So I really like my base model gold macbook so far minus one nagging issue that seems to have no resolution. I am open to suggestions and will list below the few things I have tried. Issue: rMB looses 40-50% charge overnight (10 hours between use) while off of the charger and in sleep mode. This is odd as while it is under heavy use I can get a solid 8 hours of battery with the screen on. Something odd is happening with the screen off that I can not resolve causing huge battery drains. Things I have tried with no success: - Day 1 Restore rMB and set up as new - Day 2 Close all apps before putting to sleep - Day 2 Check activity monitor for apps preventing sleep (none) - Day 3 Try the newest beta for El Cap - Day 4 Turn off location, bluetooth and wireless before putting to sleep - Day 4 Look for "idle wake processes", discovered kernel_task if fairly active however no more so than on my neighbors iMac... - Day 5 Restore to Yosemite and set up as new, installing no apps - Day 6 Called apple support, explained issue and was instructed to run a hardware diagnostic. No issues found. Checked battery health and all is normal. They asked me to check for updates, there were none. Was told to bring it to store for analysis. - Day 7 took to apple store, the suggestion was to allow them to keep it for several days for testing. This is not a viable option at this time as I am wrapping up 2 summer online courses and need the rMB as it is my main computing device. Any ideas would be greatly appreciated and thank you in advance. RESOLVED: Called apple again today to see if I could get a senior advisor. I was very fortunate to speak with a very knowledgeable young lady, Lynn. She was able to solve the issue in a matter of moments. System preferences>Users and Groups>Login items Here she advised me to select and removedrop box. After 4 hours of sleep my battery is still at 100%. Not an apple issue, a bad dropbox update. Updated dropbox this evening and reenabled it as a start up item. No drain yet.