OK guys, so for future reference for all those who might come across this issue, it was indeed the battery. I put in a new one and the problem has gone away. I had to look around for a while, as the prices I was getting for the battery were exorbitant (as with everything else here in Canada, it seems
). Thankfully, I was able to find one at Telus mobility for a mere $20 and it did the job. Thanks to all who helped.