If you just charged your EEE, but the battery indicator hasn't gone up at all, reboot and it'll read correctly. This is possibly a problem with the ACPI driver.
I've found that if you cat the battery info this seems to cuase the battery charge state to be refreshed:
i think its the ACPI driver that needs to be improved. another thing is, once the monitor reaches 7%, the low power prompt will come on. but i
realise that i can still use the laptop for quite some time more without the % dropping. this means that the battery reporting is not accurate, and
even if it reports 7%, there might still be more juice than reported by the battery monitor.
(note: there are more threads on this particular issue, please add them if you find them)