Specifications: Battery capacity: ≤3800mAH Maximum discharge current: 1.8A No-load output voltage: 5.1V ± 0.1V Standard charging current/voltage: 1.0A/5.0V Cut-off voltage of fully charging the Li-ion battery: 4.18V - 4.2V Package Included: 1 unit Lithium Battery Expansion board (without lithium battery) 4 unit copper standoff with screws and nuts. No warranty for USB cables, wires, electronic components such as switches, diodes, capacitors and others. Return is strictly only for products: a) Not function due to manufacturing defect b) Delivery error No Return for : 1) Abuse & misuse of the products 2) Doing activities that causing damage to the products, intentionally or unintentionally 3) Products has been modified & normal wear and tear 4) Incomplete items in original packaging