Due to an increasing number of smartphones supporting wireless magnetic charging, more and more people are opting for wireless magnetic power banks that eliminate the need to carry charging cables, saving users from the hassle of dealing with wires. However, recently a netizen complained: “Even though the power bank was fully charged before I left the house, why does it lose some battery power for no reason when I take it out to use it? I wonder if the newly purchased power bank is defective?”
Why does the power of a newly purchased wireless magnetic power bank drain for no reason? How can you avoid this unexplained power drain issue? Here is an analysis and explanation:
Wireless magnetic power banks eliminate the hassle of tangled charging cables while supporting output power that increasingly rivals wired charging, making them more popular than ever. However, the wireless charging surface of magnetic power banks can experience unexplained self-discharge or weakened magnetic adhesion due to contact with metal or general wear and tear, so the precautions for carrying and using them differ from basic power banks. Below are explanations of the causes and solutions for unexplained self-discharge in magnetic power banks.
1. Causes of spontaneous self-discharge in magnetic wireless power banks:
Battery self-discharge refers to the natural loss of stored charge in a battery due to internal chemical reactions and physical factors, even when no external load is connected. However, a fully charged power bank within the warranty period typically has a normal self-discharge rate of 1% to 3% per month. If a power bank that was just fully charged shows a self-discharge exceeding 5% within a single day of no use, this indicates abnormal self-discharge and the cause of the unexplained power loss must be identified.
Why does a power bank under warranty show abnormal self-discharge after being fully charged? There are usually four reasons:
A. Wireless charging surface — keep away from metal objects:
Since wireless magnetic power banks are equipped with automatic detection in their wireless sensing devices, placing keys, coins, nail clippers, or other metal objects in the same bag or pocket as the power bank can cause the wireless charging surface to contact these metal objects. When this happens, the wireless sensor will continuously activate detection, resulting in power drain.
B. Place in a metallic aluminum foil explosion-proof bag:
To avoid the risk of personal injury from power banks self-igniting or catching fire, some people purchase explosion-proof bags for their power banks. However, some explosion-proof bags contain metallic aluminum foil, which can cause wireless activation sensor systems to continuously turn on and off, resulting in power drain.
C. Two magnetic wireless power banks attract each other
If users have two wireless magnetic power banks, and the two magnetic charging surfaces come into contact with each other, the wireless output systems of both devices will activate, resulting in power consumption.
D. Chinese-made battery cell failure:
Commercially available Chinese-made power banks may not undergo burn-in testing before leaving the factory, which means potential manufacturing defects like poor insulation or microscopic short circuits cannot be filtered out, leading to unexplained power drain in newly purchased power banks.
How to prevent magnetic power banks from self-discharging without use?
To prevent wireless magnetic power banks from experiencing unexplained self-discharge or user-caused damage, the following safety precautions are recommended:
A. Store separately, preferably in a flannel bag.
When storing a magnetic power bank in a bag, it’s best to keep it separate. Avoid letting the wireless charging surface come into contact with metal objects such as keys, coins, etc., or another magnetic power bank. It’s recommended to place it in a separate pouch (such as a fleece bag) to prevent friction from scratching the magnetic surface and affecting its magnetic adhesion, and also to reduce contact with the wireless charging surface. If you have purchased an explosion-proof bag for power banks, do not put a normal magnetic power bank inside the explosion-proof bag.
Randomly included fleece bag for Enerpad UFO Solid-State Magnetic Power Bank
B. Avoid prolonged close contact with mobile phones
Prolonged attachment of a magnetic power bank to your phone while placed in a hot, sun-exposed car interior or leather case can easily lead to overheating, reducing product lifespan or causing product malfunction and personal injury hazards.
C. Avoid charging while walking
Magnetically attached portable power banks used for prolonged charging while walking with your phone can easily experience poor contact due to vibration. Additionally, the significant movement while walking can cause intermittent power disconnection and reconnection, leading to faster battery drain, or the power bank may fall and get damaged. It’s recommended to use while seated instead.
Source: KOCPC Chinese