mophie’s power boost battery contains a large 20,000mAh internal battery. Plus, the power boost portable battery features multiple USB ports so you can charge multiple devices simultaneously. A versatile USB-C port means you can charge a device then recharge the power boost from that same port. Slip it in your bag and stay powered through the day with up to 4 full phone charges.**Number of charge cycles are estimates based on salculations using total Power Boost capacity and estimated wired charging efficiency to a standard iPhone 15 Pro. A single charge represents charging a default iPhone 15 Pro with the default settings from 1% to 100% state of charge.