We have developed the swollen battery on our Acer C720 Chromebooks. We own over 100 of these devices and now have 25 with this swollen battery. I contacted Acer support to which I was transferred about five times. They are unwilling to do anything for us. The solution that they gave me was to send the device back to Acer for a $140 repair. That makes zero sense for a school district. I realize these things are out of warranty and I am asking not complete replacement, but I believe that Acer should accept some responsibility for this problem. It is obviously widespread and a defect from Acer's battery. I even asked about purchasing replacement batteries from Acer to which I was told that was not an option.
We will not purchase any more chromebooks from Acer if this is the support that we will receive. At no point in time can you expect school districts to continue to use batteries that are swollen with gas and in danger of explosion. You also cannot expect a school district to pay $140 to repair a device that cost $200 three years ago.
If you are thinking of purchasing the a new chromebook from Acer, I would look elsewhere!