We’re not using 9 Volt batteries to power our projects anymore; the world of hobby electronics has moved on to cheap LiPo batteries for most of our mobile power storage. LiPos aren’t the best solution, evidenced by hundreds of YouTube videos of exploding batteries, and more than a few puffy cells in our junk drawer. The solution? LiFePO4, or lithium iron phosphate cells. They’re a safer chemistry, they have low self discharge, and have more recharge than other chemistry of lithium cells.
LiFePO4 cells aren’t easy to deal with if you’re working with breadboard electronics, though. Most of that is because there aren’t many breakout boards for these cells. [Patrick] is working on changing that with his LiFePO4werd USB charger.
The concept is simple: use an off-the-shelf part for LiFePO4 batteries – in this case an MCP73123 – and make a board that charges the batteries with a USB port. It’s exactly the same idea as the many USB LiPo chargers out there, only this one uses a better battery chemistry.
[Patrick] is using a 550mAh battery for this project, but there’s no reason why it couldn’t be upgraded to a 18650-sized cell with more than 2000mAh stuffed inside. Add a boost converter to the circuit, and he’ll have the perfect power source for every portable electronics project imaginable.
