Confusion about dual Batt Box mods and Amps

[Spencer87]

Ok, So If I have a 20 Amp continuous batteries,
I recognize the ohms law and All that... and know how to do the calculations.

Now, I am wondering. If I got a dual battery box mod, does it immediately UP the Amp discharge to a continuous 40amp?

I dont have a dual battery mod yet, but I am thinking about getting one IF it does that.
If not, then not much point.

 

[Wraith504]

Ok, So If I have a 20 Amp continuous batteries,
I recognize the ohms law and All that... and know how to do the calculations.

Now, I am wondering. If I got a dual battery box mod, does it immediately UP the Amp discharge to a continuous 40amp?

I dont have a dual battery mod yet, but I am thinking about getting one IF it does that.
If not, then not much point.

Depends on the batteries are in series or in parallel. in series you would just about double the voltage ie 2 batteries at 4.2 in series is 8.4 volts. but most i believe are in parallel which will just about double the mah or capacity/runtime. The amperage rating will always be that of the lowest rated battery in the circuit. If you want 40amps cont look into 26650s

 

[Froth]

amperage rating will always be that of the lowest rated battery in the circuit.

False. With identical batteries in parallel the load is split over two cells, so if you have two identical 20A batteries it is entirely possible to discharge 40A if they are wired parallel. You also cut the internal voltage drop in half with a pair of batteries in parallel.

Edit: Proof. - http://batteryuniversity.com/learn/article/serial_and_parallel_battery_configurations Check figure 3 - " Figure 3: Parallel connection of four cells With parallel cells, the current handling and runtime increases while voltage stays the same. "

 

[Wraith504]

False. With identical batteries in parallel the load is split over two cells, so if you have two identical 20A batteries it is entirely possible to discharge 40A if they are wired parallel. You also cut the internal voltage drop in half with a pair of batteries in parallel.

Edit: Proof. - Serial and Parallel Battery Configurations and Information Check figure 3 - " Figure 3: Parallel connection of four cells With parallel cells, the current handling and runtime increases while voltage stays the same. "

Yes i see that the amperage will essentially double to 40, now the question becomes is it safe? i personally wouldnt draw 40 amps from 2 20 amp batteries in parallel would you?

 

[Froth]

Yes i see that the amperage will essentially double to 40, now the question becomes is it safe? i personally wouldnt draw 40 amps from 2 20 amp batteries in parallel would you?

I've done it before and would do it again, if your batteries are paired well and are the same starting voltage and you monitor them it's no less safe than pushing a single cell to the discharge limit.

Edit: I've seen these boxes perform, they are NASTY. (http://vosvape.com/products/copy-of-aluminum-triple-18650-vbx-box-mods-volt-meters-added) They also make a triple parallel 26650 believe it or not, and it can push over 120A depending on batteries.

 

[Wraith504]

I've done it before and would do it again, if your batteries are paired well and are the same starting voltage and you monitor them it's no less safe than pushing a single cell to the discharge limit.

Now wouldnt it be easier to run a 26650 vs having to worry about 2 cells venting rather than one?

 

[Froth]

Now wouldnt it be easier to run a 26650 vs having to worry about 2 cells venting rather than one?

Nope. Parallel 18650 also gets you more capacity/mah and more amperage than a single 26650 ever will. 26650's have a lot more material and thus more energy to vent versus an 18650, the likelyhood of both batteries venting at the same time in a parallel mod is almost 0.

 

[ukeman]

Nope. Parallel 18650 also gets you more capacity/mah and more amperage than a single 26650 ever will. 26650's have a lot more material and thus more energy to vent versus an 18650, the likelyhood of both batteries venting at the same time in a parallel mod is almost 0.

Parallell sounds like a good way to go... for more batt time (mah) and more amps/watts.

What are the benefits of in series batts?

 

[Froth]

What are the benefits of in series batts?

The obvious "benefit" is double voltage, now that is all well and good but for a mechanical device with no sort of circuitry you will likely see no real benefit, because of the higher voltage and thus more heat you may actually be able to burn through more juice but you will likely not see any increase in overall run time on a mechanical, so basically don't do it! Now with a VV/VW device it is entirely different, for example if you always vape your VV/VW device at the same setting it is always going to output the same amount of power until the battery sags too low to fire, if you increase the voltage with batteries in series but you keep the device output the same as before you gain run time because less current is needed from each cell due to the higher voltage supplied to produce the same device output power. That is if the VV/VW device can even take 8.4v without frying the circuitry.

Basically to sum up what I just said - If your device uses a constant amount of power it will use less current when it is fed a higher voltage from batteries in series.

Edit: For vaping, there really is not much benefit to series batteries in all but a select few VV/VW devices. Especially when you consider that ideally you want each battery in series to be identical, even from the same manufacturing batch if possible.

 

[ukeman]

'thanks for the info... its all a big maze trying to define the differences and I guess it depends on how well one understands electronics which I am pretty sad when it comes to it.
I've got a couple of Raptor 120w boxes, because I was into strictly sub ohms for a year, and they max at 6v, but can have lots of watts.

Lately I've appreciated dna boxes because you can go with LR resistances (1 to 2 ohms) with thin wire coils, and crank up the voltage; the dna30 has up to 9v ! I use these with my favorite atomizers (single coil RTA's)

Now the Sig100 can also go up in volts (T8 etc too)... so imo those are pretty good for whatever you want to build; wide range in watts AND voltages.

I know there are things like "step down" and "boost" but I still don't know what the differences and strengths of how the double batts are configured ... I've been reading but even now its a puzzle.

 

[Wraith504]

Nope. Parallel 18650 also gets you more capacity/mah and more amperage than a single 26650 ever will. 26650's have a lot more material and thus more energy to vent versus an 18650, the likelyhood of both batteries venting at the same time in a parallel mod is almost 0.

But you only have to be concerned with one battery with the 26650 vs having to monitor 2 18650s. Those odds are simple 2 batteries 2 chances for failure, 1 battery only 1 chance so I actually decrease the odds of venting that way

 

[edyle]

Ok, So If I have a 20 Amp continuous batteries,
I recognize the ohms law and All that... and know how to do the calculations.

Now, I am wondering. If I got a dual battery box mod, does it immediately UP the Amp discharge to a continuous 40amp?

I dont have a dual battery mod yet, but I am thinking about getting one IF it does that.
If not, then not much point.

2 20 amp batteries in parallel will be capable of 40 amps.

 

[Spencer87]

I am wondering for 1) ohms, more batteries means lower ohms safely. I can go down further. So does it remain same voltage.
2) saw the God mod, it's vw But I've seen some wooden mech mods, so I wondered.

 

[Froth]

But you only have to be concerned with one battery with the 26650 vs having to monitor 2 18650s. Those odds are simple 2 batteries 2 chances for failure, 1 battery only 1 chance so I actually decrease the odds of venting that way

If you want to think you're right you're more than welcome to but the fact remains that a 26650 will vent much more violently than a 18650. Remember, the device that EXPLODED at vape blast was a 26650. With batteries in Parallel there are not more chances for a battery to vent, but if you want to think that to appease your own ego please be my guest and continue to believe whatever you would like because it has become blatantly obvious to me that you're lacking in battery/electrical knowledge but seem to think you know everything.

 

[Ryedan]

But you only have to be concerned with one battery with the 26650 vs having to monitor 2 18650s. Those odds are simple 2 batteries 2 chances for failure, 1 battery only 1 chance so I actually decrease the odds of venting that way

This doesn't make sense to me either. To my knowledge, there is no more risk in running two 20A batteries in parallel and drawing 40A from them than running one 20A battery and drawing 20A.

Also, there are no 40A continuous discharge batteries in either 18650 or 26650, so if you need that much power, you need two cells.

If you're just interested in more mAh at less power it still wouldn't matter to me in terms of safety, though you can get more mAh out of a 26650 than a 18650 so you have more options.

 

[Frenchfry1942]

Sooo, if I understand this correctly, I just ordered a DNA30 Mod with dual batteries. Now, I really have no intention of using 40A, what I was thinking was that I would have more mAH. I was intending to buy 4 18650 VTC batteries and when 2 are charging, the other two are loaded in the MOD.

...Am I missing something? Thanks for helping.

 

[Wraith504]

This doesn't make sense to me either. To my knowledge, there is no more risk in running two 20A batteries in parallel and drawing 40A from them than running one 20A battery and drawing 20A.

Also, there are no 40A continuous discharge batteries in either 18650 or 26650, so if you need that much power, you need two cells.

If you're just interested in more mAh at less power it still wouldn't matter to me in terms of safety, though you can get more mAh out of a 26650 than a 18650 so you have more options.

Dont the sony 26650 vts have like 40 amp continuous?

 

[Wraith504]

If you want to think you're right you're more than welcome to but the fact remains that a 26650 will vent much more violently than a 18650. Remember, the device that EXPLODED at vape blast was a 26650. With batteries in Parallel there are not more chances for a battery to vent, but if you want to think that to appease your own ego please be my guest and continue to believe whatever you would like because it has become blatantly obvious to me that you're lacking in battery/electrical knowledge but seem to think you know everything.

2 cells one can discharge at a faster rate than the other. you have to monitor 2 cells. with a 26650 you are only monitoring one cell. So technically speaking the odds of a venting battery are greater with 2 cells. You have 2 chances to vent a battery vs 1. A 2 year old can figure that math out. Noone said which would be a more violent vent it was the odds of venting. 2 batteries 2 chances 1 battery 1 chance.

 

[Wraith504]

Not to mention if you have one 18650 vent there is probably a pretty good chance the one sitting right next to it is going to end up venting due to heat alone

 

[edyle]

Sooo, if I understand this correctly, I just ordered a DNA30 Mod with dual batteries. Now, I really have no intention of using 40A, what I was thinking was that I would have more mAH. I was intending to buy 4 18650 VTC batteries and when 2 are charging, the other two are loaded in the MOD.

...Am I missing something? Thanks for helping.

1: Yes you will have more mah.
2: Yes while you've got 2 charging, you have 2 in the mod.