WHAT DO THE NUMBERS MEAN ON A BATTERY?
In general the numbers relate to the battery size in mm (millimetres). The first being its diameter, the second its length. The fifth is to indicate single cell. For example: an 18650 battery is 18mm in diameter with a length of 65 mm.
Another number found on batteries is the "mAh" rating (milliamp hour), which equates to the amount of stored energy in the cell. The higher the number the higher the potential energy available to be converted into work (vaping in our case) by the end user. This figure expressed in mAh is usually directly related to battery size, but not always. It is indeed possible to have 2 different size batteries with the same "mAh" ratings but the similarities end there.
BATTERY MYTHS - ARE ALL BATTERIES CREATED EQUAL?
Unfortunately no! Batteries are not created equal, regardless of what some folks may say or proclaim. To further exacerbate this dilemma, batteries from the same manufacturer often differ from one another due to poor or non-existent quality control. This has been observed in both length and girth, causing endless frustrations within the vaping community.
WHAT'S THE BEST BATTERY?
In my humble opinion, folks should purchase the best battery they can afford. I am partial to the AW line for quality, durability and consistency. Not all batteries are created equal, and hence my battery of choice is the AW line. Why?
Because AW's quality control and assurance is second to none in the industry in my opinion. When it comes to battery safety, they have gone one step further than many only attempt to achieve.
SHOULD I BUY PROTECTED OR NON-PROTECTED BATTERIES?
This again is a highly subjective topic, with an even more difficult answer. One should only buy protected batteries, whether or not they are intended for use in series or as singular cells. Why?
Some may argue that the protection is only as good as the life of the PCB (printed circuit board) and, like any other electronic component may fail pre-maturely. Although the latter is unquestionably true, the added measure of safety cannot, in my humble opinion, be so readily dismissed or refuted for that matter.
WHAT BATTERY DO I NEED FOR MY DEVICE AND/OR WHICH ONE SHOULD I USE?
It has now become customary for vendors to list their recommendation with regard to which batteries to use with their particular device. This wasn't commonplace not too long ago, but is now becoming the norm. The latter becomes paramount with some of the newer "all mechanical" devices. Why?
Because some of the newer "mods" are being fabricated to close tolerances and many no longer use springs in their devices, to compensate for varying battery lengths. To further exacerbate this problem, batteries from the same manufacturer do indeed have differing lengths of the same battery. Why?
We don't know, but please do not solely rely on the manufacturer's quality control process, as you will be sorely disappointed. When in doubt, use the vendors approved and recommended battery/ries.
BATTERY CHEMISTRY - IS THERE A DIFFERENCE?
Yes there is, and a significant behavioural difference in both safety and general use.
WHAT IS THE DIFFERENCE IF ANY BETWEEN THE DIFFERENT BATTERY CHEMISTRIES?
Lithium Ion (Li Ion) requires a protection circuit for safety, whilst Lithium Iron Phosphate (LifePo4) and Lithium Manganese (LiMn or IMR) use safe chemistry. Although these batteries utilize safer chemistry, protection circuits are generally recommended. The safer chemistry will prevent venting with flames in the event of a catastrophic failure, whilst LI Ion batteries contain and oxidizer, which produces its own oxygen to support combustion, should sufficient heat be available at the source.
Furthermore, the LiMn or IMR battery is capable of handling greater load demands than their cousins the Li Ion and LifePOs (in a much smaller package), and hence is commonly referred to as a "high drain" battery. Providing the battery has the appropriate C rating for the application, these are the recommended batteries intended for use with low resistance atomizers.
WHAT DOES STACKING MEAN?
Stacking is a slang term used to describe connecting the negative end to the positive end while using two or more batteries. The correct term would be connecting batteries in "series" or, using the batteries in "series". When connecting your batteries in "series", you are doubling the voltage while maintaining the same capacity rating (amp hours).
WHAT DOES PARALLEL MEAN?
Unlike in "series", in "parallel" means connecting the positive end of one or more batteries to each other while connecting their respective negative ends together as well. When connecting in "parallel" you are doubling the capacity (amp hours) of the battery pack while maintaining the voltage produced by a single cell. e.g. many hands make for light work.
ARE THERE ADVANTAGES IN USING BATTERIES IN PARALLEL OVER USING BATTERIES IN SERIES?
Yes. The main advantage in using batteries in parallel is, the capability of the batteries to do the work a single cell would prove incapable of doing. Connecting in parallel ensures the workload is shared amongst the cells connected to each other and not overstressing any cell in the circuit. An example using a 14500 900mAh Trustfire battery (The *** fire series battery has a C rating of 1.5):
- This single cell is capable of doing (900mAh/1000)*(C or 1.5) or 1.45A worth of work;
The demand on the battery is 1.6A from an average 2.2 Ohm atomiser. As the battery can only produce 1.45A, the battery will be stressed when current is drawn from the load.
- On the other hand, should we connect 2 or more cells in parallel;
(1.45)*2 or 3 = 2.9 or 4.35A We now have sufficient power available to adequately meet the work load of 1.6A, without stressing any of the batteries in the circuit.
IF I STACK MY BATTERIES CAN I ACHIEVE SIMILAR RESULTS?
No. Because amperage draw is a relation between voltage/divided by resistance or I=V/R. As previously discussed, when we connect our batteries in series we effectively double our voltage while keeping the battery capacity (mAh or I) to do work the same. Once again our 14500 3.7V 900mAh battery:
This single cell is capable of doing 1.45A (900mAh/1000)*C worth of work;
- should we double the voltage (3.7*2) = 7.4V
- applying the formula I=V/R or (7.4/2.2) = 3.36A The workload is nearly 2.5 times greater than the carrying capacity of the "stack", resulting in a seriously overstressed and potential catastrophic condition, especially if unprotected batteries are used.
Is there a way to use this battery pack effectively? Yes, by increasing the resistance of the atomizer used in this application.
- If I=V/R then R=V/I or (7.4/1.45) = 5.13Ohm.
WHY DO WE NEED TO KEEP OUR BATTERIES IN PAIRS?
Because metaphorically speaking, teams that are used to working together perform better. That being said, in battery usage we are trying to keep the internal resistance of the batteries the same, or as close as we can get them to each other.
I HAVE HEARD A TERM "STRESSING A BATTERY". WHAT, IF ANY, EFFECT DOES STRESSING A BATTERY HAVE?
The short answer is rapid aging due the increase build up of cholesterol (or internal resistance), in this particular case caused by excessive work demands. These excessive work demands increase the creation of internal resistance (cholesterol) exponentially, leading to an increased plaque build up (the rock zone).
IS STRESSING A BATTERY DANGEROUS?
Yes, emphatically so.
KEEPING OUR BATTERIES IN PAIRS, WHY?
As seen in the previous discussion, internal resistance in batteries reduces the ability of current to flow. Should one battery contain greater internal resistance than the other in the pair, that battery when called upon to work, will exert itself at an X factor compared to its counterpart. This increase exertion (in trying to keep up with its counterpart) will lead to an increase in internal resistance. As time goes buy, the internal resistance grows exponentially until battery failure occurs.
Because electrical current flows in a closed system, the battery with the lesser internal resistance is trying to push a golf ball through a garden hose (so to speak). This in turn causes an increase in internal resistance of the "good" battery. As the internal resistance in the "good" battery increases, the battery containing the greater internal resistance is stressed even more, once again increasing its internal resistance due to work. Why? Think of it as trying to fight your way through a jungle using a machete when compared to a walk in the park. Which one is less demanding?
HOW DO I ENSURE MY BATTERIES ARE KEPT IN PAIRS?
They are normally received from the manufacture that way. Once received mark the pair with a letter and a number e.g. A1 and A2.
IS THE NUMBER IMPORTANT AND IF SO WHY?
Yes it is. A natural phenomenon takes place in a stack that many cannot explain. The battery closest to the load will discharge quicker than its counterpart. Many theories have materialized over this, but for all practicality, we know it occurs and will leave it at that (in this discussion). You should alternate your batteries in subsequent uses. e.g. If A1 was used on top, A1 should be used on the bottom next time the set is used, and back on top for the following use, and so on, and so on... This will insure a greater distribution of the workload and a more natural and even build up of internal resistance, extending overall battery life. Think of it as rotating the tires on your vehicle, wearing them out evenly.
HOW MANY BATTERIES SHOULD I PURCHASE?
This question carries many possible answers based on specific demands the batteries will be subjected to, dependant on the vaping lifestyle of the end user, battery capacity, and whether the battery is to be used as a single cell or in series application.
Generally speaking 3-4 batteries should suffice in meeting daily demands in single cell applications, with this caveat. The 10440 battery does not have the carrying capacity (320-350 mAh) of other batteries. In this instance I would recommend acquiring at least 6 even 8 cells.
On the other hand if the batteries are intended for use in series, then one would need a minimum of 2 to 3 sets or 4-6 batteries to adequately meet vaping demands.