If the issues do not occur while plugged in, temperatures are decent, and only seem to occur at the same battery level, then I believe the issue to be the battery. Fortunately, as this machine is not a tightly built ultra-book, accessing the battery should not be extremely difficult. If you're feeling up to it, you may consider just purchasing another battery. A quick Google search brought me here: http://www.acerlaptopbattery.co.uk/acer-aspire-e5-475g-battery.htm