Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
I don't think you can return just the battery. Besides, you really need at-least two. I had 6 before I started buying the new ones and found myself running out of juice on occasion.
People swear by the ocotominer boards, but I like more cpu and prefer to keep my rigs to 6 gpus. Right now I'm running these https://www.newegg.com/p/N82E16813145016?Item=9SIARTEFNN7753, but they use 6-7th gen CPUs. Super easy to setup and they've been solid.
I just ordered one of these...