Battery drain after switching to new phone

[yarnsrj]

I know this has been beaten to death but it's a new one for me... That being said, I recently transferred service from my 2.5 yr old Verizon variant galaxy Note 3 to my new Note 5. I do still use my Note 3 on Wi-Fi because I have old games and my ebooks on the phone. However almost immediately the battery drain in my Note 3 has turned into crap. Most of the battery usage is "phone and cell standby" and I'm not sure why as I've not seen that kind of usage when I had service on the phone. I use the phone minimally and within a couple of hours more than 50% drain, and by the end of the day ( 12-14 hrs) it shut off. Can someone explain this usage all of a sudden and what does "phone" actually mean if I no longer have service on this phone Here is a screenshot

 

[yarnsrj]

Help, anyone?

 

[humpagardengnome]

Noticed my phone did the same for a few hours after I shut off vzw service but before activating a new T-Mo sim. I had 100% steady LTE signal pre shutoff. Post shutoff, the cell signal bars were constantly switching from E only to 1xRTT and 3G. Phone & cell standby were abnormally high in battery usage stats. Stopped cycling and sits steadily in LTE coverage once I reactivated cell service with T-Mo.

 

[yarnsrj]

I posted this issue in another forum and here is what was suggested for me to do from member, B. Diddy, and it worked like a charm... "Verizon phones don't use a SIM for cell service, so it may be that the phone's CDMA radio is still trying to latch onto some kind of signal (even though the phone is no longer activated on your line). Since you only use the phone as a wi-fi device, turn on Airplane Mode (which turns off all radios including the cell radio), then turn wi-fi back on. The cell radio will remain off".