To reach the 12 hours the battery would be in prime condition as well as the WiFi and such turned off.
-> BATTERY SAVER is to extend the battery life at the expense of how many minutes you get on a charge. Many folk misunderstand that so to get the longest run time you do not use the battery life saver.
i just bought an Acer Aspire E5-575G-53VG, off of ebay it was like new and works really well the only problem is that it says its so posed to have 12 hours of battery life, but i can only get mine to last a max of 3 hours with battery saver and the screen fully dimmed. if anyone can help that would be great.

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