&gt; One thing I miss in default raspberry pi is battery support. Today I just use the filesystem in RO.<p>It would be easy to put a battery + charging circuit in front. If you still want to power it through USB you could get increased efficiency by bypassing the DC-DC converter (just cut the trace from it and solder the output from your own PSU there).<p>If the RPi itself had a charging circuit, they would have to decide for the end-users what kind of battery chemistry, charge rate etc. it should support, and they would not be able to please everyone as these things are used for so many different purposes.