Who I have the same questioned this topic

So I recently upgraded my plan from a (very) old one to a newer one with more data. I also purchased a battery extender since my phone was losing charge easily. Would either of those effect my signal strength or service? Every since changing those two things, my phones signal is barley there. Most of the time I lose signal all together.

Before I had great signal and service pretty much anywhere I went. Now, it's hard to find a place where my phone will even get a signal..

PLEASE HELP!!