Batteries Questions

[punchy187]

Just starting to understand all the battery lingo and would like some clarification on some things. There are all types of different batteries Li-ion, Ni MH and so on. The difference is some types have better performance in specific areas than others do and vice versa, right? Another thing I have noticed is that all the batteries whether it is AA, AAA, C, or D Cell they all provide basically the same amount of voltage around 1.2-1.5 volts. The difference is how long the life of the battery lasts. The bigger size battery the longer the life of the battery. The life of a battery is measured in milla-amperages or mAh. When you are talking about rechargable batteries the mAh is the measurement of how long the battery will last before you need to recharge it, right? So if I were to use regular non-rechargeable AAA Duracell batteries to make a mod it could be done but you would probably have to change the batteries every hour or so, burning through a tremendous amount of batteries depending on how often you use your mod, right? No matter what batteries you use the magic number in terms of ecig mods is 3.7 as in 3.7 volts because it takes 3.7 volts to generate enough amperage and heat needed to vaporize the liquid, right? Now if all that is correct then I am learning something but still have a few more questions.

1. Why doesn't any battery no matter what the cell size or what it is made from give an amperage rating? Milla amperage is just the size of the bucket so to speak why doesn't any of the batteries give the current or amperate rating like they do for all the other things like voltage etc? Is amperage realative to voltage so whatever the voltage rating is is basically what the amperage is and this ios common knowledge for anyone that understands the basics of ellectricity and/or batteries? Amperage seems to be a very important factor and for some reason is completely absent within the entire world of batteries and battery information.

2. At Fry's electronics they have 2 different models of the rechargeable Li-ion 3.7 volt battery. One of them has a 2600mAh rating and the other has a 1400 mAh rating. The 3.7 volt Tenergy Li-ion battery with the 2600mAh is $8.99 the 3.7 volt Tenergy Li-ion battery with the 1400mAh is $10.99 which leaves me to believe there is something about the 3.7 volt Tenergy Li-ion battery with the 1400mAh is $10.99 that is better than the 3.7 volt Tenergy Li-ion battery with the 2600mAh is $8.99 even though whatever it is must be a secret because it doesn't explain what it would be anywhere on either package. To me they are the exact same battery except the cheaper one has twice the capacity or twice as much life span than the other on so why in the world is it cheaper? It is not a special sale either those are the regular prices.

3. The mod I made I put 2 of the 3.7 volt Tenergy Li-ion battery with the 1400mAh and hooked them up in parallel and noticed the voltage is still 3.4-3.7 volts. Is the only advantage of doing tis is the length of time I can use it before recharging them or is there additional amperage involved by doing this? What if I hooked them up by butting them up together negative to positive would I then get 7.0-7.4 volts? Would that fry the cartomizer wire because of too much voltage/amperage?

P.S. One more question...is it possible to use a capacitor in conjunction with a battery? Wouldn't that give huge bursts of amperage in short spirts which is perfect for use with a mod for getting bigger vapor hits? Along with making the battery last much longer between recharges and ultimately in its life span?

 

[KeithB]

First off, I would HIGHLY recommend heading over to batteryuniversity.com/ and reading everything there several times until you either understand it or learn the questions you need to ask. Then read http://www.e-cigarette-forum.com/fo...?highlight=Exploding+mods+-+current+situation

Batteries are rated in mAh, that's milliamps-hours. A 600mAh battery could provide 600mA for 1 hour, 1.2A (that's 1200 mA) for a half hour and 300 mA for 2 hours. Some manufacturers are reported to be a little optimistic on their ratings however.

The C rating of a battery is also important and is derived from the capacity. A 600 mAh battery would have a C rating of .6A, a 1600 mAh battery would have a C rating of 1.6A.

Li-Ion batteries have many different chemestries but the three you're most likely to run into in the vaping world are LiCO, LiMn, and LiFePO4. They all have different characteristics as far as safe charging rates and max discharge rates which are given a multiple of C. For instance, a 1600 mAh LiCO 18650 battery MIGHT have a max charge rate of .8C (1.2A) and a max safe discharge rate of 2C (3.2A). LiMn and LiFePO4 batteries have different multiples of C for their safe charging and discharging rates. Different LiFePO4 batteries from different manufactures might also be wildly different; some are rated high drain and some are not making some of them suitable for vaping and others not.

Another thing to look for on LiCo batteries (probably the most common type you'll see) is PROTECTION circuits. The might say "Protected" or "With PCB" or they might not say anything at all about protection, like the ones you've referred to above, in which case they are probably NOT protected. Protection circuits are there to reduce the chances of your batteries failing catastrophically due to overcharging, over discharging and maybe short-circuiting. What do I mean by failing catastrophically? Think toxic gasses, flames and explosions, possibly lost teeth and losing a chunk of your tounge. Google Li-Ion battery explosions if you don't believe me. Trying to draw more current than your battery can safely supply is another good recipe for disaster.

1. It'd be nice if all manufacturers had standard labeling. Wattage is what is there real determination of a good vape and is a realtionship between your voltage and the resistance (ohms) of your carto/atty. The voltage and resistance is also what determines the amperage you are trying to draw off your batteries. Read up on Ohm's Law if it's not in the Battery University.

2. I can't really tell what they're selling. That is why I would not use them. There are too many things that effect how safe a battery is to use for vaping and their descriptions don't really mention any of them.

3. Yes, putting your batteries in series will boost your voltage up to around 7.4V maybe 8.4 fresh off the charger and will pop most any carto or atty. There are some very high resistance attys that might take the load, but a better bet would be to use a voltage regulator of some sort, either fixed or vaiable, to drop it back down to 5V (or whatever you like if you go the variable route. I will say DO NOT PUT YOUR BATTERIES IN SERIES. I do not believe the batteries you have are suitable or safe for this purpose.

 

[buGG]

...Batteries are rated in mAh, that's milliamps-hours. A 600mAh battery could provide 600mA for 1 hour, 1.2A (that's 1200 mA) for a half hour and 300 mA for 2 hours. Some manufacturers are reported to be a little optimistic on their ratings however.

The C rating of a battery is also important and is derived from the capacity. A 600 mAh battery would have a C rating of .6A, a 1600 mAh battery would have a C rating of 1.6A.

(C)Rate= Amps (Current)/ Amp hours

 

[shortyjacobs]

(C)Rate= Amps (Current)/ Amp hours

Exactly. The real use of this is amps = C * AmpHours. So a 1600 mAh batt with a "1C" rating can push 1.6 amps. A "2C" rating means it can push 3.2 amps. Your C rating * amphour rating determines whether or not a particular battery can push the amps you require without asploding.

 

[CraigHB]

1. Why doesn't any battery no matter what the cell size or what it is made from give an amperage rating?

It's there. It's given in terms of a cells charge or "C" and a factor of it. For example, a 2C cell with 1400mAh would have a max drain of 2.8A (2 x 1400mA). An 8C cell with 600mAh would have a max drain of 4.8A (8 x 600mA).

Though in a sense, you're right, Cells don't always have their C ratings stamped on them. For a a round ICR cell (Lithium Cobalt chemistry), 2C is usually a safe assumption. This type of cell absolutely must have protection. For an IMR cell (Lithium Manganese chemistry), 8C is usually a safe assumption. IMR cells are typically not protected. The chemistry is "safer", but it's best not to take that for granted. LiFePO4 cells pretty much suck. Don't use them. I don't want to explain why I dislike them so much, but if you really want to know, you can ask.

2. To me they are the exact same battery except the cheaper one has twice the capacity or twice as much life span than the other on so why in the world is it cheaper?

Well, who knows what lurks in the minds of retailers. I use to work in retail when I was going to college and I can say from the experience that prices are wholly based on supplier cost. Usually, there's a set markup across the board. So it could be they bought the higher capacity cells in larger volume and after adding the markup, the price is lower. You can't always generalize because something has a bigger sticker price, the quality is higher. Most of the time, you pay more for a higher capacity battery, but just because you pay less does not necessarily mean the quality is lower.

3. Is the only advantage of doing tis [parallel cells] is the length of time I can use it before recharging them or is there additional amperage involved by doing this?

Putting cells in parallel changes a few things. It doubles the charge capacity (run time), it doubles the drain limit (max current), and halves the internal resistance of the battery (comprising both cells). This typically has minimal effect on power delivered to the atomizer. Though the lower resistance of the battery improves power delivery to some extent, but it's typically not going to be a huge amount.

There is one caveat with parallel cells and that's the high equalization currents that can occur when the cells are initially connected. Better to avoid running cells in parallel if you can, but if the cells are permanently connected or non-removable, it's generally not an issue. If you must do it with removable cells, absolutely use protected cells and make sure you handle them in pairs so they never have a charge mismatch.

What if I hooked them up by butting them up together negative to positive would I then get 7.0-7.4 volts?

Yes.

Would that fry the cartomizer wire because of too much voltage/amperage?

Likely, yes. If not, you'll get a very hot and bad tasting vape.

P.S. One more question...is it possible to use a capacitor in conjunction with a battery?

Short answer, No. Long answer, capacitors have much lower energy density than batteries. Their purpose is to hold small amounts of charge for jobs that don't require much work like signal filtering and conditioning. You don't get something for nothing with a capacitor. A power supply 10 times larger is of no benefit.

 

[punchy187]

@KeithB
@CraigHB

I luckily had a battery still in the package and on the back it had the specs that I am able to understand now after reading your guys post. Before I could not make any sense of it. I uploaded the specs taken from the back of the package. It compares the 2 batteries I asked about in this original post I made. The batteries I have are model 30057 highlighted in green. Take a look.

 

[rickylford]

3. Yes, putting your batteries in series will boost your voltage up to around 7.4V maybe 8.4 fresh off the charger and will pop most any carto or atty. There are some very high resistance attys that might take the load, but a better bet would be to use a voltage regulator of some sort, either fixed or vaiable, to drop it back down to 5V (or whatever you like if you go the variable route. I will say DO NOT PUT YOUR BATTERIES IN SERIES. I do not believe the batteries you have are suitable or safe for this purpose.

I hope I'm not necrophiliating an old post, but this brings me to a question.. If it isn't safe to stack batteries on top of each other, how would you get 7.4volts from two 3.7v 18650 batteries that are side-by-side? (Think the AA battery boxes that come from Radio Shack). If you put two 18650x next to each other in a box like that, how would you get the full 7.4v of the two batteries combined?