Report Highlights need for battery charging re-education

How to charge phone batteries

The latest report from the Cadex Battery University, a world leader in battery testing, has highlighted the need for a mobile phone battery charging re-education.

Many battery charging myths have led to widely accepted ‘best practices’, but it turns out that many of these are unfounded and may actually be shortening the lifespan of the lithium-ion battery inside your smartphone.

The report, based upon real science, highlights what you should be doing to keep your Li-ion battery healthy. 

Fully charged

Your mobile phone battery does not need to be fully charged to 100 percent and it is in fact undesirable to do this. 

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Reaching 100 percent charge puts a high-voltage stress on the phone’s battery and it will remain in this high-voltage state for longer than a battery that isn’t charged to full. A battery that is charged to 85 percent will not reach the same high-voltage high-stress state and it will drop to an even safer voltage quicker.

Trickle charging

A Li-ion battery cannot absorb over charge and thus should be disconnected from the charger before this level is achieved. A mobile phone battery that is charged to full and is then left connected to a charger, will continue to trickle charge. This causes plating of metallic lithium, which is a damaging chemical reaction that will quickly lead to poor standby times.

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One of the most common examples of this, is those who charge their mobile phone overnight, which means that the battery spends hours in a trickle charging state.

Temperature and charging cycles

Heat is the worst enemy of Li-ion batteries and both charging and mobile phone use, cause the temperature of the battery to rise.

To avoid the damaging effects of high battery temperatures, it is best to remove the phone from its case first, if one is used, before charging. During charging, the battery should not be allowed to have more than a 10 degrees centigrade temperature rise.

If this occurs, then charging should be stopped until the battery cools down, meaning that contrary to popular belief, repeated short charging cycles are best . 

Lithium ion battery charging

There are several battery apps and widgets, that can be downloaded for free, that will show the battery temperature, making them a practical tool for monitoring the temperature while charging.

Another way to help avoid high battery temperatures when charging, is to charge the phone when it is off or at least when it is not being used. Charging a phone when it is standby, with the screen off, will also allow the battery to charge unhindered and thus place it under less stress.

Storing batteries

The report from the Cadex Battery University also highlighted that it is best to not leave a battery empty or fully charged, when it is not going to be used for some time. Ideally the phone’s battery should be charged to between 40 to 50 percent.

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Here is a summary of the best practices that will help you keep your battery healthy:

  • Do not charge the battery to 100 percent, 85 percent is best
  • Do not leave your phone charging overnight to avoid trickle charging
  • Charge your phone when it is not being used or for short cycles if it is
  • Partially charge your phone if it is to be left off for extended periods 

Written by: Michael Brown