Well, I can't sleep anyway, here we go:
A dual series mod will us the combined voltage of the batteries and produce a sum total. Example, you have a dual series box with two 18650's. At 4.2 vDC each, the voltage provided to the atomizer will be 8.4 vDC (minus the internal battery resistances and the mod resistance, this is the
voltage drop). In a series configuration, you do not double the current your batteries can safely drain. You may only drain the circuit at a single battery's safe continuous drainage rating (CDR) quantified in amps. Let's say you're using Sony VTC5's. If you'd like to know the lowest resistance you can safely build with the batteries you have in hand, check Mooch's table for the safe CDR of that battery. Use this link:
18650 Safety Grades -- Picking a Safe Battery to Vape With | E-Cigarette Forum
When we check Mooch's table, we see the VTC5 is rated safe at 20 amps. Using Ohm's Law, we determine that with 8.4v DC, to pull not more than 20 amps of current through our circuit, we must ensure our resistance stays above 0.42 ohm. If you don't have the means to measure resistance to a one hundredth of an ohm, round up to 0.5 ohm. The advantage of this circuit, is that we don't have to build at as low of a resistance as we would with a single cell or a dual parallel circuit to get more power (watts) from our build, in this case 168 watts. When you start to drop below one ohm, power climbs very quickly.
A dual parallel mod will use the voltage provided by each battery "independently", and as a result, the voltage of the circuit will remain the voltage each of our cells are rated at separately of each other, in our case, 4.2 vDC (minus the internal battery resistances and the mod resistance, again, the
voltage drop). The cool thing is that in this case, though we're vaping at a lower voltage, we double the current carrying capability of our circuit, and also the milliamp hour rating. Now we can consider our two 20 amp batts to be safe in a parallel circuit configuration to 40 amps, and our cells will last about twice as long as would a single cell or dual series configuration. When we plug and chug our two known quantities (4.2 vDC and 40 amps current) we discover that we can build down to 0.11 ohm producing coincidentally, 168 watts.
Note that the same power is produced in either configuration.
Don't like to calculate Ohm's Law longhand or in your head? Here's the awesome steam-engine.org Ohm's Law calculator:
Ohm's law | Steam Engine | free vaping calculators Note that you can lock in values for our calculations, for vape peeps, typically voltage and current in order to determine resistance.
So in a nut shell, the question to ask regarding series vs. parallel configurations is: do I want the long battery life of the parallel config, or do I not want to have to build my atty at significantly lower resistances that approach short-circuit so I use a series config to obtain the same power? Me personally? I much prefer the added battery life from the dual parallel battery configuration.
In either system, when using any more than one single cell, we must marry our batteries. Ensure the ones you're using are legit quality cells (again, see Mooch's table). Never use E-Fest. They grossly over-rate their batteries and are not very nice people in general.
I would also add that it's 3:49 AM my time. If this turns out to be insomnia fueled rambling tomorrow morning, I reserve the right to change any or all of the post if it turns out to be just stupid
.
