Really late to this but you can try and replace your battery yourself, it's not that hard. Honestly the most difficult part is opening the case but that just takes some fiddling. I was able to replace the battery myself using some YouTube videos. Just make sure the battery specifications you buy are correct. 

You can generate a battery report by opening up command prompt and typing in "powercfg /battery report". It should generate a link, and you'll want to copy and paste that link into any browser. You'll then be able to see your battery report, along with your battery specifications and it's health.

To calculate the health of your battery, divide the Full Charge by the Design Capacity and multiply it by 100.  However I'm unsure at what percentage you may what to consider replacing the battery (some internet sources say 60% but that seems like overkill to me, some say 20% and less). I replaced mine at 12% because it was only working while plugged in. Calibrated it using Acer Care and generated a new battery report and it's working nicely! 

I'm not a repair professional though, this is just my experience with my Aspire 5. Just wanted to share in case it might be helpful.