How to keep your Battery healthy
By: Daniel Hentzschel
Tags: Technology, Embedded Systems, Battery, Computers, Smartphones

Many people asked me how to really keep the battery’s life as long as possible. I’ll soon write my bachelor thesis in Computer Science at a Bavarian Technical University of Applied Sciences and had a basics course in Electrical Engineering. Due to the importance of such batteries in my study, I have learned more about it and have been informing my friends and family about the correct usage. I worked at a company in the field of digital health what brought me experience concerning the current topic.

LiPo batteries in a nutshell

A lithium polymer battery is rechargeable and of lithium-ion technology. The voltage of a LiPo cell varies from about 2.7 - 3.0 V (discharged) to about 4.2 V when fully charged. Usually, the embedded developers implement artificial voltage limits (low and high) to protect the battery a bit.

Temperatures and charging duration

LiPo cells don’t stand cold or hot temperatures in the long run. Further, they suffer damage when they get discharged them to 20 % or less too often. battery or charging it more than 80 %. It is better to charge your phone more often than discharging and charging it almost completely. You can charge a phone over 80 % without really damaging it, as long as you use the battery until you reach the limit of 80 % in the next minutes or rather hours.

Furthermore, the best idea would be to keep the battery level at 50 % which is impossible (more or less).

Got a new smartphone*! How to deal with it?

Yes, the rumor that the phone should not be used immediately after unpacking it is right. Often, the batteries are in a long-term preservation to prevent harming it while storing over months or years. To get the whole battery capacity, you can wake it up by charging it about 100 %. Note, you should use the 20 - 30 % in the following time. But after charging, you can install and initialize your device.

* a device running with a LiPo battery

Charging overnight

Generally, I try to avoid charging my iPhone overnight. In a normal night I definitely get more than 2 - 3 hours sleep which means the battery is still charging in the morning although it reached 100 %. As a battery, this must feel like hell. In the morning, while I have breakfast and a shower, the device is charged until a maximum of 80 % when needed.

Charging continuously

Some people don’t care about their laptop, they don’t disconnect the cable after reaching even 100 %. As I had to learn, batteries wear out very fast when you don’t unplug it from the power supply.

An artificial 80 % battery limit

Some manufacturers have a feature which stops the power supply when reaching 80 %. Apple, for instance, implemented a new feature using machine learning technology to learn when you wake up (to reach 100 % until then). It waits to finish charging past 80 % until you use it. I really can’t understand why anyone would implement such a feature while it would be way easier and more useful to implement an artificial limit of 80 %. This protection really helps the battery, because you could never overcharge it until you disable the feature (when you need the full capacity). The physical and software side implementation exists and works for a long time, the iPhone blocks the power supply when charging it with the laptop or other computers in some cases.

Monthly calibration

A battery should be calibrated every month. This can be done by discharging and charging it fully (yes, about 100 %). You can charge some minutes longer after reaching 100 % since the maximum battery is often less than 4.2 V. You should then have the full capacity again.

My experience

All my phones I had had their full capacity of 100 % for a very long time such as the current, which is about 9 months old. Of course, I have followed the tips above for years. I would recommend everyone who cares about battery capacity to follow my article.