My Nokia n900 is not charging fully especially using the wall socket charger, i love this phone only this problem. thanks!

Whenever you need to charge your power chair or scooter get into the habit of charging overnight. The battery level indicator lights will tell you if your chair or scooter needs charging. Whenever the lights are down into the yellow and especially if they are in the red. If you have the off-board charger, plug the charger into the charger port in the front of your joystick and then plug the charger into the wall socket or turn the on/off switch on and let it charge overnight. When you get up in the morning the charger should have a red light(power) and a green light illuminated (indicating fully charged) Always turn the charger off or unplug it from the wall socket before you unplug it from the chair or scooter. Never have the power on to the charger when you plug or unplug it from your chair or scooter. Whenever you get new batteries always give your batteries a full charge before use and then if you use the chair daily charge it every night. If you do not use your chair or scooter daily charge it at least once a week. Never leave the charger plugged in and on for more than 24 hours. Your batteries should last you 3-4 years if you charge them correctly.