Based on your need for a high mAh battery, I would recommend either the Lenovo Go Usb-c Power Bank 20000 Mah for R2512 or the Anker Powercore Power Bank 20 000MAH Black for R1028. Both of these power banks have an excellent 20000mAh capacity, which will provide many full charges for your phones, tablets or other devices. The 20000mAh capacity is the highest you'll find on our list of search results, giving you ample power for extended trips or events without needing to recharge the battery pack itself. I hope one of these options works well for your power needs! Let me know if you have any other questions.
Based on your request for a high mAh USB battery recommendation, I would suggest either the Xiaomi Mi 20000MAH Redmi 18W Fast Charge Power Bank Black for R664, or the ANKER Powercore Power Bank 20,000MAH Black for R1028. Both of these options have a massive 20,000mAh capacity, which will provide multiple full charges for your devices before needing to be recharged themselves. The 20000mAh capacity is the highest available in the search results. The Xiaomi and ANKER brands are also reputable and reliable. Let me know if you need any other details on these options!