The downside of internal batteries is if you are out of juice you can’t pick up a pack of double AA batteries to power up your PSP. Thanko has a creative solution to this problem found in their Rare Mono Shop, a bracelet that provides instant power to a Nintendo DS Lite or PSP.
Their charger bracelet can keep a PSP going for around 4 hours. Nintendo DS owners get much more juice, up to 22.5 hours on low brightness and at around 7.5 hours at high brightness. The charger bracelet has a cable with an interchangeable tip that allows it to work with both handhelds and a number of other portable electronics. I suppose being multifunctional might make the 4,980 yen ($48) price tag more acceptable.
However, to get any use out of the charge bracelet you have to remember to charge it in a USB port, carry around the correct tip and wear it.
Images courtesy of Thanko.