The Li-ion polymer offers little or no energy gain over conventional Li‑ion systems; neither do the slim profile Li-ion systems meet the cycle life of the rugged 18560 cell. The cost-to-energy ration increases as the cell size decreases in thickness. Cost increases in the multiple of three to four compared to the 18650 cell are common on exotic slim battery designs.
If space permitted, the 18650 cell offers the most economical choice, both in terms of energy per weight and longevity. Applications for this cell are mobile computing and video cameras. Slimming down means thinner batteries. This, in turn, will make the cost of the portable power more expensive.
