Planning to switch off and shut down my phone for few months. Will device get unusable?

[Projection Theory]

My battery is 80% now. It's a Li-Po non-removable battery. Phone is lenovo k4 note.
It has happened before . After leaving the phone idle and inactive 4/5 months, I suddenly found the phone dead... It was not starting... I am using a different phone now, so do I need to charge my old phone regularly if I don't want it to go dead?

 

[anon(238680)]

do I need to charge my old phone regularly if I don't want it to go dead?

Welcome to Android Central. Yes, charge the battery enough to keep it from going dead and you should be fine.

 

[Mooncatt]

Get the battery down between 50-75% before storing it. It will drop a little bit over time, but only a few percentage points for 4-5 months storage. This will help protect the battery from degradation. If you really want to go the extra mile, stick it in a refrigerator. Keeping it cool can further protect it from degradation.

 

[Projection Theory]

Get the battery down between 50-75% before storing it. It will drop a little bit over time, but only a few percentage points for 4-5 months storage.

O thanks for the help.. So are you sure that if I switch off the phone for 4/5 months while the battery is around 70%, it will be okay? And speaking of the cryogenic preservation technique I gotta say it was innovative. You don't think that such a low temperature environment inside the refrigerator would impact its softwares badly? Thanks for the tips

 

[Mooncatt]

O thanks for the help.. So are you sure that if I switch off the phone for 4/5 months while the battery is around 70%, it will be okay? And speaking of the cryogenic preservation technique I gotta say it was innovative. You don't think that such a low temperature environment inside the refrigerator would impact its softwares badly? Thanks for the tips

That 50-75% window is known as storage charge. The lower, the better, so long as you make sure to keep it from going too low due to self discharging. I've put my backup phone into storage at about 70% and it was fine 6 months later. They ship from the factories in storage charge for the same reason because it may sit on a shelf for months before being used.

If the battery is removable, then I'd only stick it in the fridge by itself. If not removable, I'd seal it in a bag and suck all the air out to prevent condensation when you pull it out and let it warm to room temp before opening the bag. The cold in and of itself won't cause problems, but I wouldn't stick it in a freezer. The fridge method is somewhat common in the RC hobbies. They will charge batteries the day before use and store them in the fridge to preserve them from as much damage while saving them time the next morning by not having to charge them.