Battery Life Question

[xdarktime]

Hey guys.. so I have a question. For most of my vaping career I've been using Sony VTC4's which are 2100 mah, 30 amp cont. batteries. I just ordered a pair of Samsung 25r's though cuz I've heard that since they have more mah than the VTC4 (2500 vs 2100) that they will last longer in my regulated device. At face value this makes total sense because of the increased capacity. But what about discharge rating? Won't a VTC4 not work as hard as a 25r under--lets say-- a 0.3, 40 watt load? If so, wouldn't the higher discharge rating allow the VTC4 to compensate for the lack of mah capacity, thereby allowing for similar battery life in a regulated (or even unregulated) mod? I'm confused

 

[Madadoor]

The simple answer is No. And 25Rs will last longer in your regulated apv

 

[Rickajho]

It sounds like you are confusing the amp/hour rating and the maximum continuous discharge rating - which seldom have any correlation to each other.

 

[Ryedan]

Hey guys.. so I have a question. For most of my vaping career I've been using Sony VTC4's which are 2100 mah, 30 amp cont. batteries. I just ordered a pair of Samsung 25r's though cuz I've heard that since they have more mah than the VTC4 (2500 vs 2100) that they will last longer in my regulated device. At face value this makes total sense because of the increased capacity. But what about discharge rating? Won't a VTC4 not work as hard as a 25r under--lets say-- a 0.3, 40 watt load? If so, wouldn't the higher discharge rating allow the VTC4 to compensate for the lack of mah capacity, thereby allowing for similar battery life in a regulated (or even unregulated) mod? I'm confused

A little while back I did a comparison of some of the most used vape 18650's these days. The first chart shows them all at 20A. Here is a comparison of the VTC4 and the 25R at 5A.

At 40 watts in a regulated mod, your average draw will be around 12A, so performance will be about half way between the two charts. If your mod shuts down at say 3V under load (probably around 3.2V no load) look at the charts at 3V. You'll see that the lower the amp draw the more advantage you get from the higher mAh while at higher current you'll see more advantage of the higher amp rating. This relationship is I believe pretty typical for these batteries.

 

[DaveSignal]

I don't think regulated/unregulated is relevant. The battery will output whatever current the device/coil allows. The maximum discharge current is a safe recommendation.

With a .3 ohm coil, the maximum current possible with a fully charged battery is 14 amps. Any battery you put in there is going to output 14 amps of current. Both the VTC4 and the 25R can do it safely. But the 25R will last longer.

 

[Ryedan]

I don't think regulated/unregulated is relevant. The battery will output whatever current the device/coil allows. The maximum discharge current is a safe recommendation.

With a .3 ohm coil, the maximum current possible with a fully charged battery is 14 amps. Any battery you put in there is going to output 14 amps of current. Both the VTC4 and the 25R can do it safely. But the 25R will last longer.

With a regulated mod set to X watts, battery (not the mod) amp draw is very similar using a 0.10 ohm coil or a 3.0 ohm coil. It would be identical, but because the regulator chip efficiency varies a bit between minimum voltage out and maximum V out, there will be a bit of difference. Battery amp draw goes up as battery voltage goes down.

Using a regulated mod set to a voltage, coil resistance comes into play, but the calculation is not a simple Ohm's law calc like with a mech mod. Rader2146 explained it well in a blog. Battery amp draw also goes up as battery voltage goes down.

Mech mods are of course simple using Ohm's law, battery voltage and resistance.

 

[DaveSignal]

With a regulated mod set to X watts, battery (not the mod) amp draw is very similar using a 0.10 ohm coil or a 3.0 ohm coil. It would be identical, but because the regulator chip efficiency varies a bit between minimum voltage out and maximum V out, there will be a bit of difference. Battery amp draw goes up as battery voltage goes down.

Ah. I guess it is evident that I don't own any regulated mods . Thank you for the insight.

 

[Ryedan]

Ah. I guess it is evident that I don't own any regulated mods . Thank you for the insight.

You're very welcome