Answer to "Flickering when running on battery at about 65pct"Weak battery, back light will begin to fail. The X555LA models were known for this after about 2 years of use. Change screen out if you want to, however this will return in a couple of years. Just change battery every 3 to 4 for years, they do go bad under heavy use. Use the power settings to conserve battery and screen. Hope this helps.