From the Motorola Website:
Things you should know about charging your battery.
New batteries are not fully charged. Plug the battery charger into your phone and an electrical outlet. Your phone might take several seconds to start charging the battery.
It may take several charging cycles for your battery to reach optimum performance.
The battery charger shipped with this device is a high rate charger specifically designed for your DROID.
Other chargers might take longer to charge your battery, cause your calls to fail during charging, or cause your phone to continuously power cycle.
You can charge your phone via USB cable but this charging time will vary based on computer specifications.
If battery is low, your phone will not immediately power up when you connect it to a computer via USB. Depending on how low the battery is, it may take up to 30 minutes for the phone to get enough power to powerup.
There are two built in tools to assist you in optimizing battery life.
1. Power control widget
The Power Control Widget gives you a quick snapshot of some of the tools that may be draining your battery. The widget provides information on Wi-Fi, Bluetooth, Location (GPS), Synchronization, and Display
To add the Power control widget:
From the home screen, touch Menu > Add > Widgets > Power Control
2. Battery Use Feature
The Battery Use feature provides you with a real time view of what features or applications are using the highest percentage of your battery. It also provides tips on modifying these features or applications.
To access Battery Use:
From the home screen, touch Menu > Settings > About Phone > Battery use
Tips to extend battery life:
Select a shorter backlight duration
Lower the display brightness
Use the AC adapter to charge your phone whenever possible
Turn Bluetooth off when not in use
Turn Wi-Fi off when not in use
Close any third party applications running in the background
Playing music, videos and viewing images in your phone will affect your battery life.
General Battery use & safety
Motorola recommends you always use Motorola-branded batteries and chargers. The warranty does not cover damage caused by non-Motorola batteries and/or chargers.
Caution: Use of an unqualified battery or charger may present a risk of fire, explosion, leakage, or other hazard. Improper battery use, or use of a damaged battery, may result in a fire, explosion, or other hazard.
Your battery can be charged without it being fully depleted, and can be charged every day if desired.
Battery usage by children should be supervised.
Important: Motorola mobile devices are designed to work best with qualified batteries. If you see a message on your display such as Invalid Battery, Invalid Charger or Unable to Charge, take the following steps:
Remove the battery and inspect it to confirm that it bears a Motorola "Original Equipment" hologram;
If there is no hologram, the battery is not a qualified battery
If there is a hologram, replace the battery and retry charging it
If the message remains, contact a Motorola Authorized Service Center
New batteries or batteries stored for a long time may take more time to charge.
Charging precautions: When charging your battery, keep it near room temperature. Never expose batteries to temperatures below 0°C (32°F) or above 45°C (113°F) when charging. Always take your mobile device with you when you leave your vehicle
When storing your battery, keep it in a cool, dry place.
It is normal over time for battery life to decrease, and for the battery to exhibit shorter runtime between charges or require more frequent or longer charging times. Motorola batteries are designed to last between 350-700 charge/discharge cycles at room temperature. This amounts to approximately a year to a year and a half of battery use for most people.
Avoid damage to battery and mobile device. Do not disassemble, open, crush, bend, deform, puncture, shred, or submerge the battery or mobile device. Avoid dropping the battery or mobile device, especially on a hard surface. If your battery or mobile device has been subjected to such damage, take it to a local service center before using. Do not attempt to dry it with an appliance or heat source, such as a hair dryer or microwave oven.
Use care when handling a charged battery-particularly when placing it inside a pocket, purse, or other container with metal objects. Contact with metal objects (such as jewelry, keys, beaded chains) could complete an electrical circuit (short circuit), causing the battery to become very hot, which could cause damage or injury.