How Many Charges?

[Alien Traveler]

Because the battery requires time to cool to ambient and to re-order it's internal electrical charge state after use and after charging. Similarly, they should not be taken directly off the charger and put in the mod.

Any links? (but please, not from vape "gurus")

 

[Robert Cromwell]

I do not know for sure about the resting after discharge and charge either. But makes a bit of sense to me if using in high current drain applications.
I always wondered about the "pass thru" charging while vaping thing on mods. ok charging at 1 amp, pull 20 amps for 5 seconds vaping then back to a 1amp charge? repeat 15 seconds later, etc till battery dies due to more being drawn than being put back in? How can that be good for a battery?

 

[Mooch]

I am sorry, I asked about "dangers" of aging battery. Not about all dangers of li-ion battery.

I've never seen that information available on its own as a separate document. It comes wrapped together with other dangers and has to be dug out of the documents.

But, just by knowing that a cell's internal resistance increases, and its capacity decreases, over time you can figure out how that could be a problem. The increased resistance causes more heating unless discharge current levels are lowered, leading to any of the problems that excesive temperatures could cause. The decreased capacity could cause overdischarging and additional damage to the cell. But this would be noticed by vapers before overdischarge so I don't see that as realistic a problem for vapers.

Is rising internal resistance a danger waiting to jump all vapers who don't toss their cells by a certain time? No. For us the performance of a battery may drop down so far before the internal resistance increase could cause a problem that we always end up tossing the battery before anything could happen. But that doesn't mean that the risk hasn't increased at all.

 

[Robert Cromwell]

I've never seen that information available on its own as a separate document. It comes wrapped together with other dangers and has to be dug out of the documents.

But, just by knowing that a cell's internal resistance increases, and its capacity decreases, over time you can figure out how that could be a problem. The increased resistance causes more heating unless discharge current levels are lowered, leading to any of the problems that excesive temperatures could cause. The decreased capacity could cause overdischarging and additional damage to the cell. But this would be noticed by vapers before overdischarge so I don't see that as realistic a problem for vapers.

Is rising internal resistance a danger waiting to jump all vapers who don't toss their cells by a certain time? No. For us the performance of a battery may drop down so far before the internal resistance increase could cause a problem that we always end up tossing the battery before anything could happen. But that doesn't mean that the risk hasn't increased at all.

A good reason to never run batteries too close to their maximum rated discharge rate.

 

[suprtrkr]

Any links? (but please, not from vape "gurus")

Lol, no links. I am not a EE, but I know a few, and this is their advice. I do know enough about the chemistry of Li batteries to know heat is what kills them and therefore keeping them cool is a good idea; and enough to know the electrochemical processes inside the batteries are not instantaneous.

 

[Mooch]

You know, I tried to find an answer to my question, and the only reference I've got was related to testing a battery, so they like to rest a battery to have a more repeatable results. And nothing about degradation of a battery due to use immediate after charging. But I may miss something, who knows...

Wasn't there a memtion of temperature being the cause of degradation? A battery is often warm, at least, off the charger. And its internal temperature is higher than its external temoerature. Putting it to use immediately will cause its temperature to rise higher than it otherwise would, accelerating the normal degradation that occurs with every cycle.

 

[Alien Traveler]

Lol, no links. I am not a EE, but I know a few, and this is their advice. I do know enough about the chemistry of Li batteries to know heat is what kills them and therefore keeping them cool is a good idea; and enough to know the electrochemical processes inside the batteries are not instantaneous.

Sure, cool battery is much better than hot battery. But it has nothing in common with using a battery straight from a charger (if it was not heated in it). But battery can became warm in a mod quit soon, so does slight temperature rise due to charging really matter?

 

[suprtrkr]

Sure, cool battery is much better than hot battery. But it has nothing in common with using a battery straight from a charger (if it was not heated in it). But battery can became warm in a mod quit soon, so does slight temperature rise due to charging really matter?

Do you think it's possible to charge a battery without heating it? Or discharge one without heating it? I can agree we're not talking about a huge difference. A tootle Puffer might not notice. But a mekkie might.

 

[Mooch]

Sure, cool battery is much better than hot battery. But it has nothing in common with using a battery straight from a charger (if it was not heated in it). But battery can became warm in a mod quit soon, so does slight temperature rise due to charging really matter?

In my personal opinion, as long as the battery is just a bit warm...no. Not to any practical extent that we'll ever see.

If the battery comes off the charger at 35°C (versus 20°C if left to rest), and its use in a mod increases its temp by 50°C then we have a 85°C battery temp versus a 70°C temp. On paper, yea, that higher temperature means more damage. For us vapers I think that difference is tiny though compared to all the other abuse we put our batteries through.

If the battery comes off the charger very warm or hot then there could be problems if the battery was being used at its max limits in a mod. I think that's the biggest reason why there is a general warning to always let the battery rest after charging. There's always going to be someone who charges a battery too quickly and then tries to fire a 0.05 ohm build with it.

[edit] There are changes that are still taking place inside a cell after a charge finishes, e.g., the ions are still redistributing themselves equally across the cell. While I cannot see it helping a cell by using it immediately, I do not know how much doing this would accelerate aging. I do not know if these changes are completed when the cell comes back down to room temperature or not.