series vs parallel question

[HighPlainsPuffer]

Hi all, quick question on parallel vs series boxes. I'm debating picking up a dual 18650 box, and am curious about the resulting wattages. With a parallel, the voltage will be whatever a single battery's voltage is, so 4.2 fresh; in a series, these voltages are added so the voltage is 8.4 fresh, right? So with regards to building on each of these boxes, I would need to build at a higher resistance on the series than the parallel if I was looking for the same resulting wattage, correct? For instance, if I've got a .6 build in a parallel box, the output wattage would be slightly under 30 watts. If I use the same build in the series box, the output wattage would be over 100 watts. Is this all correct?

I prefer building at slightly higher ohms (.5 to .9), so it seems a series box would be more fitting for me. That said, as I get more into the non basic coils, if I'm playing with some low resistance claptons I'd be pumping a LOT of power through those coils with a series, so maybe a parallel would be better? Worst comes to worst and if I can't decide I may just get one with a switch in it...

This is of course all based on a nonregulated (bcbox) box, but I figured the question may fit better here over the mech mods subforum.

Thanks!

 

[bzlytbeer]

Wattage in a Series Circuit is Additive, so yes, it could double, or a bit more possibly.

 

[edyle]

dual battery mechs are usually in parallel.

with regulated boxes, dual batteries are usually in series.

 

[dDubs]

The box with a switch to change from parallel to series is a good idea, that way it's versatile. You can use series for high power, or parallel for better battery life.

 

[HighPlainsPuffer]

Thanks for the replies, I definitely see myself using the parallel more than the series, but both would be nice to have for options, so I'm definitely going with a switch capable box! Either that or one of each but at the rate I use mechs, a switchable box makes way more sense!

 

[Nikea Tiber]

Don't forget that operating batteries in parallel also increases the load handling capabilities of the battery so you can also use lower resistance coils to generate higher watts safely. Two 30 amp cells in parallel can handle 60 amps.

 

[K_Tech]

Keep in mind that the switch itself will have to be rated for the max current you're expecting to see.

 

[mcclintock]

Wattage in a Series Circuit is Additive, so yes, it could double, or a bit more possibly.

No. It is squared. 2^2 = 4 times as much power at the same resistance. 30 watt coil gets 120, if the batteries can do it, because current is doubled too. If the coil resistance is doubled (e.g. twice the wraps), then the power is only doubled. Then the current is the same and volts are double.

To get the same power you would need thinner wire and the somewhat less than twice the wraps needed to get the same heat flux from that wire. The series is good if you want a whole lot of power and/or thinner wire less losses etc.; the parallel is good if you just want less battery sag and better life, multiple coils are in parallel usually.