This weekend I was lying in the sun listening to music when half-way through a song it cut out. Aaaaaaaaaaaaaaaaaaargh! I absolutely can't stand music suddenly cutting off - it actually hurts. Anyway, that made me annoyed enough that I decided to do something about it.

The result was the Big Black Battery Box. No pics yet, sorry - will add them later. Picture if you will a large black project box with a shiny silver switch and the female end of a USB extension cable (one of those useless 10cm ones that come with USB thumb drives) sticking out of one of the ends. This box contains holders for two sets of 6 AA batteries in parallel and a rather over-sized 5V regulator (7805K). The switch connects the two sets of batteries to the regulator so that it doesn't drain power while sitting idle. This means that I can now carry around a _lot_ of power (5000mAh @5V) in a portable box that can charge USB devices. It can work with only 6 batteries or the full 12 for a longer time. It was planned assuming a battery voltage of 1.2V so it can use rechargeables and be environmentally friendly.

The disadvantage is that you need a screwdriver to change the batteries. Don't think that's going to seriously take off any time soon but should be fine for me. If only my music player could play while connected to the charger...