Battery Noob Important

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..  

Will I get longer battery life if I charge my batteries at .5 amps vs. 2 amps? I feel like I'm getting less battery life by charging them so quickly. Any info would be appreciated, thanks!  

my vaporizer has a battery of 2800 to
was charging on a 2a 5v charger
carried about 3 full charges.
so the manufacturer recommends a 1 to 5 v charger
tripled charging time instead of decreasing.
do I continue with 2a instead of 1 a?
can give problem ???
thanks  

So last night I guess I was more tired than I anticipated and forgot to unplug my charger before knocking out. I was charging a 18350 battery. As soon as I woke up I remembered and immediately unplugged the charger. I left the battery sitting all day and just checked it on my multimeter and it reads 4.18 volts. I also checked it on my sigelei and it read 4.2 volts. I am th overly cautious type though so I just wanted to ask you guys if you think the battery is still safe or if I should properly dispose of it.  

intstalled 2 sony vtc 5's in my new nitecore d2 that i just received today. both bays indicated low charge with 1 bar on each meter. 3.67v for bay 1 and 3.62v for bay 2. an hour later bay 1 has 3 bars, 3.88 v and bay 2 has 1 bar, 3.71v. seems bay 2 is not charging. is the charger or battery acting up?
after bay 1 finishes can i install the battery not charging in bay 1 to test.  

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.  

So I have (2) 3100mAh Efest batteries rated @ 20A and (1) 2500mAh Efest batterie rated @ 35A. I'm experiencing a pretty annoying problem with all 3 of them and that is they aren't lasting nearly as long as I feel they should be. I can EASILY vape through a battery in less than one hour while heavy vaping. I'm aware that I am sub-ohming and that requires more power from the battery but these are just going way too fast and something isn't right. I have a BEC Pro mod that takes a single 18650 battery and I'm vaping an Aspire Atlantis tank @ 35 watts with the .5 ohm coil installed. I charge each battery fully with a Nitecore i2 before using them and it'll say 4.2V on my mod & on my Smart BEC app it will say 100% as I take my first few puffs but then starts draining at a ridiculous rate until they are dead. I am not aware what the mod efficiency is on my BEC Pro or if there might be something not working properly within my device. Can someone please help me find what's wrong with these? Maybe some of you have eperienced this problem with Efest batteries in the past? Thanks in advance!

Edit: These are genuine Efest batteries as I bought them straight from the manufacture on Ebay.  

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 have the ipv4 on pre order (can't wait) im stuck on the battery choice. I want to find the best choice for a vv/ww mod. With the most mahmp life and amp draw load. I was thinking about the LG HE4 . 2500MAH 35A High drain. I heard the efest purple has great battery life. But I enjoy lower builds. .15-.2 occasional .1 . I just want the safest battery with the most load and lifespan. Anyone with some info plz enlighten me. We gotta stay safe. Thxx  

My charger has those eeh springy slides to keep batteries tightly set.
Couldn't find a respectable charger without them.

How do you avoid damaging the battery wrap when inserting/removing in a charger?

Inserting a battery is easier as you can preload the slide with a finger.
But when removing a battery the spring slide eats into the battery wrap on the way up.
Would be nice to avoid any wrap damage.

Maybe put a rubber band / twine / other (non-conductive) underneath so it can be pulled and open the spring slide after charging?
Like a slingshot
Other ideas?