The FCC published further documents of iPad, uncovering secret parts – including detailed interior shots of both the WLAN as the UMTS version of the iPad, as well as important product and warranty conditions. This opens up a good overview of the iPad-inside (which is dominated by the battery) and also some less, or even previously unknown details come to light. First of all battery, as stated by Apple is a lithium-polymer battery (3.75 V 24.8 Watt hours).
iFixit analyzed FCC documents and they find Apple Logic Board including A4-SoC and Flash memory from Toshiba. It also seems to have the same wireless Bluetooth / Wi-Fi combination of Broadcom to sit on iPad, same as third-generation iPod touch.