I recently decided to reinstate my netbook. I'll write about that another time, but just to say for now that the netbook is a very compact laptop. I bought it some years ago, and although it doesn't have all the bells and whistles I like, it's great for writing when you're on the move.
Anyway, I stopped using it because the battery died, in that it wouldn't retain any charge at all. Despite buying a new battery, I was unable to get more than an hour or so, if that, between charges.
But yesterday, I had the idea of doing what I do with my phone: switched off the wi-fi. I also made sure I didn't have more than one application open at a time. So far, it seems to be doing very well, and I am hopeful of getting a few hours out of the charge. Time will tell, but I feel confident enough to suggest that turning off the wi-fi is a very quick and easy way of extending the time between charges. I can also say from experience that this solution works for laptops and phones as well.
I believe the reason is that when the wi-fi is on, the device continuously looks for a signal, and that uses up the charge. So, when you're not using the wi-fi, switch it off.
You'll end up with more writing time!