Dual Batteries and RDAs

[Adam209]

Hey guys and gals

My name is Adam and I am new to the forum. I have a question.
I'm looking into purchasing a sigelei 150w box mod, and I want to get into building my own coils on RDAs. Since the Sigelei 150w a dual battery device, does that mean that I have nearly double the amps to work with? For example, if I use two Samsung 25R 20 amp batteries, does that mean that I have around 40 amps to work with while building on my RDA? I know its not safe to build that high, but Id like to know I have the play room, and that I am plugging the right amperage into my ohm's law calculator.

Thanks

 

[jseah]

If the mod has the batteries in series (which I believe the Sigelei does) then it doubles the voltage. If the mod has the batteries in parallel (i.e. the iStick 100W TC) then it doubles the mah. I'm sure that someone else can correct me if I am wrong, but I believe that doubling the voltage will halve the amp load on each battery.

 

[speedy_r6]

It is a regulated mod. Just keep the resistance in the range the mod can fire(i believe the sig 150 can do down to 0.1ohm). Since you have two batteries, you have the ability to run up to about 120 watts with 20a batteries(this is running to the very limit of the battery at the cutoff voltage), or about 180w with 30a batteries(your mod can't even go that high, so you would have a much larger safety margin with 30a batteries).

With a regulated mod, series and parallel doesnt really make much difference. At the cutoff voltage of 3.2v, a pair of 20a batteries in parallel can put out 40a. That is 128w. A pair of them in series would have the cutoff at 6.4v with a limit of 20a. That also comes out to 128w. A pair of 30a batteries in parallel at the cutoff voltage can put out 3.2v at 60 amps, which is 192w. A pair of 30a batteries in series can put out 6.4v at 30a. Again, this is 192w. When you factor in the inefficiency of the mod, i wouldn't recommend going over 120w with 20a batteries(even at 120, you are basically running them at their limits and probably going to shorten the useful life of the battery). With 30A batteries, go as high as you want.

Keep in mind, the sig150 uses a buck circuit. It can't boost the battery power. Whatever the voltage of the batteries in series is, that is the max voltage it can put out. For example, if you have a 1 ohm build on there and want to run it at 100w, it will need to put out 10v. Since a set of fully charged batteries in series will only put out 8.4v, it simply won't do it. It would only be able to put out 8.4v, which would take you to about 70w. That number will decrease as the batteries drain and the voltage they are putting out goes down. At the cutoff voltage of 3.2v per cell(6.4v in series), it would be maxed out at about 41w.

 

[suprtrkr]

Hi @Adam209 That Siggie is a fine piece of gear. You don't need to worry too much about coil resistance on a regulated mod like the Sig. What counts is the set watts you are using and the voltage the mod kicks out the batteries as too low to work any more. The formula is (set watts) / (battery low voltage x number of batteries) = amp draw on the batteries. Thus, if the mod stops working at 3.5V in the batteries-- most are somewhere around there-- and you set 100 watts, it would be 100 / (3.5 x 2) = 14.29 amps. For best accuracy and safety, you also have to account for the efficiency losses (I^2R losses) on the board itself. Most mods are 90-95% efficient, so guessing 95%: 1.05(watts / volts) = amps, and in our example 1.05(100/7) = 15 amps.

If you don't want to do the math, a good rule of thumb for two-battery mods is, using 20A batteries, maximum watts is 120 and better safety is about 100. If you want more than that, use Sony VTC4 or LG HB6 batteries and you can safely run it out to the maximum of 150 watts. Good 20A batteries are Samsung 25R or LG HE2 or HE4, all at 2500 mAh, and the Sony VTC5 at 2600 mAh, among others. For best battery life (3000 mAh) good 20A batteries are the LG HG2 or the Samsung 30Q.

 

[Adam209]

Thanks guys.
I really don't want to, or find the need to build below .4 ohms. and firing at 50w. Im currently using the Aspire Pegasus with the Cleito tank and I am happy with the .4 ohm addy. But, because I am wanting to learn and get into building on RDAs, I wanted the extra play room. I found the Sig 150 on Wake and Vape (dot) com for only $62, which judging by the reviews is a great deal. I paired it with two Samsung 25R batteries. I know that I'll never use all 150 watts, but again I wanted the peace of mind knowing that it had the play room. Plus, it's sexy as hell. Also, from what Ive read, running the two 20 amp batteries should help me get a little better battery life from the device.

 

[Vaping_Racoon]

Good job keeping vaping safe by getting informed

 

[IMFire3605]

Thanks guys.
I really don't want to, or find the need to build below .4 ohms. and firing at 50w. Im currently using the Aspire Pegasus with the Cleito tank and I am happy with the .4 ohm addy. But, because I am wanting to learn and get into building on RDAs, I wanted the extra play room. I found the Sig 150 on Wake and Vape (dot) com for only $62, which judging by the reviews is a great deal. I paired it with two Samsung 25R batteries. I know that I'll never use all 150 watts, but again I wanted the peace of mind knowing that it had the play room. Plus, it's sexy as hell. Also, from what Ive read, running the two 20 amp batteries should help me get a little better battery life from the device.

The Samsung 25R is a good flexible workhorse, able to give upward to 120w on the Sig150 even though it is a 20amp, you can wiggle it up near 25amps @120watts no problem like the Sony VTC4. Later down the road being you are only @50watts, the LG HG2 3000mah or Samsung 30Q 3000mah might be more up your alley, both are 20amps CDR like the 25R, but that extra 500mah they have will give longer run time per charge, just you can't run them past 100watts

 

[edyle]

Hey guys and gals

My name is Adam and I am new to the forum. I have a question.
I'm looking into purchasing a Sigelei 150w box mod, and I want to get into building my own coils on RDAs. Since the Sigelei 150w a dual battery device, does that mean that I have nearly double the amps to work with? For example, if I use two Samsung 25R 20 amp batteries, does that mean that I have around 40 amps to work with while building on my RDA? I know its not safe to build that high, but Id like to know I have the play room, and that I am plugging the right amperage into my ohm's law calculator.

Thanks

It means you have double the power available compared to using only 1 battery.

0.3 ohms is the sweetspot for the sigelei 150w according to steam-engine.org
Mod range