Asus Eee PC T91MT dissected: the battery can be replaced
Unlike most Asus netbooks, the Asus Eee PC T91MT and Eee PC 1008HA have batteries that are not user replaceable. Most netbooks have batteries that slide out of the back or bottom of the computer. But these models are thin, light, and hide the batteries away inside the case making it much more difficult to remove or replace the batteries. That can be a problem if you want longer battery life or if your battery is defective or old.
But MyT91.info determined that if you go through the trouble of actually taking an Asus Eee PC T91MT apart (and it is apparently a lot of trouble), you can actually remove the battery fairly easily. Finding a replacement battery, on the other hand, might be a bit more difficult. Apparently there’s also an antenna missing which may affect 802.11n WiFi performance.
The web site has detailed instructions for disassembling the touchscreen netbook. Keep in mind, doing so will void your warranty. So if you really need the battery replaced and don’t want to risk doing some serious damage to the laptop, you might just want to contact Asus to see if you can send the netbook in for repair.