How to fix iPhone battery shutting off in cold
Do you have an iPhone that battery randomly shuts off in the cold?
This is a common problem faced by many users with batteries in the colder climates.
The iPhone Battery
All iPhones use a type of battery called Lithium-Ion (sometimes abbreviated Li-ion). This is the most common battery technology found in rechargeable devices.
Li-ion batteries carry certain advantages – they charge fairly quickly and don’t need to be completely depleted before recharging (in fact, it’s better to recharge at 20% then waiting for your phone to die). Unfortunately, these batteries don’t do so well when the temperature outside drops.
Lithium-Ion batteries suffer in extreme cold temperatures:
According to Battery University, cold temperature “increases the internal resistance and diminishes the capacity” of a Li-ion battery. Specifically, they estimate that at -18 degrees Celcius a Li-ion may only deliver 50% of its capacity.
During last winter’s Polar Vortex, Global news did an experiment which showed an iPhone left outside dropped 14% in only 30 minutes, while an identical phone left inside dropped only 1%.
Apple specifies that their batteries work best at a range of 0 degrees Celsius to 35 degrees Celsius. While we almost never reach the upper range in Canada, temperatures below freezing are typical for the winer months.
Because the battery meter is calibrated assuming warmer temperatures, the reduced capacity in the cold can cause the reading to be unreliable. This is one of the reasons your phone may die while still showing 30%.
All cell phones use Lithium-Ion batteries and as such as subject to this problem. This issue is also exacerbated when the battery itself has been used for a great deal of time (>1yr) and is already week due to the high cycle counts incurred from multiple charges.