This is a known issue with the first generation Pebble watches. My PS had it and I had it replaced under warranty before Pebble folded.
None of the fixes worked for me. My replacement PS has been working fine, but the battery life has gone down from a solid 6 days to 4 days. So I decided to replace it with a Pebble Time Steel refurb I bought through Amazon for ~$80. I get a solid 7 days and sometimes 8 days out of this battery before it hits 10% remaining and I charge it.
I love the PTS. I'm not aware of any display issues the PT series have. So I only expect to see the battery decay over time. I'm very tempted to buy another PTS and store it for the day my current PTS battery bites the dust.