Which is a better choice for 11-15A vaping?

[Kemosabe]

I prefer Samsung batteries and for a while, used 25R cells. Then when the 30Q came out, I went all 30Q.

I was vaping under 15A, and I was enjoying the extra mAh.

But now I'm encroaching on the "limit" (I know 30Q can handle more than 15A safely). I'm a veteran vaper and know a lot about safety- my question is more along the run-time lines.

Will a 3000 mAh battery (30Q) last me any longer than a 2500 mAh (25R5) when I'm running close to or at 15A?

I'm trying to balance mAh and amp limit and wondering at what point (amp level) is the 30Q no longer beneficial with its extra mAh, and what point the 25R5 would be the better choice.

Mooch and the rest of the gurus, I'd love to hear your feedback.

vape on.

 

[Kemosabe]

Oh and I'll add that I recharge my cells at 50%. So the 30Q might be 500 more mAh, but in reality I'm probably only getting 250 more mAh because I don't fully deplete my batteries ever.

 

[Joergl100]

That depends on the type of mod you are vaping! If it is a mech mod, the amps and the power at the coil will get lower by and by, because the voltage gets lower and lower at the same resistance. If you have a regulated device, the amps will rise by and by, because the device keeps the wattage/voltage you have chosen.

 

[Kemosabe]

Right. I should have said I'm using regulated devices. Wattage and resistances vary from setup to setup, but I'm generally in the 12 amp range. At least 10, but no more than 15 currently.

Trying to figure out which batteries will last the longest.

 

[Kemosabe]

...............

 

[Mooch]

The 30Q will probably still give you an extra 10%-15% run time at 15A-20A versus a 25R.

 

[Kemosabe]

The 30Q will probably still give you an extra 10%-15% run time at 15A-20A versus a 25R.

fantastic. thanks a lot for that info. im glad you also added the 20A thing- that helps me too, as i may be in that range eventually.

 

[DaveP]

FWIW, I'm enjoying the MAH feature on my Xtar VC4 charger. If you discharge a new cell down to 3.2V it will give you a MAH rating very close to what the battery is rated for. The MAH feature on the VC4 just calculates the current necessary to reach full charge, so it will vary with a boost charge as opposed to a charge after mod cutoff, but it's a comparative reading that shows battery condition between similarly discharged cells.

That's useful for comparing batteries over time to determine which are beginning to lose capacity and vape time and could be used to compare new cells after purchase. Just run them down to 3.2v and record the MAH rating after charging.

The VC4 is a 4 bay charger, but will only charge at 1A with 2 cells. When I need to charge 3 or 4 at once I use the Efest LUC 4.

 

[Kemosabe]

FWIW, I'm enjoying the MAH feature on my Xtar VC4 charger. If you discharge a new cell down to 3.2V it will give you a MAH rating very close to what the battery is rated for. The MAH feature on the VC4 just calculates the current necessary to reach full charge, so it will vary with a boost charge as opposed to a charge after mod cutoff, but it's a comparative reading that shows battery condition between similarly discharged cells.

That's useful for comparing batteries over time to determine which are beginning to lose capacity and vape time and could be used to compare new cells after purchase. Just run them down to 3.2v and record the MAH rating after charging.

The VC4 is a 4 bay charger, but will only charge at 1A with 2 cells. When I need to charge 3 or 4 at once I use the Efest LUC 4.

Thanks for that info Dave. i do indeed have a VC4. But i thought we had to go below 3.0v to get the true mAh of the cell. i really dont like doing that to my cells, so i never did. the only way i imagined i would be able to estimate the capacity was to deplete them to 3.8v, then double what the final result was. it was giving me varying results, so i kinda just forgot about that feature.

and that was shame because the capacity readout was one of, if not The main reason why i bought a VC4. so im really glad to hear you only need to bring it down to 3.2v to get the full capacity readout when finished charging. i usually charge at 3.7v, but 3.2v is fine with me especially seeing how i'll only need to do it once in a while. its certainly much better than 2.9v!

 

[KenD]

Thanks for that info Dave. i do indeed have a VC4. But i thought we had to go below 3.0v to get the true mAh of the cell. i really dont like doing that to my cells, so i never did. the only way i imagined i would be able to estimate the capacity was to deplete them to 3.8v, then double what the final result was. it was giving me varying results, so i kinda just forgot about that feature.

and that was shame because the capacity readout was one of, if not The main reason why i bought a VC4. so im really glad to hear you only need to bring it down to 3.2v to get the full capacity readout when finished charging. i usually charge at 3.7v, but 3.2v is fine with me especially seeing how i'll only need to do it once in a while. its certainly much better than 2.9v!

The vc4 (and other such chargers) will show the mAh from the charge they're put into the charger to full charge. So no, not the full mAh capacity. And of course, the actual mAh you get out of a battery depends on how hard they're pushed. Nonetheless, chargers such as the vc4 provide an easy way to compare the relative capacity and health of batteries.

Sent from my M7_PLUS using Tapatalk

 

[Kemosabe]

right. so if a battery is rated at 3000mAh, does that mean it'll reach 3000mAh by charging from 3.2v to 4.2v? or is the starting point not 3.2v, but some other #?

 

[Joergl100]

The amount of available watt-hours is more relevant.

Watt-hours (Wh) to mAh conversion calculator

 

[Mooch]

In my experience you want to discharge down to below 2.8V, preferably 2.5V, to measure the capacity via a mAh count during charging. The Samsung 25R graph below gives us some good info. It's a continuous current discharge graph but the capacity vs voltage is the same for pulsed current.

The 25R is rated at 2500mAh. This is at about 0.5A of discharge current though. If discharging at 10A we can see that stopping at 2.8V gives about 2370mAh. If we let this go to 2.5V we would be close to 2500mAh but not all the way there.

But if we look at the capacity at 3.2V when discharged at 10A it's dropped to about 1950mAh.

At 20A down to 2.5V we're probably at about 2400mAh. But at 3.2V the battery only delivers about 1300mAh.

The discharge rate and voltage level can have a fundamental effect on the delivered capacity. Depending on the discharge rate you can see that it really starts to roll off at about 3.0V for lower discharge rates and below 2.8V for higher discharge rates.

Using a charger to measure the mAh put back into the battery after running it down to the mod's cutoff voltage is still a great way though to track its performance and detect any changes. Always do the mAh check after using the same power setting. You'll be detecting changes in capacity of a new battery versus one you've been using for a while instead of just comparing the mAh reading you get against the rated capacity of 2500mAh. But that still works perfectly.

 

[Kemosabe]

thanks Mooch. i knew i hadnt made up the fact that you'd ideally want to drop below 3.0v before charging to find a more accurate mAh value. yet i couldnt find where i had read that info. might have been in the VC4 instruction manual. regardless, i appreciate the input. definitely answers my question.

 

[DaveP]

Off the top of my head, I generally get something around 2000MAH to 2199MAH on my Sony VTC4 and Samsung 25R recharges using the Xtar VC4. To do that, I'm using mods that cut off at 3.2v, so that's my starting point. As Mooch said, if you use that number with a new battery you get a feel for when it's starting to lose capacity down the road.

All chargers have some interesting features. The more I use the Xtar VC4 the more I like the info it provides. It's a shame that it won't charge 3 or 4 18650's at once with 1A current. For charging triple sets, I keep my Efest LUC4 right next to the Xtar.