I was talking with a colleague about a project he is working on, specifically it's power supply...in this case a single Li-Ion cell. he was telling me that Li-Ion cells only have about 60% of the rated capacity. I completely disagree with this on so many levels as it is my understanding that you should store Li-Ion cells at 60% of their rated charge, but if one is getting only 60% of the rated capacity then one is buying defective, or mis-marked cells, and that it would be foolish for a manufacturer to mark a cell higher than it actually is. My colleague seems un-deterred though.
Upon inspecting one of the cells he sent me it says "Tenergy" on the side and 1400mAh, and the heatshrink around the cell looks the same as what I see on the website, but a good copy can be hard to spot.
I have not taken the time to do any testing on it, but I do wonder if the cell is an Ebay special. I have been using "Turnigy" packs I purchased from Hobby King with a rating of 2.0Ah/3.7v and the runtime I am getting matched my calculations pretty well.
I am thinking the cell is defective, or counterfeit.
So the question is what would be considered an acceptable tolerance for actual capacity compared to rated capacity on the cell? I would say 10% to 95%, but I think that's being generous.
Thoughts on this welcome.