A new ASUS 90-NHJ9B1000Z battery comes in a discharged condition and must be charged before use (refer to the devices manual for charging instructions). Upon initial use (or after a prolonged storage period) the ASUS 90-NHJ9B1000Z may require three to four charge/discharge cycles before achieving maximum capacity. New ASUS 90-NHJ9B1000Z battery needs to be fully charged and discharged (cycled) a few times before it can condition to full capacity. Rechargeable batteries undergo self-discharging when left unused. Always store a battery pack in a fully charged staged for storage.When charging the ASUS 90-NHJ9B1000Z battery for the first time the device may indicate that charging is complete after just 10 or 15 minutes. This is a normal phenomenon with rechargeable batteries. Remove the batteries from the device, reinsert it and repeat the charging procedure.
It is important to condition (fully discharge and then fully charge) the ASUS 90-NHJ9B1000Z battery every two to three weeks. Failure to do so may significantly shorten the battery's life (this does not apply to Li-ion batteries, which do not require conditioning). To discharge, simply run the device under the battery's power until it shuts down or until you get a low battery warning. Then recharge the battery as instructed in the user's manual. If the battery will not be in use for a month or longer, it is recommended that ASUS 90-NHJ9B1000Z battery be removed from the device and stored in a cool, dry, clean place.
Invest in a good charger for your device. Ni-MH batteries should not be charged in a NiCad charger, unless the charger is specifically made for both chemistries. There are cheap chargers and there are expensive chargers. Make sure the charger you get has good reviews and is well made. Chargers with micro-controller chips are usually the best choice of your device.
Be sure to store your battery properly. Do not leave your batteries in a hot car, or in humid conditions. The best storage conditions are a cool, dry place. The refrigerator is fine if you stick in a packet of silica gel with your ASUS 90-NHJ9B1000Z battery in a sealed bag to keep them dry. It is a good idea to charge your NiCad or Ni-MH batteries fully before use if they have been in storage.