HP iPAQ h1910 Reference Manual page 30

Getting Acquainted
4. Re-install the battery cover by matching the tabs on the
battery cover to the latches on the iPAQ Pocket PC, then snap
into place.
The iPAQ Pocket PC will not operate if the battery cover is not
installed.
You will need to fully charge your iPAQ Pocket PC within the
next 12 hours. The amber charge light is flashing (blinking) when
your iPAQ Pocket PC is recharging the battery. The charge light
turns solid amber when the battery is fully charged.
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