Determines battery cell quality.
Not all ICR, INR, and IMR cells are created equal. This is where the supplier/manufacturer comes into play. There are quite a few different makers, some you can trust some you can’t. Will give a quick rundown of them and what makes them better.
AW- In terms of cells these are the highest quality available. Andrew Wang used to work for Panasonic, developed his own company, and is the top provider of cells to flashlight users (and of course now vapers). He gets the top 5%* of cells from Panasonic, Sanyo, etc. and puts his custom PCB on ICR cells. Cells routinely last 500 charges or more if handled properly.
Efest- Top 10% of cells from the same manufacturers as AW, though also gets cells from LG (top 15%) and Sony (top 15%). These do not last as long as as AW, but perform as well over the first 150 charges. Usually last 250-300 charges. As with the recent trend, another knock on Efest is their over stating of their amp limits on a lot of their high drain batteries.
LG- Top 10% of cells are sold as bare cells to consumers. The top 5% are reserved only for cars, phones, laptops. They have improved their cell quality and chemistry over time. Would put them one notch below AW, but right up there with the other big battery manufacturers.
Samsung- Usually only top 10% of cells are available to consumers. Top 5% are reserved for laptops, tools, and car companies. They specialize mainly in INR and ICR chemistry. Samsung cells out perform Sony, but due to INR still being in it’s infancy the cells do not last as long as their IMR brethren. This applies especially if using them in high amperage situations.
Sony- Usually only top 10% are available to consumers, though they have sold a few top 5% when a new cell (like the VCT4 or 5) first gets released. Average life span is usually 350-450 charges. The only issue with Sony is they have exaggerated amperage numbers on the VCT4 and 5, though not through fault of their own*10. Another good cell, one notch below AW or Panasonic.
Panasonic- Top 10% of cells are sold to consumers, save for hybrid IMR (like the 2900mAh) cells which are top 5%. These cells can last 400-500 charges*8, and are considered the next best cells to AW.
IMREN (formerly MNKE)- Top 10% are available to consumers, their top 5% are reserved for car companies only. Since IMREN bought out MNKE can no longer call them a top cell manufacturer. Not because they are no longer making good batteries, but because the bare cells sold to the public are grossly over inflated when it comes to their amp ratings.
Sanyo (owned by Panasonic)- Top 10% of cells available to consumers. Again ranks with Panasonic cells in quality. Last between 400-500 charges.
Trustfire- Uses top 20% of LG, top 20% of Panasonic, top 20% of Sanyo. These are considered cheaper cells, but still decent. Usually get 200-300 charges out of them. Trustfire is a re-labeler like efest and AW but uses lesser quality cells. Avoid if possible. Has been known to lie about capacity on certain cells.
Ultrafire- Uses cells that are under 20% from a number of manufacturers, or worse pulled cells of unknown origins. Infamous for using inflated mAh numbers, should be avoided at all costs.
Resource --
Beginner's Guide to Lithium Batteries (rev. 3 April 2015)