May be this - for me successful - listing of steps for solution to my recent problem will help someone...
My 2017 15inch TB MBP started around 2 weeks ago loosing ~15% of battery power over night, while sleeping. It did not use to do it. My prior experience is, that this 2017 (and prior 2013 & 2009) 15 inch MBPs loose 0-3% of battery power over night while sleeping. My suspicion is, that 0-3% is about the precision of the value anyway.
System is on the latest Catalina (10.15.4) but this change did not coincide with the upgrade. It took me few days to go through various steps below, but problem was solved without any disruption to my use. Here are steps I did, so you can try them also, if needed.
1. Disabled wakeup by Bluetooth devices. (May be my mouse was waking it up?). No change.
2. Reset Catalina "energy saver" settings in System preferences GUI (or use "sudo pmset restoredefaults" in command line). May be power management setting got somehow corrupted? No change.
3. Used pmset command and checked various settings, nothing seemed to be obviously wrong (I have records to my prior pmset settings). No change.
4. Used pmset command to identify, if my computer is sleeping over night and when it is being woken up and why (pmset -g log immediately after waking up will display list of recent events). Logs showed, that computer was sleeping, awaken every ~2 hours or so and was active for ~20 seconds each time. This is correct behavior.
5. Interesting observation I made was, that my iStat Menus was recording each time computer woke up the battery levels and those were dropping in between the awake times. I lost 2-3 % of battery for every ~2 hours while system was sleeping (as pmset logs told me)... That pointed to SMC controller, since that is what controls behavior when system is sleeping.
6. Discharged battery to ~20% and recharged again. Cannot hurt to do this once in a while. No change.
7. Located Apple instructions for my computer to reset SMC and NVRAM (may vary slightly by computer type) and went through those steps. Interesting note - booting to recovery mode takes surprisingly long time... Problem solved. After overnight sleep, my battery stayed at ~100%.
Cannot guarantee this will help. May not, especially if the problem is with system or hardware. But it is listing of steps, based on this and other discussions, which can help identify problem and may be even provide solution. Starting from painless steps and going towards more painful. Command pmset in Terminal.app is extremely useful, use command "man pmset" in Terminal.app to get manual.
My next step would be reinstall system in place and if that would not help, then take it to Genius bar. In my case it is easy, I have Apple care so let Apple deal with complicated issues.
My 2017 15inch TB MBP started around 2 weeks ago loosing ~15% of battery power over night, while sleeping. It did not use to do it. My prior experience is, that this 2017 (and prior 2013 & 2009) 15 inch MBPs loose 0-3% of battery power over night while sleeping. My suspicion is, that 0-3% is about the precision of the value anyway.
System is on the latest Catalina (10.15.4) but this change did not coincide with the upgrade. It took me few days to go through various steps below, but problem was solved without any disruption to my use. Here are steps I did, so you can try them also, if needed.
1. Disabled wakeup by Bluetooth devices. (May be my mouse was waking it up?). No change.
2. Reset Catalina "energy saver" settings in System preferences GUI (or use "sudo pmset restoredefaults" in command line). May be power management setting got somehow corrupted? No change.
3. Used pmset command and checked various settings, nothing seemed to be obviously wrong (I have records to my prior pmset settings). No change.
4. Used pmset command to identify, if my computer is sleeping over night and when it is being woken up and why (pmset -g log immediately after waking up will display list of recent events). Logs showed, that computer was sleeping, awaken every ~2 hours or so and was active for ~20 seconds each time. This is correct behavior.
5. Interesting observation I made was, that my iStat Menus was recording each time computer woke up the battery levels and those were dropping in between the awake times. I lost 2-3 % of battery for every ~2 hours while system was sleeping (as pmset logs told me)... That pointed to SMC controller, since that is what controls behavior when system is sleeping.
6. Discharged battery to ~20% and recharged again. Cannot hurt to do this once in a while. No change.
7. Located Apple instructions for my computer to reset SMC and NVRAM (may vary slightly by computer type) and went through those steps. Interesting note - booting to recovery mode takes surprisingly long time... Problem solved. After overnight sleep, my battery stayed at ~100%.
Cannot guarantee this will help. May not, especially if the problem is with system or hardware. But it is listing of steps, based on this and other discussions, which can help identify problem and may be even provide solution. Starting from painless steps and going towards more painful. Command pmset in Terminal.app is extremely useful, use command "man pmset" in Terminal.app to get manual.
My next step would be reinstall system in place and if that would not help, then take it to Genius bar. In my case it is easy, I have Apple care so let Apple deal with complicated issues.
