Batteries

[Mutley1]

I should add to my above post that the maths isn’t as simple as 65/8.4 as it would be for a series mech, in reality @65W, and on a regulated mod you will be drawing around 4V. With a 30A CD rating that means your good down to about the 0.13 ohm level

Cheers as the mesh strip I will be using mostly is the. Nexmesh turbo 0.13

 

[Mutley1]

I've been running the P42A's in the Odin vaping between 55-65W and they're worked absolutely perfectly for me so I don't think there is any issue with the 30A rating. They're always cool to the touch and seem to be handling the load easily and the higher mAh means longer between charges which I like.

Thanks well I'm caning my geek vape Legend with the profile rdta at 62 watts using molicell P26 & they are cool to the touch [emoji4]

 

[memzey]

I should add to my above post that the maths isn’t as simple as 65/8.4 as it would be for a series mech, in reality @65W, and on a regulated mod you will be drawing around 4V. With a 30A CD rating that means your good down to about the 0.13 ohm level

That's interesting. I was under the impression that on a regulated mod the resistance of the coils was less significant as the chip regulates the circuit but perhaps that isn't the case. I've certainly been vaping builds of less than 0.13 on the Odin (although at wattages considerably higher than 65w) without issue or over heating batteries.

 

[Simon G]

That's interesting. I was under the impression that on a regulated mod the resistance of the coils was less significant as the chip regulates the circuit but perhaps that isn't the case. I've certainly been vaping builds of less than 0.13 on the Odin (although at wattages considerably higher than 65w) without issue or over heating batteries.

nah, it's not less significant... it's irrelevant and it's not used in the equation for working out amp draw on a regulated mod.

 

[Simon G]

@memzey for a regulated mod the calculations are

watts per battery first.... so if you vape at 80w and you have two cells in your mod, that's 40w per cell.

to get the current (amp draw) per battery it's the wattage per battery (40w in this example) divided by the lowest voltage your mod will fire at (usually something like 3.2v) divided by the efficiency of the mod (which is 0.9 typical)

so I have a dual cell mod vaping at 80w...... it's 40 divided by 3.2 (=12.5) divided by 0.9 (=13.88) ... so the maximum amp draw would be just under 14A, so you could use 15A CDR battery safely.

the resistance of the coil doesn't matter (providing the mod can fire it) and unlike a mech, the amp draw increases as the battery voltage depletes. EDIT: and it doesn't matter whether the batteries are series or parallel either, it makes no difference to how you calculate amp draw per cell on a regulated mod.

 

[memzey]

Thanks @Simon G .

I've tried to run that calc for my Odin 200 but I get some strange results. I think this is because the listed lowest voltage is 0.8v. When I use that figure I get higher amp draw than I think I should. Any ideas? Either way the device paired with 42A Molicells runs like champ and the batteries don't seem to get too hot at all.

 

[Simon G]

Thanks @Simon G .

I've tried to run that calc for my Odin 200 but I get some strange results. I think this is because the listed lowest voltage is 0.8v. When I use that figure I get higher amp draw than I think I should. Any ideas? Either way the device paired with 42A Molicells runs like champ and the batteries don't seem to get too hot at all.

Ok, mate, I think this is the confusion... the board might be able to fire 0.8v but what I'm talking about is the voltage in the batteries when the mod says "low batt" and won't fire.... the battery cut off voltage....so the voltage the cell is at when you put it in the charger. (like I said, it's usually somewhere between 3 and 3.3v depending on the mod)

 

[Simon G]

If you don't know then I'd use 3v to be safe as almost all mods will cut off before this.

 

[MajorDanby]

I disagree somewhat...

Series or parallel does make a difference regards the maximum available voltage from the battery and hence the internal circuitry. Although I do take the point that there are sufficient protections to stop your battery exploding.

Power is controlled via modifying the voltage, typically by a buck converter or equivalent (when downrating the voltage)

This effectively consists of an inductor, diode, transistor switch and capacitor. The transistor switches the voltage on/off with the capacitor smoothing out the PD. The other components prevent too high a current from charging the capacitor/prevent flow back through the batteries.

As you increase power you increase voltage and because V=IR, and resistance is fixed (we’ll not consider TC in this example), current also increases.

In a series circuit potential difference is additive, but current through all the cells is the same. As such it is possible to draw more current through the cells than the maximum rated continuous discharge.

Your mod does not know what the rating of the cells is. It will just switch off if it detects a problem with the cells. It is good practise, even in a regulated mod to be aware of battery safety and maintain a continuous discharge below the rating of the cells

 

[Simon G]

I disagree somewhat...

Series or parallel does make a difference regards the maximum available voltage from the battery and hence the internal circuitry. Although I do take the point that there are sufficient protections to stop your battery exploding.

Power is controlled via modifying the voltage, typically by a buck converter or equivalent (when downrating the voltage)

This effectively consists of an inductor, diode, transistor switch and capacitor. The transistor switches the voltage on/off with the capacitor smoothing out the PD. The other components prevent too high a current from charging the capacitor/prevent flow back through the batteries.

As you increase power you increase voltage and because V=IR, and resistance is fixed (we’ll not consider TC in this example), current also increases.

In a series circuit potential difference is additive, but current through all the cells is the same. As such it is possible to draw more current through the cells than the maximum rated continuous discharge.

Your mod does not know what the rating of the cells is. It will just switch off if it detects a problem with the cells. It is good practise, even in a regulated mod to be aware of battery safety and maintain a continuous discharge below the rating of the cells

Fair enough, go and argue with battery Mooch because I can't be bothered.