Battery Charger question...

[matthawk7]

So I've had my midi-vapestack for a couple of weeks and it rocks!
I'm a little disappointed in the battery life though...I get about 8 good hours using a LR atty and maybe 10 using a standard. My 650mah ego lasted just as long.

I opted for the cheap charger from madvapes and was wondering if that could be the issue?

Any thoughts or other ideas? I have the standard blue 18350 batteries also. Just seemed odd that most of the reviews I've seen of the roughstack using the same battery gushed about the battery life being 12-15 hours. Thanks!

 

[Drozd]

well vape time will depend on every individual and what atty they are using...

as well as sorry but those batteries arent the best ...they get overstressed...so the more you use them eventually the shorter amount of time they'll last...

but I'll show you the math...

let's say you're using that battery 1200mAh right and a 2.2Ω 510 atty...

a 2.2Ω atty at 3.7V has an amp draw of 1.68A

the max drain rate of the battery is the mAh rating of the battery times it's C rate (we know that UF batteries have a 1.5C rating)
so the max drain rate is: 1.8A

so like I said it's really close to being overstressed with a standard resistance atty...

so you can take the amp draw of the atty and divide by the mAh rating of the battery and that'll give you the c rate of discharge.... divide 60 minutes by that and it'll give you the # of continuous minutes that it'll run (multiply by 60 to get seconds)
so
1680mA/1200mAh= 1.4C.... 60min/1.4C= 42min (or 2571 seconds)

you'd divide that by however long you hold the button for on average and it'll give you # of button presses.... average how many button presses you take in an hour....
2571sec is.... 514 button presses...if you hit the button once a min (for 5 seconds long) that's about 8.5 hours....

if you switch out for the LR atty then the battery is definitely overstressed
a 1.5Ω lr atty at 3.7V has an amp draw of 2.47A

that's way more than the max drain rate on the battery of still 1.8A

but following the same math for time

2470mA/ 1200mAh = 2.06C ... 60min/ 2.06C= 29min (or 1747 sec)
which breaks down to:
349 button presses (at 5 sec long) .... which would be 5.8 hours if taking one button press a minute

so really like I said it comes down to how often you press the button and which atty you're using....the math will give you a rough idea of how many seconds it'll last with an atty of a given voltage...

 

[HzG8rGrl]

well vape time will depend on every individual and what atty they are using...

as well as sorry but those batteries arent the best ...they get overstressed...so the more you use them eventually the shorter amount of time they'll last...

but I'll show you the math...

let's say you're using that battery 1200mAh right and a 2.2Ω 510 atty...

a 2.2Ω atty at 3.7V has an amp draw of 1.68A

the max drain rate of the battery is the mAh rating of the battery times it's C rate (we know that UF batteries have a 1.5C rating)
so the max drain rate is: 1.8A

so like I said it's really close to being overstressed with a standard resistance atty...

so you can take the amp draw of the atty and divide by the mAh rating of the battery and that'll give you the c rate of discharge.... divide 60 minutes by that and it'll give you the # of continuous minutes that it'll run (multiply by 60 to get seconds)
so
1680mA/1200mAh= 1.4C.... 60min/1.4C= 42min (or 2571 seconds)

you'd divide that by however long you hold the button for on average and it'll give you # of button presses.... average how many button presses you take in an hour....
2571sec is.... 514 button presses...if you hit the button once a min (for 5 seconds long) that's about 8.5 hours....

if you switch out for the LR atty then the battery is definitely overstressed
a 1.5Ω lr atty at 3.7V has an amp draw of 2.47A

that's way more than the max drain rate on the battery of still 1.8A

but following the same math for time

2470mA/ 1200mAh = 2.06C ... 60min/ 2.06C= 29min (or 1747 sec)
which breaks down to:
349 button presses (at 5 sec long) .... which would be 5.8 hours if taking one button press a minute

so really like I said it comes down to how often you press the button and which atty you're using....the math will give you a rough idea of how many seconds it'll last with an atty of a given voltage...

I want the corset that has this statement burned into the leather! LOL

 

[matthawk7]

awesome explaination! I don't even know if they make this battery in a high drain version. Would that help? Time for more research...
M

 

[Drozd]

no they don't but they do make a high drain 16340...

and since the battery # is an expression of the size (first 2 numbers are diameter, second two are length, and the last 0 stands for cylindrical cell)

so technically one is 18mm diameter x 35mm tall
and the other is 16mm diameter x 34mm tall

a high drain 16340 should fit with a little bit of rattle due to dimension

 

[brian5470]

Another supplier that I know of on here sells IMR high drain 18350 batteries. I don't know if there is a difference in in fit though.

 

[Drozd]

Another supplier that I know of on here sells IMR high drain 18350 batteries. I don't know if there is a difference in in fit though.

they could possibly...but not all high drain batteries are created equal...
there are several suppliers that carry BDL made IMR batteries which are lower quality and I believe to be pretty much trash...

when I say high drain IMR I personally am only talking about the AW IMR high drains..

 

[matthawk7]

It seems as though any LR atty would overstress a standard battery. Do high drain batteries have a higher C rate? What makes them high drain? This was my first battery mod and (coming from a former ego user) I do seem to see a fairly steep drop off after 20 mins or so. I really need a multimeter...
M

 

[Drozd]

It seems as though any LR atty would overstress a standard battery. Do high drain batteries have a higher C rate? What makes them high drain? This was my first battery mod and (coming from a former ego user) I do seem to see a fairly steep drop off after 20 mins or so. I really need a multimeter...
M

yes they have a different chemistry (lithium Manganese versus Lithium cobalt) and thus a different c rate... the manganese has a lower resistance and thus a higher drain rate

C rates as I know them:
Generic no name Li-Ion can assumed to be 1C
*fire Li-Ion 1.5C
AW Li-Ion 2C
BDL LiMN high drain 10440 3C
BDL LiMN high drain 14500 5C
AW LiMN 14500 and 16340 size 8C
AW LiMN 18650 10C
AW LiFePo4 3V 16340 10C

*tenergy lists their LiFePo4 3V 16340 batteries and just a max drain rate of <550mA

so even the BDL high drain 10440 arent sufficient and their high drain 14500 are borderline....they also have questionable QC reputation.. that's why I personally am not trusting of their 18350 high drains either.. they've proven their quality and performance to be lower with their other batteries that I wouldnt even bother to look at them

 

[matthawk7]

So (again...wishing I had a multimeter), if I enjoy the first hour of vapin using my ultrafire 18350, switching to a high drain 16340 would give that feeling for a longer time? I know total runtime would probably drop, but it would at least feel "fresh" longer? Those AW 16340's are a LOT more expensive... Where's the best place for them?

What about these? #1 Batteries for Mods

 

[Drozd]

So (again...wishing I had a multimeter), if I enjoy the first hour of vapin using my ultrafire 18350, switching to a high drain 16340 would give that feeling for a longer time? I know total runtime would probably drop, but it would at least feel "fresh" longer? Those AW 16340's are a LOT more expensive... Where's the best place for them?

What about these? #1 Batteries for Mods

yeah they should feel fresh longer...

additionally in theory they should seem like they last about the same amount of time... the reason being is that they deliver the full amp draw that your atty is asking for so there's no voltage sag so they feel like they hit harder even fresh... because of that you tend to hold the button for a shorter period of time to get a satisfying hit... so even though they'd last shorter amount of time continuous... it's be close to the same if you're taking 3 second long hits instead of 5 second long ones...

as for the nhaler ones.... I have the same opinion on them as I've expressed on the BDL ones (not sure if that's who make the nhaler ones or not)... but the only ones I will vouch for or use myself are the AW ones (I get them from lighthound or directly from the AW reseller on CPF)

 

[matthawk7]

OK, I guess they're not that much more...the few links I looked into listed them at like 15 bucks each! I threw in a cheap BDL one from COV until I can try some real AW ones. Thanks for the info! Nothing like one more variable in an already complex equation.

 

[Andrew Stallings]

keep in mind.....those Chinese Trustfire batteries are always overrated as far as capacity. I've got a couple dozen that I charge on a digital charger, and with a charge cutoff of 4.1V I get on average a little over 50% of their rated capacity, but they're hit or miss. Can't beat em for the price, but just don't expect to get the rated capacity out of them.