When To Charge 21700 Battery?

Now that I have gotten into unregulated mods I've been doing a lot of reading about batteries... well actually I had started reading before but now that I am actually using them I want to know more.

One thing I am a little puzzled about is that you should recharge a battery when it's about 2/3 discharged and you should never charge a battery that is completely discharged. My questions:

1. How do I know the level of discharge in my battery? - I don't own a multi meter
2. What do you do with a fully discharged battery? - just chuck it?  

Hi
I just got a Xtar VC2s charger for my 21700 batteries (Samsung 40T).
Chose that charger also because it "charges at safe low current".

When it charges 2 batteries, it's at about 1000 mAh for each battery. All good.
But when charging only one battery, it charges it at 2000 mAh. Hmm?

I assume 2000 mAh is still "safe".. But won't that reduce lifespan on the battery?

The charger manual says "when the power supply is insufficient, the charger will reduce the charge current correspondingly".
So maybe I should get a usb power supply with like 1000 mAh output?

I will only be charging one battery at a time, and prefer charging slowly if that gives more safety and lifespan.

But I don't know if charging at 2000 mAh is really an issue..  

Can I use an external battery pack to charge an IPV Mini?

I have a 10,000mAh external battery to charge my cell phone (Note 4, with a 3500mAh battery), which has 2 options for charging: 1.5v=1A and 2.5v=2.1A.

Is it recommended? Is it safe? Are there any precautions I need to take if I use the battery pack?

I haven't gotten around to getting an extra 18650 battery (and charger) for the IPV Mini. I've finally realized that it takes maybe 2-3 hours to charge the battery via the USB cable. But the one battery doesn't quite last me all day, depending on how heavy I'm using the Mini.

I usually carry a Volcano Inferno once the Mini dies, but the Volcano really sucks in comparison to the Mini. I'd love to be able to charge the Mini while I'm out and about.

I've added a pic of the external battery for specific information.


Thanks for all your help.  

I ordered a SXmini SL class with the sx485j chip and it recommends a 35a battery. I only use .15ohm coils at 60 watts so I should be good with a samsung 18650-35E right? Going to buy 21700 batteries once these start losing their charge because I just got them recently..  

I am looking for a dual 21700 mod. The available ones, I probably will buy but, there aren't many to choose from. There are several single 21700 mods. My question is how long (on average) will a single battery mod charge last (I know this question is subjective). I vape around 65 watts, most of the ones I have seen online are rated 100 watts. I do not want to leave home and my mod die out because it was a single battery mod. I know I could carry a spare charged battery around, I just do not want to have to. Thanks  

I have a variable voltage/wattage battery and I have heard that some say charge it as often as you can this reduces stress, others say that's bad, some say a combination of long and short cycles but I don't know which is best. My battery's manual said get down to 10% but it doesn't measure it accurately (but I love these batteries so I don't want to change but they are expensive so I want to prolong their life span as long as possible even if that does mean charging them very often.) I do have two so charging often isn't an inconvenience for me if that's what I am supposed to do.  

I'm not battery expert so I am not sure how everything works, but here are my concerns.

My Smok Thallo can charge at a 1.2A current but it is a USB-C, why include a USB-C if 5V/1.2A can charge as quickly with a Micro USB? I think.

So here is the question, can I charge my Smok Thallo with a 2.1A if I use the wire that came with the kit? It's hard finding a solid power bank with 5V/1A only. I cannot remove the battery, it has a built-in 3000mAH one.

Thanks!  

i have a new Itaste VV4 15 watt 1000mah
I don't seem to get as much time out of my battery as i expected- does anyone know about how long it should last?

I'm going to test it out to see exactly how much time i get out of a full charge but as of right now i just feel like it's not lasting as long as it should.

Also when I use it plugged up on a charging cord the battery still runs out till it eventually has no charge and turns off and cant be used till it adds up some charge on it- I thought since it was a pass through device i would still be able to continue to use it while being plugged up on the charger, so im not sure if I should actually be able to with this device and mine is not working correctly or thats just how this unit does work.  

Is it ok for the battery if I keep charging it when it reaches half way or 2/3rds left? Or is it usually recommended to fully discharge and then charge it all the way. Device I'm using is an rdna 40.  

I ordered two of these batteries from FastTech. The cheap price and high capacity (without having a mod or some awkward huge battery) attracted me to them. Some two weeks later they show up...

I have two Puff King chargers that came with starter kits we bought at a B&M store. We've been using them with Tripl3 eGo batteries, one Puff King battery (and another Puff King battery, which was taken back and exchanged for another eGo-T battery, which broke), and so far no problems screwing any batteries in. These two from FT show up however and neither will screw into one Puff King charger, but they both did into the other (same charger, down to the model number and everything). Now, one battery from FT still screws in, but the other doesn't.

I took the non screwing in battery to a local B&M store and the guy there was able to screw it into one of their chargers. He handed it to me, and I unscrewed it, screwed it back in, unscrewed it again, and then neither of us could screw it in again. Now I have one battery from FT that will screw into one of my chargers, but not the other. The other battery will charge, but it has to just like sit in the charger and hope the connection stays okay for it to charge. I still have no problems screwing any of my other batteries into either charger, just these ones from FT. Also, it's worth mentioning that the FT batteries never seemed to screw in right... it always felt weird and finicky getting it to go in.

What's up with these batteries? They claim to be eGo/510 threaded, just like my other batteries. They look just like my other batteries too, except they won't screw in right...