or other) mechanical mod would benefit, you just got to keep an eye on it as it approaches your low cut off that the battery itself provides. Tested above down to 2.8 volts.
A Vamo or such will cut off at approx. 3.4 volts anyway. so not much gained here.
A Kick will cut it off at 3.6 to 3.7 volts so no gain at all with the extra capacity.
Use this link to compare
http://lygte-info.dk/review/batteries2012/Common18650comparator.php
The unprotected version, tested up to 5 amp draw. Looks good to me.
Rethinking...
The extra power is not much at 3.4 volts and above, if any, over the various rebranded 2250 mah Panasonic batteries, and none at all over different 2600 mah batteries. Below the 3.4 volt mark, there is a lot of time left.
So a protected(Vape Safe or other) mechanical mod would benefit, you just got to keep an eye on it as it approaches your low cut off that the battery itself provides. Tested above down to 2.8 volts.
A Vamo or such will cut off at approx. 3.4 volts anyway. so not much gained here.
A Kick will cut it off at 3.6 to 3.7 volts so no gain at all with the extra capacity.
Use this link to compare
http://lygte-info.dk/review/batteries2012/Common18650comparator.php
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