Battery issues

[Thatjeepguy]

When I purchased my drone I also bought a second battery. About a month after I owned the drone one of my batteries started to swell at the top and bottom of the battery. I purchased another battery to replace the bad one. Now both of my batteries are swelling like the old one. I only leave the batteries in the charger until they're fully charged and I store the drone in my bedroom closet.
Am I doing something wrong or has anybody else had this problem?

 

[Murray Martz]

When I purchased my drone I also bought a second battery. About a month after I owned the drone one of my batteries started to swell at the top and bottom of the battery. I purchased another battery to replace the bad one. Now both of my batteries are swelling like the old one. I only leave the batteries in the charger until they're fully charged and I store the drone in my bedroom closet.
Am I doing something wrong or has anybody else had this problem?

Although it is odd that they would have a problem being new in that short a period of time, even without out using proper storage, typically when not in use, the batteries should be stored a 50% capacity to avoid what is happening to yours. Again seems odd for such a new battery as I have had ones for the Typhoon H that were not discharged for months and still worked fine. Sometimes you get lucky like in my case(not suggested to follow my lead on leaving charged), and sometimes you don't as in your case. Could also be that you just got a bad battery. You may want to use a volt meter and check to see what you have in each cell for now and then post it here. I am not versed in the Mantis Q platform at all.