A brief comment about the picoUPS-100: It can run off 6-18V DC which at first seems pretty flexible. However, it can only charge the battery when supplied with at least 15V. While this may seem reasonable enough, the board does no conversion of its input voltage -- if input voltage is higher than battery voltage, it simply routes the input voltage directly to the UPS output. What this really means is that the devices you run off the UPS need to function with 15V, and they need to be able to handle voltage suddenly dropping to 12V as will happen when the UPS switches to battery power.