I'm seeing wildly varying capacities that are seemingly fake on 18650 cells, such as these "9,800 mAh" ones on eBay, but are ~$1 / cell.
However, 'genuine' cells from Panasonic and similar name brands seem to top out around 3,500 mAh or so, but cost more like $8 / cell.
How can I tell true capacity apart from the lies?
Best Answer
Obviously when you already have one in your hands, you can measure its true capacity.
However lets for a moment think about where these fake cells might come from:
In the first case you can be sure that the real capacity is on a much lower level.
In the second case the capacity is at most at the level of the best competitors on the market.
In conclusion: anything that is above the well established brand names is a blatant lie. Anything that is at their level might be a lie or could be true, no way to figure out than to measure it.