Why don't sellers just ship their laptop batteries fully charged?
I could tell you (if you don't know yet) that laptop batteries, in general, are a prime example of the phenomena called "planned obsolescence". They are over-designed & fabricated in a way that they fail (but in a specific way).
For example, when you buy a new laptop battery you are given a number of 200/300 cycles charge-discharge which you will most likely use up within the warranty time of 1-2 years. A charge cycle happens when you use all of the battery’s power—but that doesn’t necessarily mean in a single charge.
For example, when you buy a new laptop battery, it goes through 200/300 charge and discharge cycles, and you will most likely run out of it within the 1-2 year warranty. A charge cycle happens when you use up all of the battery's charge, but that doesn't necessarily mean a single charge.
When you use half of your laptop's power in a day, then fully charge it. If you do the same thing the next day, it will count as one charge cycle, not two. In this example, it may take several days to complete a cycle.
B31N1912 C31N1912 Kingsener Laptop Battery For ASUS VivoBook 14 E410MA L410MA E410KA E510MA E510KA F414MA E410MA-EK026TS EK018TS 42WH 11.55V
Keep in mind that new laptop batteries normally come pre-charged to around somewhere 30 - 40 % of their capacity. This would roughly equate per each 18650 battery inside the battery pack to around 3,6 - 3,8 V.
You might ask yourself well why don't manufacturers/sellers just ship their laptop batteries fully charged (100 %) instead ?
Well this applies to just about any rechargeable battery out there - if you re-charge it to 100 %, you have to use it pretty much at once , definitely within a day.
Due to if you leave the battery resting for weeks not used,but fully charged, it may occur that due to the internal stress and chemistry, the voltage of the battery might one day just simply decide to quit. Meaning that it might (in a worse case scenario) drop to even 0 V.
In lesser cases, it would get below the level where the charger you are using might be able to recharge it back up. For 18650 batteries that would be below 3 V.
Once a battery goes down this path you can pretty much have to discard it. It can be recharged but her capacity might be already affected,meaning diminished since its factory stated.
The best thing you can do is try to keep the battery level between 40 percent to 80 percent. Make sure that your laptop doesn't get too hot and that your cooling fan is working properly. Your laptop battery can't “overcharge” and harm itself due to excessive charging.
Since laptop batteries manufacturers/sellers don't know when they'll be able to sell X amount of Acer, HP, Asus, etc. batteries per month & it's much "safer" to pre-charge them to a certain level so they can be resting in the storage/warehouse waiting for their new owners.
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