I was thinking of, how to charge batteries of Alfred. Suddenly I have realized that my old and probably dead computers psu can help me. If you think it supplies constant 12 volt for long long time. Maybe i can tune it make it work for Alfred for some time also. These batteries have 6 cells, each are 2.2 volt meaning fully charged battery will be around 13.2 volt. So I may need to modify the power supply a bit.