Q: Why is charging of Motorola phones so slow on the travel charger?

A: The standard travel charger packaged by Motorola with many current
phones puts out insufficient power for fastest possible charging and for
continuous use while charging.

For example, charger SSW-0509 for the V551 puts out only 375 mA.  The
V551 detects this as a slow charger, and thus keeps the external display
backlight off during charging.  Worse, there's not enough current to
keep up with use of the phone while charging, so while the phone is use,
the battery will still be discharged even with the phone on the charger.
With a fast charger the external display backlight is on during
charging, and the phone can be used while the battery is charging.

Motorola makes fast 1500 mA chargers that are compatible with these phones:
* SPN4716* (where * might be "B" or "C"), also known as
* NNTN4250 (nominally for Nextel, but also works with non-Nextel phones).
These chargers are readily available from dealers and on eBay for under
$15 (plus shipping).

(For what it's worth, Motorola probably saved less than $1 in cost by
packaging slow chargers instead of fast chargers with these phones.)