Markus Gritsch shared his LiFePO4 charger project in the forum:
Since I really like using LiFePO4 AA and AAA batteries in some of my projects, I finally gave in and built a dedicated charger for them.
Previously I used a lab power supply to mimic the constant current/constant voltage charging curve, which worked also fine. But after seeing Patrick Van Oosterwijck nifty LiFePO4wered/USB™, I thought it would be a bit more convenient to charge these batteries using USB.
LiFePO4 charger – [Link]