Will my razer Blade 15 base 2020 be overcharged if I leave it for a charge a long time?

No. The Razer Blade series uses a lithium-ion (Li-On) polymer battery. The Blade laptops have an internal circuit to stop charging at full charge to avoid overcharging and will only start recharging when the battery hits 95%.

Note: It is highly recommended to cycle the battery every couple of weeks.

The above sources from official website.

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