Is my 8320 dying, or my battery?

While I am ONLY in the middle of calls, never any time else, my 8320 will randomly just blink into dead nothingness. It's acts as if the phone just switched off; no warning, just immediately a blank screen, no sound, and a confused person on the other end of the call. I have to do a battery pull or plug it into a charger to get it to start to boot up again.

I would think it's just a battery that's having problems, but since it only happens while I am making a call, I'm not entirely sure.

Anyone have any insight for me?

Thanks.

Now it's sometimes blacks out during the hourglass startup screen after a previous blackout. Still works fine when plugged into my computer or the wall. I'm thinking it's a battery.

If anyone thinks differently, please let me know your opinion ASAP as currently I'm planning on going and spending $$ on a battery today, and if it's my phone I'd rather it not be a waste. :D

Mine would do that as well. If I was on a call, it would make some bad static noises before shutting off. In that case, yes it is the battery.