Ok so the people that have been reading my post know that Im new to the all the different mods that take batteries. Well I have a topbox nano, a joytech eviv vt, nebox, and a kanger drip box. They all take a single 18650 battery, I have 4 Samsung 25r and I have 2 Lg H2. Anyhow I ended up buying the nitecore D2 and I charged 2 of the Samsung and I have 1 in the nano and 1 and the evic and when the battery goes down a little bit I use the USB just to top it off. Well I keep hearing about all this decharging and it's kinda of scaring me. I have researched it and honestly I don't understand what the hell it's talking about. Can you please explain to me what how o need to charge and decharge these batteries correctly, because I thought I had it down. I originally bought a cheap little single 18650 charger and it sucked so I bought the nitecore ( I read the instructions, which we're pretty self explanatory) I'm not a beginner vapor it's been 4 years, and I really just need some help with these batteries so any info you have for me would be great.
Thanks so much
Maria
I'll add in to what the others have said,
@retired1 and
@dcfluegel both explained it well. Recharging when the battery has been drained only slightly and keeping it topped off at full charge all the time is a bit damaging, lithium batteries we use have a median working charge level at 3.6 to 3.7volts where they stay at that charge level the longest, 4.2v (full charge) down to about 3.9v is a gradual but quick discharge, 3.9 to 3.6v is a slower slope it can stay at for a few hours of moderate use, then 3.5 to 3.0v is an equal discharge slope a bit more rapid than the 4.2 to 3.9v slope, then 3.0 and further is a nose dive. Lowest minimum charge without drastically damaging the battery is 2.5v, which below this level, most chargers will not pull the battery back up to usable levels again, and only a highly specialized charger can do so, some Efest and Xtar chargers can do a rescue charge, but it is advisable to not run a battery below 3.0 to 3.2v. Most regulated mods have a battery low signal at about 3.5v, and a cut off at 3.0 to 3.2v the lowest I've seen, some of my mods, especially my higher powered mods, once below 50% charge I'll swap the batteries out for fresh ones, this is around 3.6 to 3.7v for myself and yet to have had any issues.
Yes the lower the battery charge level the higher the amp draw is on them is true, but most mods if the amps needed are above what the battery can provide at any given time, they will warn you as they detect a voltage sag from the battery saying battery under current warning or something to that affect, my Sigelei150watt does this at about 25% or lower charge at a setting above 50watts and won't fire at all giving a "Check Battery" warning.
Charging via the USB of your mod, single battery mods the chargers are a bit more reliable, but you do not want to burn out the port, so use it sparingly in emergencies only, especially the Evic VTC mini, the charge port is also the firmware upgrade port.
Unless you are firing very high wattage, you can run your batteries down in them to the point of the mod shuts down or gives a check battery warning, what is termed mod cut off voltage level, you are not damaging the batteries, as mentioned though above about charge cycles, most batteries have a 150 to 250 full charge cycle lifespan, I recharge at 3.6 to 3.7v (50% charge) which extends them out to about 300 to 500 half charge cycles of life span.
Storing batteries for long term, discharge them down to about 3.4 to 3.5v, this is factory shipping charge level and check their voltage with a Multimeter about every 6 months, they reach about 3.2v top them back up to 3.4 to 3.5v again where they can stay for a few years of no use, I do not keep batteries charged to 4.2v without use for more than a month.