DIY 20,000mAh Power Bank - Was it worth it? In this blog post, I embarked on a fun project to create a DIY power bank using two 10,000mAh lithium cells I had lying around, and a charge control board. After some tinkering and tests, I learned that measuring power bank efficiency requires more than looking at amp-hours. With some help from a friend, I found out our power bank was actually over 93% efficient, a pretty fantastic result. Despite some challenges with certain devices not drawing their full potential power from my power bank, I concluded that while it was an enjoyable project, buying a ready-made power bank might... 15 February 2023