in reading. reviews of batteries in Mooch’s sight, there are several that are rated at 15A, but could go to 20A only if the battery stays at 75C or 80C (30q and vtc6). My question... what does it take to get a battery to that temp? I currently use a Mechanical with a 0.25 single coil build, and single coil squonk if has been my main vape method as of late.
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There's no general rule, too many variables are involved. How long you draw and how quickly and often you draw back-to-back, what the ambient temperature is where you live etc. (and your build as well obviously).
Without battery temperature monitoring, which to my knowledge no mod has (least of all a mech
), there's no way to know what temperatures your batteries reach. Build to the CDR that doesn't have a temp limit or get batteries with a higher CDR if you need more power.
Without battery temperature monitoring, which to my knowledge no mod has (least of all a mech
), there's no way to know what temperatures your batteries reach. Build to the CDR that doesn't have a temp limit or get batteries with a higher CDR if you need more power.
Umm...doing "that thing you're asking about" (discharging at 20A under continuous conditions -- "continuous" here could mean anything longer than a mere fraction of a second, though it will cool back down some in between "duty cycles") is "what it would take." I'm not sure I understand the question? If you're going to do "that" (use it at 20A) then you must keep an eye on the temperature, and stop using before it reaches 75 (or 80) degrees.
Thanks for the reply’s. There’s no way for me to tell what the battery temp is. I guess my question is this; is reaching 80c for a moderate wattage (50-70) with a subohm coil a common occurrence or not? Or would it be more common in a 100+W sub ohm setup.
I completely understand that many variables come into play. I just want to make sure if I run a battery at 18a-20a and that battery does go to say 85 or 90c... am I bowing off my face?!?!
The wattage itself is kind of only a small part of the picture. It's 40°C and you're hitting long draws back to back - or you're sitting on the north pole and taking a 1 second drag every 20 minutes...
It's simply not enough to tell. You have no temperature monitoring => you don't use the temp restricted CDR. Just forget it exists.
I'll repeat my advice: stay below the non-temp restricted CDR or get batteries with a higher CDR if you need more power.
75c = 167f
80c = 176f
Both will feel uncomfortably warm / hot to the touch.
Using a mech 4.2v / .25 = 16.8ish a.
Too many variables in determining how hot & how fast a cell might reach 80c+ to make any reasonable guess.
Why not use a cell better suited to your amp demand instead of pushing 15/20a CDR cells near, to, or past their CDR.
Sony vtc5A 25a CDR
LgHb series 30a CDR
80c = 176f
Both will feel uncomfortably warm / hot to the touch.
Using a mech 4.2v / .25 = 16.8ish a.
Too many variables in determining how hot & how fast a cell might reach 80c+ to make any reasonable guess.
Why not use a cell better suited to your amp demand instead of pushing 15/20a CDR cells near, to, or past their CDR.
Sony vtc5A 25a CDR
LgHb series 30a CDR
I agree with untar. If (since) you have no way of monitoring the battery temperature, it's not safe to use it at a draw that is only safe in conjunction with temperature monitoring. It's as simple as "it's safe to jump out this plane when it's on the runway, but once it takes off, I can only do it if I have a parachute. Since I don't have a parachute, how high can the plane get before I jump out?" You don't have a parachute (temperature monitoring). Don't jump (use the battery) if the plane takes off (draw is over 15A). Keep it under 15A and it doesn't matter (I mean, you'll still want to keep it away from excessive heat, but it shouldn't self-heat to those temperatures, and if the ambient room temperature is 80C then you've got bigger, more immediate problems to take care of. Like getting the hell out of there before you die of heat exhaustion.)
I'm gonna go out on a limb here and say "because those don't have 3000mAh capacity." Although the Sony does get pretty close at 2500.
The 15A CDR won't have 3000mAh either at 20A discharge, the capacity is dependent on the use. It also will have a terrible voltdrop at 20A compared to eg a VTC5A, especially interesting for a mech user.
Thanks for all the help everyone. Yeah I like to stay at 3000mah. I currently am running hg2’s, and my mech mod runs two batteries in parallel so the amp is split over both batteries. However, I’m awaiting the arrival of the pulse 80w regulated, which only uses 1 battery. I ordered some Sanyo 20700b’s and some samsung 30q’s, so I’ll make sure I keep it to 15a!
The math for regulated mods is completely different though
(atomizer)<----|regulator board|<----(battery)
The atty and the battery don't directly communicate like they do in a mech, the board is what makes the decisions. What matters for choosing a battery for a regulated mod is the maximum power you want to use and lowest voltage the regulator will allow ("battery empty" voltage).
max power/(number batteries*lowest voltage) = Amp draw on the battery
If you're setting 60W on the one battery Pulse and it has a low voltage cutoff of 3.2V (I don't know that it is that, I'm just putting a popular number in here) then that means
60W/1*3.2V = 18.75A
Doesn't matter what the resistance of your build is, that's what the maximum Amp draw from your battery will be.
A little bit more if you include efficiency of the board, there will be power loss in the board, often 10% on average is used to approach that, so
18.75A/0.9 = 20.83A
should be what you can expect from your batteries to be drawn at that setting on the Pulse.
(atomizer)<----|regulator board|<----(battery)
The atty and the battery don't directly communicate like they do in a mech, the board is what makes the decisions. What matters for choosing a battery for a regulated mod is the maximum power you want to use and lowest voltage the regulator will allow ("battery empty" voltage).
max power/(number batteries*lowest voltage) = Amp draw on the battery
If you're setting 60W on the one battery Pulse and it has a low voltage cutoff of 3.2V (I don't know that it is that, I'm just putting a popular number in here) then that means
60W/1*3.2V = 18.75A
Doesn't matter what the resistance of your build is, that's what the maximum Amp draw from your battery will be.
A little bit more if you include efficiency of the board, there will be power loss in the board, often 10% on average is used to approach that, so
18.75A/0.9 = 20.83A
should be what you can expect from your batteries to be drawn at that setting on the Pulse.
Utar, that’s very helpful info for the regulated mods, thank you!! So worst case I would be at 18.75 ( hypothetically based on your numbers), and any resistance I add via the coil would lower that.... is that correct?
When calculating battery amp draw using a regulated power device resistance is irrelevant.
No, you're still thinking in mech terms. What your resistance is on a regulated mod is essentially irrelevant, all that matters is the "60W" setting on your mod. Let me "draw" the example from above again
<---------------------------60W---------------------------
(atomizer)<--60W--|regulator board|<--60W--(battery)
The regulator will draw (at least) 60W from your battery. When your battery sits at 4.0V that's 60W/4V = 15A,
when your battery is almost empty and at 3.2V it's the 60W/3.2V = 18.75A calculated above. You see that the emptier your battery gets the more current the regulator will draw to get 60W out of your battery, that's why the lowest voltage the mod allows is so important for choosing a battery.
Don't forget what I said above about efficiency, your board will draw even more from the battery than the calculated Amps because it needs some power for itself to work, that's why I divided 18.75A/0.9 = 20.8A to account for 10% power loss in the board (so if the battery is at 3.2V the regulator will draw 66.5W from the battery to deliver 60W to the atomizer).
The battery getting warm or hot is a consequence of discharging it, not a methodology for ascertaining it's safe usage.
Heat ages batteries, excessive heat damages them.
Use the simple calculations listed above to calculate your amp requirements, then use Mooch's list to pick a battery that satisfies this demand within it's CDR. If one battery cannot, then use two or three.
Heat ages batteries, excessive heat damages them.
Use the simple calculations listed above to calculate your amp requirements, then use Mooch's list to pick a battery that satisfies this demand within it's CDR. If one battery cannot, then use two or three.
I think it is important to remember that these batteries were not designed to be used in a mech or regulated mod. They were designed to be used in a battery pack of multiple batteries and a battery management system (BMS) which monitors battery temperature and for short circuits. They were not designed to be used as a stand alone single or dual cell.
battery pack with BMS
The battery's CDR, set by the manufacturer, assumes that these batteries will be used in a battery pack with BMS. It stands to reason that using these batteries as a stand alone single or dual cell without BMS monitoring it could easily lead to misuse/abuse of the battery. That's why the top battery manufacturers disapprove of us using their batteries for vaping.
As vapers, we have to accept that we are taking a reasonable risk when we use these batteries for an unapproved use. Mooch has emphasized this on numerous occassions.
The battery's CDR, set by the manufacturer, assumes that these batteries will be used in a battery pack with BMS. It stands to reason that using these batteries as a stand alone single or dual cell without BMS monitoring it could easily lead to misuse/abuse of the battery. That's why the top battery manufacturers disapprove of us using their batteries for vaping.
As vapers, we have to accept that we are taking a reasonable risk when we use these batteries for an unapproved use. Mooch has emphasized this on numerous occassions.
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If a battery gets hot in a mech, you'll know it. And it's nothing to try push it's limits for.
Don't be that towel guy.
For normal use you would barely feel the battery getting warmer more than to the touch.
You've gotten great examples above, so i won't venture to deep into it.
Don't be that towel guy.
For normal use you would barely feel the battery getting warmer more than to the touch.
You've gotten great examples above, so i won't venture to deep into it.
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