Long-term current instability will reduce the battery's charging and discharging efficiency, and may even cause the battery to swell or become damaged.
What happens when a battery is fully charged?
At this stage, the battery voltage remains relatively constant, while the charging current continues to decrease. Charging Termination: The charging process is considered complete when the charging current drops to a specific predetermined value, often around 5% of the initial charging current.
What happens if a laptop gets a power fluctuation?
If your laptop does become a victim of a power fluctuation without any protection, the effects are often long-lasting. When a power fluctuation reaches their laptop, the battery becomes damaged. The battery either won't be able to hold a charge, or it will run down faster.
What happens if a laptop battery is damaged?
When a power fluctuation reaches their laptop, the battery becomes damaged. The battery either won't be able to hold a charge, or it will run down faster. Although the battery may be damaged, the laptop should still work plugged into an electrical outlet.
If it doesn't switch to battery (and doesn't shut down), that indicates that the charger is handling the voltage and will probably not be significantly affected. If it does switch to battery, the low voltage might shorten the life of the charger. Should you buy a UPS?
"A laptop battery could be prolonged by lowering the charge voltage when connected to the AC grid. To make this feature user-friendly, a device should feature a 'Long Life' mode that keeps the battery at 4.05V/cell and offers a SoC of about 80 percent.
Can AC voltage fluctuation damage a USB charger?
The AC voltage fluctuation could possibly damage the charger eventually, but as long as you are using a high quality charger, like the Apple-branded one, the DC output will be quite stable at 5V. You can buy a cheap device to measure this if you are curious. Google "USB charge doctor". You must log in to answer this question.