Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
It sounds as if either internal power regulation, or an internal short, is defective in your PT4. Since it is within a year of its purchase, it may be covered by warranty provisions.
Let me know what brand the PT4 is, its maker name that is, and also whether you have the sales slip or other record of its purchase in July, and I will advise you further.
As for the GolfBuddy device - tell me its model #, and I can point you to the right battery replacement choice(s).
Let me know, by Reply To Expert, and I will help you further. Thanks.