I thought i knew the basic principles behind the strength and life of these. i thought 2 Efest IMR 800mAh 3.7v 18350 Battery @ 800mah each would be weaker and have less life then 1 - Efest 2600mAh 3.7v 18650 Battery - Button Top @ 2600mah . So my understanding is the one @2600mah is stronger and longer life then 2 800's. Am i wrong?
Confused, 1 - 18650 or 2 - 18350's
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You are correct. I have 2600 mah 18650's for my Vamo V2 and 900 mah 18350's. One 900 mah 18350 lasts me just about all day. One 2600 mah 18650 lasts me about 2.5 days. YMMV depending on battery brand. I haven't used the Efest but people here generally speak well of them.
Why the question?
Why the question?
If you're using them in "shorty" mode, you are correct, an 800mah battery will last about a third as long as a 2600mah. If you use them stacked, use time will increase to about what a 2600mah single battery can do. This is a function of higher efficiency at a higher working voltage for the circuit board in a mod, that will accept stacked 18350s. Here's a link to a test demonstrating this phenomenon -
http://leosedf.blogspot.co.uk/2013/0...tery-test.html
I am not advocating stacked batteries in any device unless and until you are familiar with the hazards and how batteries behave under stacked conditions. It is also important to use a quality charger with any lithium based battery.
(to be read at double speed)
Just my opinion, worth what you are paying for it. Your results and mileage may vary. No warranty or guaranty is expressed or implied. The end user accepts all liability and culpability and holds the poster harmless of any and all potential damages. I am not a scientist, chemist or physicist and hold no degrees in anything nor do I play any of those on TV.
http://leosedf.blogspot.co.uk/2013/0...tery-test.html
I am not advocating stacked batteries in any device unless and until you are familiar with the hazards and how batteries behave under stacked conditions. It is also important to use a quality charger with any lithium based battery.
(to be read at double speed)
Just my opinion, worth what you are paying for it. Your results and mileage may vary. No warranty or guaranty is expressed or implied. The end user accepts all liability and culpability and holds the poster harmless of any and all potential damages. I am not a scientist, chemist or physicist and hold no degrees in anything nor do I play any of those on TV.
I was asking on another thread i saw a person stateing that she gets stronger hits with stacked in a Vamo, I thought it would be the opposite. Or actually the same due to its regulated with the APV but should last longer. I didnt want to hyjack her thread so i started this one.
Ahhh, I never stack them so my answer is based on shorty mode. Stacking means you have 8 volts (4 + 4, stacked your batteries are in series and voltages add together) when they are charged. This means the device doesn't have to do much to get voltages higher than you 18650 voltage of a little over 4 volts on a fresh charge. This is very simplified.
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All I can say is that if you do stack batteries, be sure you understand what you're doing. Mistakes can cause some serious problems that no one wants to experience.
The first thing is that power is a function of volts times amps. In the case of your 18650, 2.6 times 3.7, which equals 9.62 available watts. With the 18350s, stacked, it becomes 7.4 times .8, which equals 5.92 available. An apparent power difference of almost 4 watts. This difference is made up for by the electronics of the regulator. A Vamo uses a "boost" circuit to raise voltages lower than 6 volts to that 6 volt level. It then pulses that 6 volts to achieve the desired power level. In a stacked battery situation the boost circuit does not operate, instead a regulator lowers the voltage to 6 volts and that 6 volts is also pulsed to achieve the desired power level.
The boost circuit is rather inefficient, consumes a lot of power just to operate, and that power is in addition to the power delivered to the atomizer. A regulator is quite efficient and uses very little power to operate, as in milliwatts, so there is a significant gain in overall efficiency that makes thing almost equal. I have some notes, somewhere on my desk, from taking measurements of current consumption using both a single 18650 and a stack of 18350s. The current is less than half with the stack if I remember correctly.
My own experience is that the "hit" is the same, but they both last almost exactly the same amount of time, or milliliters of liquid vaped. This also assumes that you are using the Vamo, or other APV, in the "watts" mode.
The first thing is that power is a function of volts times amps. In the case of your 18650, 2.6 times 3.7, which equals 9.62 available watts. With the 18350s, stacked, it becomes 7.4 times .8, which equals 5.92 available. An apparent power difference of almost 4 watts. This difference is made up for by the electronics of the regulator. A Vamo uses a "boost" circuit to raise voltages lower than 6 volts to that 6 volt level. It then pulses that 6 volts to achieve the desired power level. In a stacked battery situation the boost circuit does not operate, instead a regulator lowers the voltage to 6 volts and that 6 volts is also pulsed to achieve the desired power level.
The boost circuit is rather inefficient, consumes a lot of power just to operate, and that power is in addition to the power delivered to the atomizer. A regulator is quite efficient and uses very little power to operate, as in milliwatts, so there is a significant gain in overall efficiency that makes thing almost equal. I have some notes, somewhere on my desk, from taking measurements of current consumption using both a single 18650 and a stack of 18350s. The current is less than half with the stack if I remember correctly.
My own experience is that the "hit" is the same, but they both last almost exactly the same amount of time, or milliliters of liquid vaped. This also assumes that you are using the Vamo, or other APV, in the "watts" mode.
I'm interested in this too as I'm just about to pull the trigger on batts for my SVD which is in transit.
My understanding that stacked batts in a regulated device like an SVD or Vamo is fine as long as you are somewhat careful about keeping them married etc...? Is there really a danger.
I definately want to be able to go somewhat stealth so I was going to get 4 18350 - 2 to keep as a pair and 2 for exchanging in shorty mode.
Maybe I should get 2 18350 for swapping and 1 18650 for at home?
Awsum, you seem to be saying that regulating when using stacked is more efficient, but in the end it works out to the user as the same as an 18650, which is overall a safer option? So for me I guess either 1 18350 or 1 18650 in at a time and I'm set...
My understanding that stacked batts in a regulated device like an SVD or Vamo is fine as long as you are somewhat careful about keeping them married etc...? Is there really a danger.
I definately want to be able to go somewhat stealth so I was going to get 4 18350 - 2 to keep as a pair and 2 for exchanging in shorty mode.
Maybe I should get 2 18350 for swapping and 1 18650 for at home?
Awsum, you seem to be saying that regulating when using stacked is more efficient, but in the end it works out to the user as the same as an 18650, which is overall a safer option? So for me I guess either 1 18350 or 1 18650 in at a time and I'm set...
From a safety aspect, a single battery is always safer. Stacked batteries should be "married" and used as a stack, never as singles. Voltage, after charge, needs to be checked and they should be VERY close to identical. That's why I think a quality charger is in order, preferably one with a built in voltmeter. As far as one being equal to the other, check the link to the blog I posted above. The results are rather surprising. With all the "horror" stories about stacked battery problems, it amazes me that batteries are used in stacks in many tactical flashlights with no reported serious problems, just sayin.
Personally, I don't care about stealth mode and am interested in how long I can get out of a battery, or pair, before needing a recharge.
Personally, I don't care about stealth mode and am interested in how long I can get out of a battery, or pair, before needing a recharge.
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