I've finished my study into 'batteries for vaping technology'.
I carried this out on one of the top battery forums www.candlepowerforums.com
Below is the link to the conclusion post:
However.... although the best batteries are indicated, this post does assume the reader has followed the thread.
Obviously this can be done; but to shortcut that, for those that are only actually interested in choosing the right batteries, and would like a quick explanation.... here it is:
Simple Vaping Tech: Battery, switch, coil
The ideal battery is one that maintains a given voltage, until it fails.
The reason for this is that, as the voltage drops, so does the energy in the heating coil.
This means that the vaping experience can change over the cycle of the battery - starting at say 4.2v running down to possibly 2.5v, (total depletion of charge).
Such an ideal battery is not commercially available to us, so the next best thing is to find one that only drops its voltage slightly (before near immediate total depletion).
These batteries DO exist
Two types of power delivery
There are many types of batteries and cell chemistries, but as far as we are concerned, there are two methods of delivering power.
1. Voltage insensitive - provide power for as long as possible, on a slow path down to zero.
Choose these batteries for your torches/flashlights.
The light will get dimmer, but you'll see it getting dimmer, so perhaps you'll preserve power where you can.
2. Voltage sensitive - provide power in a tight voltage range, and when it passes the range, it fails almost immediately.
Ideal for vaping, or any simple technology that has no voltage transformers.
Why are we not told this???????
I've been into technology all my life.
I've gone through probably thousands of batteries.... some of which just fail, while others just get weaker.
At no point have I ever seen this explained on any battery packaging.
I know batteries are complex beasts.... but this is very easy to understand......AAAAGH!
Back to the post:
To be certain..... the only way of knowing which is which, is by using a wonderful app created by a battery expert, who not not only programmed the app, but then tested all the batteries.
Er.... nice one HKJ
Here is his battery comparator
However... by studying his test results, I have discovered a basic rule of thumb for 18650 batteries.
Pretty much every (perhaps all) 2600 mAh cells provides a tight voltage range.
Pretty much every (perhaps all) 3400 mAh cells provide a long slow drop.
IE. for vaping 18650 batteries, always go for 2600 mAh and not the more expensive 3400 mAh cells
2800 & 3000 mAh cells are usually slow drop, but one or two may not be.
However, if you choose the cells I recommend, then they are anyway about as good as it gets, regardless of what the manufacturers have printed on the battery (which is very often meaningless).
The vaping voltage range:
4.0v - 3.5v
The Top Batteries for this range:
1. Efest 18650 IMR 2250mAh
This cell has been tested as the 18650 2250mAh bt (black).
We can see that the cell drops to our 3.5v reference point quicker by around a third, against the Sanyo.
They ship worldwide for free, therefore it is available to all.
2. Efest 18650 LiIon 2600mAh protected or Xtar variant
Efest produce different coloured cells, giving different results, some exactly as the sanyo (probably is a sanyo, but for this variant it's not clear).
Xtar state that this is a sanyo cell, so it is most likely to mimic the performance of that cell.
3. Sanyo 18650 LiIon 2600mAh unprotected
The reference cell, available everywhere, considered very good quality, best flat voltage drop curve - only unprotected.
Note: Please be aware of battery safety - read my conclusion post
In fact The Sanyo above is probably the No 1 battery on the planet in this range, and is used by many battery retail/re-manufacturers (eg. xtar above).
This cell will deliver 3.5v+ at 1 amps constant(!) for 2.4hrs.
In comparison, the Efest3400 mAh cell hits 3.5v at only 1.9hrs.
Plus, you will have paid a shed load more money for the 3400mAh battery!!!
(Note: halving these figures for a 2 amp current should be about correct).
Complex Vaping Tech - Variable voltage and watts
So, you have the fancy gear that can fix the voltage output, even though the battery voltage is dropping?
But the best tech is now where you can fix the Watts Ie. the system checks the resistance of the atomiser coil, and you simply dial in the amount of energy to put into the coil.
Very nice indeed.
The great thing about this 2nd generation complex kit, is that the chips they use offer much more control capabilities.
Most, if not all, have a voltage cutout at 3.2v.
This prevents you from destroying the battery, by trying to extract power that no longer exists.
@Grenage - I'm wondering if your kit has a voltage cutout, cos you mentioned your getting about 2 months use per cell ie. around 60 cycles.
The fact is, that if you change your cell at 3.5v you will get more cycles out of the battery.
However, if you are taking it to the 3.2v limit, you might get a little bit more time out of the cycle of a high quality 3400mAh cell.
Having said that...... considering the costs.
My recommendations are that the above cells offer the best performance/price ratio for both simple, AND complex vaping technologies.
The other battery ranges:
For the custom built cells that are provided for most e-cig/cigar type tech..... who knows what you're getting, without actually testing.
In an earlier post re old grey wolf: http://ubuntuforums.org/showthread.p...7#post12587287
We discussed a std battery replacement tube using 14500 range batteries.
I have to presume (guessing) that within that range, the manufacturers also offer the two choices mentioned above..... but also.... without informing the purchasing public
I haven't researched this range, but the information must be out there (Mulder)
Actually... I've just looked, and here is a link showing six 14500 cells being tested (page down to find them)
And here is another.
Update: Just had a closer look at the graphs for the 14500 cells.
The AW 750mAh drops to 3.5v in around 100mins.
The Yezl 900mAh drops to 3.5v in around 60mins.
The AW 750mAh is far and away the best battery for vaping.
Note: These times are for current draw of 0.5 amps.
However, HKJ has inputted the 14500 data into the comparator, allowing for perfect comparisons until the best is found.
Can't beat that!