For like 3 hours and can't find answers lol There are a multitude of things that I keep reading that I don't understand. Of course, after 3 hours I'm having trouble keeping everything in order. Someone help me with these things...I'll add more as I remember/run across them again....
Dripping
LR
Differences in 510's, 901's, 186xx something or another lol, carto's. Sorry, the mouse over feature doesn't work on some of these terms I'm unfamiliar with and all my searches produce posts that have these terms in them, but none that explain them to me lol
Spend as much time as you're willing to here:
The ECF Library - E-Cigarette Forum
And you'll pick up a lot of great answers.
Dripping: directly dripping 2-3 drops on your atomizer rather than using filled cartridges. 2-3 drops, at least with 510 and RN4081 atomizers, is about equivalent to a cigarette depending on your nicotine level and is just the right amount of liquid to give good vapor without "flooding" the atomizer, aka filling it with so much liquid that it can effectively heat up and produce good vapor. I "direct drip" almost exclusively and enjoy the vapor and taste moreso than with cartridges.
LR = low resistance atomizer. This typically means that the atomizer has a resistance of less than 2 ohms, ideally around 1.5-1.7. Low resistance atomizers should only be used on standard 3.7 volt batteries or 3.7 volt "battery mods."
They draw more power from the battery and produce hotter vapor, and ideally more vapor, than a normal atomizers. Some liquids taste batter with low resistance (or high voltage) while others may lose some of their flavor. Joye Brand 510 atomizers run at around 2.0 ohms if I recall correctly, but I've never used one. I'm happy with the generic 510 atomizers I get from TastyVapor and seem to favor them over the LR atomizers I bought from TotallyWicked. Low resistance atomizers tend to have a shorter lifespan and in my experience they can easily develop a "burnt" taste that I have trouble eliminating. Also, low resistance atomizers can wear down a normal e-cig battery's lifespan, even the bigger eGo/Tornado/Riva style batteries, because they draw power more quickly than the batteries are designed to provide.
"510" and "901" represent different types of atomizers. 510s have a reputation of being a good all-around atomizers designed for "mini" e-cigarettes which typically come with a push-button manual battery, and are also employed in larger-battery e-cigs like the eGo, Tornado, Riva, and Hello 016.
I haven't used a 901; I believe it's a "pen-style" atomizer designed for larger "pen-style" e-cigarettes and produces more abundant and cooler vapor than a 510. It's a matter of preference: there are many atomizers out there, produced by many different manufacturers. Each one has different characteristics and different battery-thread connectors, but you can often find adapters that let you use an atomizer on batteries it was not intended for.
I use 510 and RN4081 atomizers and have adapters that let me use the RN4081 atomizer on a 510 battery.
"186XX...," well I know that 18650 batteries are often used in 3.7 volt battery mods. They typically last very long due to a high mAh (milliamp-hour) rating, which is often exaggerated but still far beyond the "large battery e-cigs" like the eGo, and are able to produce a continuous high voltage without dropping down as rapidly as other batteries. Battery mods also typically deliver a higher voltage "under load" (while being actually used) than standard e-cig batteries.
"Cartos" aka "cartomizers" are devices which combine an atomizer and cartridge into a single piece. These are intended to be disposable, as in, you can refill them a few times, but they don't last as long as a typical atomizer. Some people prefer these very much because they can be economical and can store a lot of e-liquid. Others don't like them so much. Another matter of preference, people who hate direct dripping and standard atomizer+cartridge setups hopefully won't hate cartomizers and will be very happy with them
There are various cartomizer designs out there, including 510-compatible models. I don't know much about the KR808 and the various variations on it, but it's basically the "gold standard" cartomizer + battery two-piece e-cigarette out there.