This is the Olympus BLM-5 Lithium-Ion Rechargeable Battery. Small and lightweight, Lithium-Ion batteries can be charged or discharged at any time without developing memory effects. It must be noted that this battery can only be charged in the Lithium-Ion Battery Charger (BCM-5). This battery replaces the BLM-01 battery. However, it cannot be charged in the Li-Ion Battery Charger BCM-01
With an additional BLM-5 you will never miss a shoot caused by an empty battery. Perfect for longer shootings or portrait shooting with the HLD-4. The powerful lithium-ion battery BLM-5 has a capacity of 1620mAh and can be recharged about 500 times (by Olympus measurement). The Lithium Ion battery is rated at 1620mAh providing hundreds of shots between charges.