Does it hurt the battery to leave a brand new phone in its box for months without charging it up?

Note that your lithium battery degrades whether used or not. Every lithium battery has a finite life span, and if left truly static on a shelf for a many months or a year or so will show substantial degradation or be useless.

Lithium batteries, once assembled at the factory, will provide the longest useful lifespan if they experience regular use (partial discharge/charge cycles). So buying a “spare” and just letting it sit idle for many months or longer is basically counter productive. Rechargeable Lithium batteries are best bought when needed, and then used for as long as they provide useable capacity.

At least once a week or so it would be best then to turn that phone on for awhile and then charge it some so it gets some active current flow through it.

For long term storage, the battery should ideally be changed to 50%. Just like notebooks.

Batteries - Maximizing Performance - Apple

No.

Lithium-ion batteries ( your phone's battery ) are designed such that for long-term storage, the battery should be at around 50% charge level. Every several months, power your phone, check battery level and charge it up to 50% if charge level has dropped.

As was pointed out, beware of your warranty, too.

The only thing I’d add to the other comments is don’t stress if you go slightly above 50%. It should be somewhere in the middle of the charge range, and 50% is a nice round number. Also, don’t forget to turn it off before you put it back in storage.

Michael Black wrote:

Note that your lithium battery degrades whether used or not. Every lithium battery has a finite life span, and if left truly static on a shelf for a many months or a year or so will show substantial degradation or be useless.

I read some article about how Tesla car batteries are being used. There's this one guy who is recommending programming Tesla batteries to stop charging at 80% (or even 70%) in order to exponentially increase the expected lifespan of the battery. He stated that he might be able to get 20 years of service out of it by avoiding the top of the charge range but using the vehicle regularly.

https://electrek.co/2017/09/01/tesla-battery-expert-recommends-daily-battery-pac k-charging/

Elon Musk talks about using only the 80% to 30% range. If all one ever does is short trips, that's easily possible. Maybe don't actually force it to stop at 30%, but trigger a "nag" notice at 40% telling the owner to find a charging station quickly.

However, I don't really expect that the average owner of an iPhone really wants to use only half the capacity of the battery in order to keep the battery forever. But one also doesn't want a battery to die early in storage. Still - it's easy enough to get a new battery, and who knows if Apple is going to maintain a lower battery service price after this current promotion ends.

Large lithium batteries for cars, commercial vehicles like fork lifts and such are also constructed differently than the small compact lithium polymer batteries used in consumer electronics. They use different electrolytes and other components so they do behave differently.

I just read an article on another novel lithium cell for large commercial scale applications where a novel electrolyte allows the battery to function down to -70 degrees centigrade.

Just to make the point that not all batteries referred to as lithium based are constructed the same, perform similarly or last comparably. Low cost, small form factor consumer electronics lithium batteries are just one class of lithium battery being produced. And their technology doesn’t necessarily even scale well much beyond human portable electronic devices.

Michael Black wrote:

Large lithium batteries for cars, commercial vehicles like fork lifts and such are also constructed differently than the small compact lithium polymer batteries used in consumer electronics. They use different electrolytes and other components so they do behave differently.

Sure. However, many believe that a similar strategy to always limit the charge range of a small device battery could exponentially increase battery longevity in portable devices. For something like an iPhone that would either mean severely over-provisioning the capacity of the battery or dealing with about half the useful capacity. You can program the battery management in some notebook computers to limit the charge range.

I can deal with having a rated 10 hours of use where I might need to replace the battery every 2-3 years. What's the use of having a battery that won't need to be replaced for 10 years when it will be obsolete by then and I can only use it for 5 hours at a time?

I would do that. Be aware of another matter too, your warranty started on the day you purchased the phone, not when you first enable it.

Hi

Yes charge every few weeks.

Cheers

Brian 🇬-1F1E7;

Try to keep the battery level around 50% as it is harmful for the battery to fully discharged and kept for a long time.