Here is a useful video to show you how the Acer Aspire e15 laptop battery is removed:
If your model does not have the release mechanism shown then it is the newer style and has a built-in battery which is made up of several individual battery cells - you will need to remove the cover off the back of the laptop to access it.
Please attach some photos so I can confirm.
Ok I'm sorry about that, is there anything else I can help you with today?
Ok, that is all then.
You have a nice day!