... battery : 1, long lifespan 2, enviromental friendly 3, different material to choose 4, 18mmX65m 18650 Lithium iron ... DENSITY(W/kg)≥1140 RATED VOLTAGE(V) 3.2V ENERGY(Wh) 3.2 VOLUME DENSITY(W/L) ≥2400RATED CAPACITY ... ≤42 POWER DENSITY(W/kg) ≥1140RATED VOLTAGE(V) 3.8V ENERGY(Wh) 5.32 VOLUME DENSITY(W/L) ... ≤45 POWER DENSITY(W/kg) ≥1130RATED VOLTAGE(V) 3.6V ENERGY(Wh) 5.4 VOLUME DENSITY(W/L) ≥3090RATED ...